From 5a1bf286e86c277c02589e1b3400ae903a38f3863d488f1d8444a58cf176106f Mon Sep 17 00:00:00 2001
From: Benjamin Greiner <code@bnavigator.de>
Date: Sun, 4 Jul 2021 14:22:22 +0000
Subject: [PATCH] Accepting request 903959 from
 home:bnavigator:branches:devel:languages:python:numeric

- Replace astropy-pr11260-wcsfailures.patch with
  astropy-pr11260+pr11549-wcs76.patch
  * fixes test failures because of the recent Tumbleweed update to
    wcslib 7.6
  * include binary test file tab-time-last-axis.fits from
    gh#astropy/astropy#11549, which does not fit into the patchfile

OBS-URL: https://build.opensuse.org/request/show/903959
OBS-URL: https://build.opensuse.org/package/show/devel:languages:python:numeric/python-astropy?expand=0&rev=55
---
 .gitattributes                                |     2 +
 ...tch => astropy-pr11260+pr11549-wcs76.patch | 14955 +++++++++++-----
 python-astropy.changes                        |    10 +
 python-astropy.spec                           |    10 +-
 tab-time-last-axis.fits                       |     3 +
 5 files changed, 10987 insertions(+), 3993 deletions(-)
 rename astropy-pr11260-wcsfailures.patch => astropy-pr11260+pr11549-wcs76.patch (73%)
 create mode 100644 tab-time-last-axis.fits

diff --git a/.gitattributes b/.gitattributes
index 9b03811..4d13305 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -21,3 +21,5 @@
 *.xz filter=lfs diff=lfs merge=lfs -text
 *.zip filter=lfs diff=lfs merge=lfs -text
 *.zst filter=lfs diff=lfs merge=lfs -text
+## Specific LFS patterns
+tab-time-last-axis.fits filter=lfs diff=lfs merge=lfs -text
diff --git a/astropy-pr11260-wcsfailures.patch b/astropy-pr11260+pr11549-wcs76.patch
similarity index 73%
rename from astropy-pr11260-wcsfailures.patch
rename to astropy-pr11260+pr11549-wcs76.patch
index 4bf3d21..ba82df9 100644
--- a/astropy-pr11260-wcsfailures.patch
+++ b/astropy-pr11260+pr11549-wcs76.patch
@@ -118,10 +118,10 @@ and enhancements, as per the change log appended below.
  cextern/wcslib/wcsconfig_utils.h.in |    4 +-
  67 files changed, 5703 insertions(+), 5580 deletions(-)
 
-Index: astropy-4.2/astropy/wcs/setup_package.py
+Index: astropy-4.2.1/astropy/wcs/setup_package.py
 ===================================================================
---- astropy-4.2.orig/astropy/wcs/setup_package.py
-+++ astropy-4.2/astropy/wcs/setup_package.py
+--- astropy-4.2.1.orig/astropy/wcs/setup_package.py
++++ astropy-4.2.1/astropy/wcs/setup_package.py
 @@ -16,7 +16,7 @@ import numpy
  from extension_helpers import import_file, write_if_different, get_compiler, pkg_config
  
@@ -131,14 +131,25 @@ Index: astropy-4.2/astropy/wcs/setup_package.py
  
  
  def b(s):
-Index: astropy-4.2/cextern/wcslib/C/GNUmakefile
+@@ -227,6 +227,10 @@ def get_wcslib_cfg(cfg, wcslib_files, in
+     if sys.platform.startswith('linux'):
+         cfg['define_macros'].append(('HAVE_SINCOS', None))
+ 
++    # For 4.7+ enable C99 syntax in older compilers (need 'gnu99' std for gcc)
++    if get_compiler() == 'unix':
++        cfg['extra_compile_args'].extend(['-std=gnu99'])
++
+     # Squelch a few compilation warnings in WCSLIB
+     if get_compiler() in ('unix', 'mingw32'):
+         if not debug:
+Index: astropy-4.2.1/cextern/wcslib/C/GNUmakefile
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/GNUmakefile
-+++ astropy-4.2/cextern/wcslib/C/GNUmakefile
+--- astropy-4.2.1.orig/cextern/wcslib/C/GNUmakefile
++++ astropy-4.2.1/cextern/wcslib/C/GNUmakefile
 @@ -1,5 +1,5 @@
  #-----------------------------------------------------------------------------
 -# GNU makefile for building WCSLIB 7.3 and its test suite.
-+# GNU makefile for building WCSLIB 7.4 and its test suite.
++# GNU makefile for building WCSLIB 7.6 and its test suite.
  #
  # Summary of the main targets
  # ---------------------------
@@ -147,20 +158,203 @@ Index: astropy-4.2/cextern/wcslib/C/GNUmakefile
  # Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
  # http://www.atnf.csiro.au/people/Mark.Calabretta
 -# $Id: GNUmakefile,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+# $Id: GNUmakefile,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++# $Id: GNUmakefile,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  #-----------------------------------------------------------------------------
  # Get configure settings.
  SUBDIR := C
-Index: astropy-4.2/cextern/wcslib/C/cel.c
+@@ -78,9 +78,12 @@ TEST_C := twcstab twcshdr tdis3 twcslint
+ # Test programs that require PGPLOT but not PGSBOX.
+ TEST_P := tspc tprj2 tcel1 tcel2 ttab2 ttab3 twcsmix
+ 
+-# Test programs that require PGPLOT and PGSBOX.
++# Test programs that require PGSBOX (and therefore PGPLOT).
+ TEST_B := tpih2
+ 
++# Test program for POSIX threads (code development only).
++TEST_T := tpthreads
++
+ # Test programs that are compiled but not automatically exercised.
+ TEST_X := tsphdpa twcshdr
+ 
+@@ -88,24 +91,39 @@ TEST_X := tsphdpa twcshdr
+ TESTS  := $(TEST_N)
+ 
+ # Do we have CFITSIO?
+-ifeq "$(CFITSIOINC)$(CFITSIOLIB)" ""
+-  # No, amend TEST_X.
+-  TEST_X := $(filter-out $(TEST_C),$(TEST_X))
+-else
++DO_CFITSIO := 1
++ifeq "$(CFITSIOINC)" ""
++  DO_CFITSIO := 0
++else ifeq "$(CFITSIOLIB)" ""
++  DO_CFITSIO := 0
++endif
++
++ifeq "$(DO_CFITSIO)" "1"
+   # Yes, add test programs that use it.
+   TESTS += $(TEST_C)
+   CFITSIO_CFLAGS := $(filter-out -Wpadded,$(CFLAGS))
++else
++  # No, amend TEST_X.
++  TEST_X := $(filter-out $(TEST_C),$(TEST_X))
+ endif
+ 
+ # Do we have PGPLOT?
++DO_PGPLOT := 0
+ ifneq "$(CHECK)" "nopgplot"
+-ifeq "$(PGPLOTINC)$(PGPLOTLIB)" ""
+-  # No, amend TEST_X.
+-  TEST_X := $(filter-out $(TEST_P) $(TEST_B),$(TEST_X))
+-else
+-  # Yes, add test programs that use it.
+-  TESTS += $(TEST_P) $(TEST_B)
+-endif
++  DO_PGPLOT := 1
++  ifeq "$(PGPLOTINC)" ""
++    DO_PGPLOT := 0
++  else ifeq "$(PGPLOTLIB)" ""
++    DO_PGPLOT := 0
++  endif
++
++  ifeq "$(DO_PGPLOT)" "1"
++    # Yes, add test programs that use it.
++    TESTS += $(TEST_P) $(TEST_B)
++  else
++    # No, amend TEST_X.
++    TEST_X := $(filter-out $(TEST_P) $(TEST_B),$(TEST_X))
++  endif
+ endif
+ 
+ # Remove tests that aren't automatically exercised.
+@@ -248,7 +266,7 @@ run_% : %
+ #--------------------------------
+ 
+ .PHONY : build check clean cleaner cleanest distclean install lib realclean \
+-         run_% test tests
++         run_% test tests uninstall
+ 
+ build : lib
+ 
+@@ -338,13 +356,18 @@ install : build
+ 	-  $(RM) $(INCLINK)
+ 	   $(LN_S) $(notdir $(INCDIR)) $(INCLINK)
+ 
++uninstall :
++	-  cd $(LIBDIR) && $(RM) $(WCSLIB) $(SHRLN) $(SONAME) $(SHRLIB)
++	-  $(RM) $(INCDIR)
++	-  $(RM) $(INCLINK)
++
+ clean :
+ 	- $(RM) *.o $(LIBLOCK) *.i a.out t*.out core *.dSYM
+ 	- $(RM) -r $(EXTRA_CLEAN)
+ 
+ cleaner : clean
+ 	-  $(RM) .gdb_history
+-	-  $(RM) $(TEST_N) $(TEST_n) $(TEST_X)
++	-  $(RM) $(TEST_N) $(TEST_n) $(TEST_T) $(TEST_X)
+ 	-  $(RM) $(TEST_P) tdis3 tpih2 twcshdr twcslint twcstab
+ 	-  $(RM) tofits
+ 	-  $(RM) bth.fits fitshdr.fits pih.fits wcslint.fits wcstab.fits
+@@ -361,38 +384,20 @@ check test : tests $(TESTS:%=run_%)
+ 
+ tests : $(TESTS) $(TEST_X)
+ 
++# TEST_N and TEST_n programs (no special libraries required).
+ $(TEST_N) $(TEST_n) : % : test/%.c $(WCSLIB)
+ 	-@ echo ''
+ 	   $(CC) $(CPPFLAGS) $(CFLAGS) -o $@ $< $(LDFLAGS) $(WCSLIB) $(LIBS)
+ 	-@ $(RM) $@.o
+ 
+-$(TEST_P) : % : test/%.c $(WCSLIB)
+-	-@ echo ''
+-	   $(CC) $(CPPFLAGS) $(PGPLOTINC) $(CFLAGS) -c -o $@.o $<
+-	   $(LD) -o $@ $@.o $(LDFLAGS) $(PGPLOTLIB) $(WCSLIB) $(FLIBS) $(LIBS)
+-	-@ $(RM) $@.o
+-
+-tpih2 : test/tpih2.c $(PGSBOXLIB) $(WCSLIB)
+-	-@ echo ''
+-	   $(CC) $(CPPFLAGS) -I../pgsbox $(PGPLOTINC) $(CFLAGS) -c -o $@.o $<
+-	   $(LD) -o $@ $@.o $(LDFLAGS) $(PGSBOXLIB) $(PGPLOTLIB) $(WCSLIB) \
+-	     $(FLIBS) $(LIBS)
+-	-@ $(RM) $@.o
+-
+-tfitshdr_cfitsio tpih1_cfitsio tbth1_cfitsio : %_cfitsio : test/%.c $(WCSLIB)
++# TEST_N programs (optionally using CFITSIO).
++tpih1_cfitsio tbth1_cfitsio tfitshdr_cfitsio : %_cfitsio : test/%.c $(WCSLIB)
+ 	-@ echo ''
+ 	   $(CC) -DDO_CFITSIO $(CPPFLAGS) $(CFITSIOINC) $(CFITSIO_CFLAGS) \
+ 	     -o $@ $< $(LDFLAGS) $(CFITSIOLIB) $(WCSLIB) $(LIBS)
+ 	-@ $(RM) $@.o
+ 
+-tpih2_cfitsio : test/tpih2.c $(PGSBOXLIB) $(WCSLIB)
+-	-@ echo ''
+-	   $(CC) -DDO_CFITSIO $(CPPFLAGS) -I../pgsbox $(PGPLOTINC) \
+-	     $(CFITSIOINC) $(CFITSIO_CFLAGS) -c -o $@.o $<
+-	   $(LD) -o $@ $@.o $(LDFLAGS) $(PGSBOXLIB) $(PGPLOTLIB) \
+-	     $(CFITSIOLIB) $(WCSLIB) $(FLIBS) $(LIBS)
+-	-@ $(RM) $@.o
+-
++# TEST_C programs (using CFITSIO).
+ twcstab : test/twcstab.c $(WCSLIB) $(GETWCSTAB)
+ 	-@ echo ''
+ 	   $(CC) $(CPPFLAGS) $(CFITSIOINC) $(CFITSIO_CFLAGS) -o $@ $< \
+@@ -415,6 +420,36 @@ twcslint : test/twcslint
+ 	   cp $< .
+ 	-@ chmod a+x $@
+ 
++# TEST_P programs (using PGPLOT).
++$(TEST_P) : % : test/%.c $(WCSLIB)
++	-@ echo ''
++	   $(CC) $(CPPFLAGS) $(PGPLOTINC) $(CFLAGS) -c -o $@.o $<
++	   $(LD) -o $@ $@.o $(LDFLAGS) $(PGPLOTLIB) $(WCSLIB) $(FLIBS) $(LIBS)
++	-@ $(RM) $@.o
++
++# TEST_B programs (PGSBOX and PGPLOT).
++tpih2 : test/tpih2.c $(PGSBOXLIB) $(WCSLIB)
++	-@ echo ''
++	   $(CC) $(CPPFLAGS) -I../pgsbox $(PGPLOTINC) $(CFLAGS) -c -o $@.o $<
++	   $(LD) -o $@ $@.o $(LDFLAGS) $(PGSBOXLIB) $(PGPLOTLIB) $(WCSLIB) \
++	     $(FLIBS) $(LIBS)
++	-@ $(RM) $@.o
++
++tpih2_cfitsio : test/tpih2.c $(PGSBOXLIB) $(WCSLIB)
++	-@ echo ''
++	   $(CC) -DDO_CFITSIO $(CPPFLAGS) -I../pgsbox $(PGPLOTINC) \
++	     $(CFITSIOINC) $(CFITSIO_CFLAGS) -c -o $@.o $<
++	   $(LD) -o $@ $@.o $(LDFLAGS) $(PGSBOXLIB) $(PGPLOTLIB) \
++	     $(CFITSIOLIB) $(WCSLIB) $(FLIBS) $(LIBS)
++	-@ $(RM) $@.o
++
++# TEST_T programs (using POSIX threads).
++tpthreads : test/tpthreads.c $(WCSLIB)
++	-@ echo ''
++	   $(CC) $(CPPFLAGS) $(CFLAGS) -pthread -c -o $@.o $<
++	   $(LD) -o $@ $@.o $(LDFLAGS) -pthread $(WCSLIB) -lpthread $(LIBS)
++	-@ $(RM) $@.o
++
+ getwcstab.o : getwcstab.c getwcstab.h
+ 	-@ echo ''
+ 	   $(CC) $(CPPFLAGS) $(CFITSIO_CFLAGS) $(CFITSIOINC) -c $<
+@@ -436,6 +471,8 @@ GNUmakefile : ../makedefs ;
+ show ::
+ 	-@ echo '  FLEXMODS    := $(FLEXMODS)'
+ 	-@ echo '  MODULES     := $(MODULES)'
++	-@ echo '  DO_CFITSIO  := $(DO_CFITSIO)'
++	-@ echo '  DO_PGPLOT   := $(DO_PGPLOT)'
+ 	-@ echo '  TESTS       := $(TESTS)'
+ 	-@ echo '  TEST_X      := $(TEST_X)'
+ 
+Index: astropy-4.2.1/cextern/wcslib/C/cel.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/cel.c
-+++ astropy-4.2/cextern/wcslib/C/cel.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/cel.c
++++ astropy-4.2.1/cextern/wcslib/C/cel.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -174,7 +368,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: cel.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: cel.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: cel.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <math.h>
@@ -224,16 +418,45 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
  
  int celfree(struct celprm *cel)
  
-@@ -99,7 +96,7 @@ int celfree(struct celprm *cel)
+@@ -99,7 +96,36 @@ int celfree(struct celprm *cel)
    return cel_prjerr[prjfree(&(cel->prj))];
  }
  
 -/*--------------------------------------------------------------------------*/
++//----------------------------------------------------------------------------
++
++int celsize(const struct celprm *cel, int sizes[2])
++
++{
++  if (cel == 0x0) {
++    sizes[0] = sizes[1] = 0;
++    return CELERR_SUCCESS;
++  }
++
++  // Base size, in bytes.
++  sizes[0] = sizeof(struct celprm);
++
++  // Total size of allocated memory, in bytes.
++  sizes[1] = 0;
++
++  int exsizes[2];
++
++  // celprm::prj.
++  prjsize(&(cel->prj), exsizes);
++  sizes[1] += exsizes[1];
++
++  // celprm::err.
++  wcserr_size(cel->err, exsizes);
++  sizes[1] += exsizes[0] + exsizes[1];
++
++  return CELERR_SUCCESS;
++}
++
 +//----------------------------------------------------------------------------
  
  int celprt(const struct celprm *cel)
  
-@@ -156,7 +153,7 @@ int celprt(const struct celprm *cel)
+@@ -156,7 +182,7 @@ int celprt(const struct celprm *cel)
    return 0;
  }
  
@@ -242,7 +465,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
  
  int celperr(const struct celprm *cel, const char *prefix)
  
-@@ -171,7 +168,7 @@ int celperr(const struct celprm *cel, co
+@@ -171,7 +197,7 @@ int celperr(const struct celprm *cel, co
  }
  
  
@@ -251,7 +474,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
  
  int celset(struct celprm *cel)
  
-@@ -189,13 +186,13 @@ int celset(struct celprm *cel)
+@@ -189,13 +215,13 @@ int celset(struct celprm *cel)
    if (cel == 0x0) return CELERR_NULL_POINTER;
    err = &(cel->err);
  
@@ -267,7 +490,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
      celprj->phi0   = UNDEFINED;
      celprj->theta0 = UNDEFINED;
    }
-@@ -204,7 +201,7 @@ int celset(struct celprm *cel)
+@@ -204,7 +230,7 @@ int celset(struct celprm *cel)
      return wcserr_set(CEL_ERRMSG(cel_prjerr[status]));
    }
  
@@ -276,7 +499,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
    if (undefined(cel->phi0)) {
      cel->phi0 = celprj->phi0;
    }
-@@ -231,7 +228,7 @@ int celset(struct celprm *cel)
+@@ -231,7 +257,7 @@ int celset(struct celprm *cel)
    phip = cel->ref[2];
    latp = cel->ref[3];
  
@@ -285,7 +508,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
    if (undefined(phip) || phip == 999.0) {
      phip = (lat0 < cel->theta0) ? 180.0 : 0.0;
      phip += cel->phi0;
-@@ -246,15 +243,15 @@ int celset(struct celprm *cel)
+@@ -246,15 +272,15 @@ int celset(struct celprm *cel)
    }
  
  
@@ -304,7 +527,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
      sincosd(lat0, &slat0, &clat0);
      sincosd(cel->theta0, &sthe0, &cthe0);
  
-@@ -278,7 +275,7 @@ int celset(struct celprm *cel)
+@@ -278,7 +304,7 @@ int celset(struct celprm *cel)
              "lat0 == 0 is required for |phip - phi0| = 90 and theta0 == 0");
          }
  
@@ -313,7 +536,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
          cel->latpreq = 2;
          if (latp > 90.0) {
            latp = 90.0;
-@@ -286,7 +283,7 @@ int celset(struct celprm *cel)
+@@ -286,7 +312,7 @@ int celset(struct celprm *cel)
            latp = -90.0;
          }
  
@@ -322,7 +545,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
  	u = v = 0.0;
  
        } else {
-@@ -327,7 +324,7 @@ int celset(struct celprm *cel)
+@@ -327,7 +353,7 @@ int celset(struct celprm *cel)
  
        if (fabs(latp1) < 90.0+tol &&
            fabs(latp2) < 90.0+tol) {
@@ -331,7 +554,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
          cel->latpreq = 1;
        }
  
-@@ -345,7 +342,7 @@ int celset(struct celprm *cel)
+@@ -345,7 +371,7 @@ int celset(struct celprm *cel)
          }
        }
  
@@ -340,7 +563,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
        if (fabs(latp) < 90.0+tol) {
          if (latp > 90.0) {
            latp =  90.0;
-@@ -358,15 +355,15 @@ int celset(struct celprm *cel)
+@@ -358,15 +384,15 @@ int celset(struct celprm *cel)
      z = cosd(latp)*clat0;
      if (fabs(z) < tol) {
        if (fabs(clat0) < tol) {
@@ -359,7 +582,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
          lngp = lng0 - phip + cel->phi0;
        }
  
-@@ -374,15 +371,15 @@ int celset(struct celprm *cel)
+@@ -374,15 +400,15 @@ int celset(struct celprm *cel)
        x = (sthe0 - sind(latp)*slat0)/z;
        y =  sphip*cthe0/clat0;
        if (x == 0.0 && y == 0.0) {
@@ -378,7 +601,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
      if (lng0 >= 0.0) {
        if (lngp < 0.0) {
          lngp += 360.0;
-@@ -398,10 +395,10 @@ int celset(struct celprm *cel)
+@@ -398,10 +424,10 @@ int celset(struct celprm *cel)
      }
    }
  
@@ -391,7 +614,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
    cel->euler[0] = lngp;
    cel->euler[1] = 90.0 - latp;
    cel->euler[2] = phip;
-@@ -409,7 +406,7 @@ int celset(struct celprm *cel)
+@@ -409,7 +435,7 @@ int celset(struct celprm *cel)
    cel->isolat = (cel->euler[4] == 0.0);
    cel->flag = CELSET;
  
@@ -400,7 +623,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
    if (fabs(latp) > 90.0+tol) {
      return wcserr_set(WCSERR_SET(CELERR_ILL_COORD_TRANS),
        "Ill-conditioned coordinate transformation parameters\nNo valid "
-@@ -419,7 +416,7 @@ int celset(struct celprm *cel)
+@@ -419,7 +445,7 @@ int celset(struct celprm *cel)
    return 0;
  }
  
@@ -409,7 +632,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
  
  int celx2s(
    struct celprm *cel,
-@@ -442,7 +439,7 @@ int celx2s(
+@@ -442,7 +468,7 @@ int celx2s(
    struct prjprm *celprj;
    struct wcserr **err;
  
@@ -418,7 +641,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
    if (cel == 0x0) return CELERR_NULL_POINTER;
    err = &(cel->err);
  
-@@ -450,7 +447,7 @@ int celx2s(
+@@ -450,7 +476,7 @@ int celx2s(
      if ((status = celset(cel))) return status;
    }
  
@@ -427,7 +650,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
    celprj = &(cel->prj);
    if ((istat = celprj->prjx2s(celprj, nx, ny, sxy, 1, x, y, phi, theta,
                                 stat))) {
-@@ -464,13 +461,13 @@ int celx2s(
+@@ -464,13 +490,13 @@ int celx2s(
  
    nphi = (ny > 0) ? (nx*ny) : nx;
  
@@ -443,7 +666,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
  
  int cels2x(
    struct celprm *cel,
-@@ -493,7 +490,7 @@ int cels2x(
+@@ -493,7 +519,7 @@ int cels2x(
    struct prjprm *celprj;
    struct wcserr **err;
  
@@ -452,7 +675,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
    if (cel == 0x0) return CELERR_NULL_POINTER;
    err = &(cel->err);
  
-@@ -501,11 +498,11 @@ int cels2x(
+@@ -501,11 +527,11 @@ int cels2x(
      if ((status = celset(cel))) return status;
    }
  
@@ -466,7 +689,7 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
      nphi   = nlng;
      ntheta = nlat;
    } else {
-@@ -513,7 +510,7 @@ int cels2x(
+@@ -513,7 +539,7 @@ int cels2x(
      ntheta = 0;
    }
  
@@ -475,16 +698,16 @@ Index: astropy-4.2/cextern/wcslib/C/cel.c
    celprj = &(cel->prj);
    if ((istat = celprj->prjs2x(celprj, nphi, ntheta, 1, sxy, phi, theta, x, y,
                                 stat))) {
-Index: astropy-4.2/cextern/wcslib/C/cel.h
+Index: astropy-4.2.1/cextern/wcslib/C/cel.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/cel.h
-+++ astropy-4.2/cextern/wcslib/C/cel.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/cel.h
++++ astropy-4.2.1/cextern/wcslib/C/cel.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -498,15 +721,59 @@ Index: astropy-4.2/cextern/wcslib/C/cel.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: cel.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: cel.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: cel.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
-@@ -382,50 +379,50 @@ extern "C" {
+@@ -51,7 +48,8 @@
+ *
+ * Routine celini() is provided to initialize the celprm struct with default
+ * values, celfree() reclaims any memory that may have been allocated to store
+-* an error message, and celprt() prints its contents.
++* an error message, celsize() computes its total size including allocated
++* memory, and celprt() prints its contents.
+ *
+ * celperr() prints the error message(s), if any, stored in a celprm struct and
+ * the prjprm struct that it contains.
+@@ -102,6 +100,33 @@
+ *                         1: Null celprm pointer passed.
+ *
+ *
++* celsize() - Compute the size of a celprm struct
++* -----------------------------------------------
++* celsize() computes the full size of a celprm struct, including allocated
++* memory.
++*
++* Given:
++*   cel       const struct celprm*
++*                       Celestial transformation parameters.
++*
++*                       If NULL, the base size of the struct and the allocated
++*                       size are both set to zero.
++*
++* Returned:
++*   sizes     int[2]    The first element is the base size of the struct as
++*                       returned by sizeof(struct celprm).  The second element
++*                       is the total allocated size, in bytes.  This figure
++*                       includes memory allocated for the constituent struct,
++*                       celprm::err.
++*
++*                       It is not an error for the struct not to have been set
++*                       up via celset().
++*
++* Function return value:
++*             int       Status return value:
++*                         0: Success.
++*
++*
+ * celprt() - Print routine for the celprm struct
+ * ----------------------------------------------
+ * celprt() prints the contents of a celprm struct using wcsprintf().  Mainly
+@@ -382,50 +407,50 @@ extern "C" {
  extern const char *cel_errmsg[];
  
  enum cel_errmsg_enum {
@@ -593,7 +860,16 @@ Index: astropy-4.2/cextern/wcslib/C/cel.h
  #define CELLEN (sizeof(struct celprm)/sizeof(int))
  
  
-@@ -450,7 +447,7 @@ int cels2x(struct celprm *cel, int nlng,
+@@ -433,6 +458,8 @@ int celini(struct celprm *cel);
+ 
+ int celfree(struct celprm *cel);
+ 
++int celsize(const struct celprm *cel, int sizes[2]);
++
+ int celprt(const struct celprm *cel);
+ 
+ int celperr(const struct celprm *cel, const char *prefix);
+@@ -450,7 +477,7 @@ int cels2x(struct celprm *cel, int nlng,
             int stat[]);
  
  
@@ -602,22 +878,22 @@ Index: astropy-4.2/cextern/wcslib/C/cel.h
  #define celini_errmsg cel_errmsg
  #define celprt_errmsg cel_errmsg
  #define celset_errmsg cel_errmsg
-@@ -461,4 +458,4 @@ int cels2x(struct celprm *cel, int nlng,
+@@ -461,4 +488,4 @@ int cels2x(struct celprm *cel, int nlng,
  }
  #endif
  
 -#endif /* WCSLIB_CEL */
 +#endif // WCSLIB_CEL
-Index: astropy-4.2/cextern/wcslib/C/dis.c
+Index: astropy-4.2.1/cextern/wcslib/C/dis.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/dis.c
-+++ astropy-4.2/cextern/wcslib/C/dis.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/dis.c
++++ astropy-4.2.1/cextern/wcslib/C/dis.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -631,7 +907,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: dis.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: dis.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: dis.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <math.h>
@@ -875,16 +1151,99 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      if (dis->axmap  && dis->axmap[0])  free(dis->axmap[0]);
      if (dis->offset && dis->offset[0]) free(dis->offset[0]);
      if (dis->scale  && dis->scale[0])  free(dis->scale[0]);
-@@ -430,7 +427,7 @@ int disfree(struct disprm *dis)
+@@ -430,7 +427,90 @@ int disfree(struct disprm *dis)
    return 0;
  }
  
 -/*--------------------------------------------------------------------------*/
++//----------------------------------------------------------------------------
++
++int dissize(const struct disprm *dis, int sizes[2])
++
++{
++  if (dis == 0x0) {
++    sizes[0] = sizes[1] = 0;
++    return DISERR_NULL_POINTER;
++  }
++
++  // Base size, in bytes.
++  sizes[0] = sizeof(struct disprm);
++
++  // Total size of allocated memory, in bytes.
++  sizes[1] = 0;
++
++  int exsizes[2];
++  int naxis = dis->naxis;
++
++  // disprm::dtype[].
++  sizes[1] += naxis * sizeof(char [72]);
++
++  // disprm::dp[].
++  sizes[1] += dis->ndpmax * sizeof(struct dpkey);
++
++  // disprm::maxdis[].
++  sizes[1] += naxis * sizeof(double);
++
++  // dis::err[].
++  wcserr_size(dis->err, exsizes);
++  sizes[1] += exsizes[0] + exsizes[1];
++
++  // The remaining arrays are allocated by disset().
++  if (dis->flag != DISSET) {
++    return DISERR_SUCCESS;
++  }
++
++  // dis::docorr[].
++  sizes[1] += naxis * sizeof(int *);
++
++  // dis::Nhat[].
++  sizes[1] += naxis * sizeof(int *);
++
++  // dis::axmap[][].
++  sizes[1] += naxis * sizeof(int *);
++  sizes[1] += naxis*naxis * sizeof(int);
++
++  // dis::offset[][].
++  sizes[1] += naxis * sizeof(double *);
++  sizes[1] += naxis*naxis * sizeof(double);
++
++  // dis::scale[][].
++  sizes[1] += naxis * sizeof(double *);
++  sizes[1] += naxis*naxis * sizeof(double);
++
++  // dis::iparm[][].
++  sizes[1] += naxis * sizeof(int *);
++  for (int j = 0; j < naxis; j++) {
++    if (dis->iparm[j]) {
++      sizes[1] += dis->iparm[j][I_NIPARM] * sizeof(int);
++    }
++  }
++
++  // dis::dparm[][].
++  sizes[1] += naxis * sizeof(double *);
++  for (int j = 0; j < naxis; j++) {
++    if (dis->dparm[j]) {
++      sizes[1] += dis->dparm[j][I_NDPARM] * sizeof(double);
++    }
++  }
++
++  // dis::disp2x[].
++  sizes[1] += naxis * sizeof(int (*)(DISP2X_ARGS));
++
++  // dis::disx2p[].
++  sizes[1] += naxis * sizeof(int (*)(DISX2P_ARGS));
++
++  // dis::tmpmem[].
++  sizes[1] += 5*naxis * sizeof(double);
++
++  return DISERR_SUCCESS;
++}
++
 +//----------------------------------------------------------------------------
  
  int disprt(const struct disprm *dis)
  
-@@ -450,7 +447,7 @@ int disprt(const struct disprm *dis)
+@@ -450,7 +530,7 @@ int disprt(const struct disprm *dis)
  
    wcsprintf("       flag: %d\n", dis->flag);
  
@@ -893,7 +1252,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    wcsprintf("      naxis: %d\n", naxis);
  
    WCSPRINTF_PTR("      dtype: ", dis->dtype, "\n");
-@@ -480,7 +477,7 @@ int disprt(const struct disprm *dis)
+@@ -480,7 +560,7 @@ int disprt(const struct disprm *dis)
  
    wcsprintf("     totdis:  %#- 11.5g\n", dis->totdis);
  
@@ -902,7 +1261,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    WCSPRINTF_PTR("     docorr: ", dis->docorr, "\n");
    wcsprintf("            ");
    for (j = 0; j < naxis; j++) {
-@@ -559,13 +556,13 @@ int disprt(const struct disprm *dis)
+@@ -559,13 +639,13 @@ int disprt(const struct disprm *dis)
    wcsprintf("    i_naxis: %d\n", dis->i_naxis);
    wcsprintf("       ndis: %d\n", dis->ndis);
  
@@ -918,7 +1277,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    WCSPRINTF_PTR("     disp2x: ", dis->disp2x, "\n");
    for (j = 0; j < naxis; j++) {
      wcsprintf("  disp2x[%d]: %s", j,
-@@ -601,7 +598,7 @@ int disprt(const struct disprm *dis)
+@@ -601,7 +681,7 @@ int disprt(const struct disprm *dis)
    }
    WCSPRINTF_PTR("     tmpmem: ", dis->tmpmem, "\n");
  
@@ -927,7 +1286,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    wcsprintf("     m_flag: %d\n", dis->m_flag);
    wcsprintf("    m_naxis: %d\n", dis->m_naxis);
    WCSPRINTF_PTR("    m_dtype: ", dis->m_dtype, "");
-@@ -617,7 +614,7 @@ int disprt(const struct disprm *dis)
+@@ -617,7 +697,7 @@ int disprt(const struct disprm *dis)
    return 0;
  }
  
@@ -936,7 +1295,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int disperr(const struct disprm *dis, const char *prefix)
  
-@@ -631,7 +628,7 @@ int disperr(const struct disprm *dis, co
+@@ -631,7 +711,7 @@ int disperr(const struct disprm *dis, co
    return 0;
  }
  
@@ -945,7 +1304,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int dishdo(struct disprm *dis)
  
-@@ -648,13 +645,13 @@ int dishdo(struct disprm *dis)
+@@ -648,13 +728,13 @@ int dishdo(struct disprm *dis)
    for (j = 0; j < dis->naxis; j++) {
      if (dis->iparm[j][I_DTYPE]) {
        if (dis->iparm[j][I_DTYPE] == DIS_TPD) {
@@ -962,7 +1321,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
          status = wcserr_set(WCSERR_SET(DISERR_BAD_PARAM),
            "Translation of %s to TPD is not possible", dis->dtype[j]);
        }
-@@ -664,7 +661,7 @@ int dishdo(struct disprm *dis)
+@@ -664,7 +744,7 @@ int dishdo(struct disprm *dis)
    return status;
  }
  
@@ -971,7 +1330,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int disset(struct disprm *dis)
  
-@@ -682,7 +679,7 @@ int disset(struct disprm *dis)
+@@ -682,7 +762,7 @@ int disset(struct disprm *dis)
    naxis = dis->naxis;
  
  
@@ -980,7 +1339,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (dis->ndp < 0) {
      return wcserr_set(WCSERR_SET(DISERR_BAD_PARAM),
        "disprm::ndp is negative (%d)", dis->ndp);
-@@ -697,7 +694,7 @@ int disset(struct disprm *dis)
+@@ -697,7 +777,7 @@ int disset(struct disprm *dis)
    }
  
    if (dis->ndp) {
@@ -989,7 +1348,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      if (dis->dp[0].field[1] == 'P') {
        dpq = "DPja";
      } else if (dis->dp[0].field[1] == 'Q') {
-@@ -714,26 +711,26 @@ int disset(struct disprm *dis)
+@@ -714,26 +794,26 @@ int disset(struct disprm *dis)
          "distortion");
      }
  
@@ -1022,7 +1381,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        free(dis->axmap[0]);
        free(dis->axmap);
        free(dis->offset[0]);
-@@ -760,7 +757,7 @@ int disset(struct disprm *dis)
+@@ -760,7 +840,7 @@ int disset(struct disprm *dis)
        return wcserr_set(DIS_ERRMSG(DISERR_MEMORY));
      }
  
@@ -1031,7 +1390,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      if ((dis->axmap = calloc(naxis, sizeof(int *))) == 0x0) {
        disfree(dis);
        return wcserr_set(DIS_ERRMSG(DISERR_MEMORY));
-@@ -775,7 +772,7 @@ int disset(struct disprm *dis)
+@@ -775,7 +855,7 @@ int disset(struct disprm *dis)
        dis->axmap[j] = dis->axmap[j-1] + naxis;
      }
  
@@ -1040,7 +1399,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      if ((dis->offset = calloc(naxis, sizeof(double *))) == 0x0) {
        disfree(dis);
        return wcserr_set(DIS_ERRMSG(DISERR_MEMORY));
-@@ -790,7 +787,7 @@ int disset(struct disprm *dis)
+@@ -790,7 +870,7 @@ int disset(struct disprm *dis)
        dis->offset[j] = dis->offset[j-1] + naxis;
      }
  
@@ -1049,7 +1408,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      if ((dis->scale = calloc(naxis, sizeof(double *))) == 0x0) {
        disfree(dis);
        return wcserr_set(DIS_ERRMSG(DISERR_MEMORY));
-@@ -833,7 +830,7 @@ int disset(struct disprm *dis)
+@@ -833,7 +913,7 @@ int disset(struct disprm *dis)
      dis->i_naxis = naxis;
    }
  
@@ -1058,7 +1417,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    for (j = 0; j < naxis; j++) {
      dis->docorr[j] = 1;
    }
-@@ -850,7 +847,7 @@ int disset(struct disprm *dis)
+@@ -850,7 +930,7 @@ int disset(struct disprm *dis)
      dis->scale[0][jhat] = 1.0;
    }
  
@@ -1067,7 +1426,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
    dis->i_naxis = naxis;
    dis->ndis    = 0;
-@@ -860,10 +857,10 @@ int disset(struct disprm *dis)
+@@ -860,10 +940,10 @@ int disset(struct disprm *dis)
    memset(dis->tmpmem, 0, naxis*sizeof(double));
  
  
@@ -1080,7 +1439,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      if (keyp->field[1] != dpq[1]) {
        return wcserr_set(WCSERR_SET(DISERR_BAD_PARAM),
          "disprm::dp appears to contain a mix of DPja and DQia keys");
-@@ -882,7 +879,7 @@ int disset(struct disprm *dis)
+@@ -882,7 +962,7 @@ int disset(struct disprm *dis)
      }
      fp++;
  
@@ -1089,7 +1448,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      j--;
  
      if (strncmp(fp, "DOCORR", 7) == 0) {
-@@ -908,7 +905,7 @@ int disset(struct disprm *dis)
+@@ -908,7 +988,7 @@ int disset(struct disprm *dis)
            dis->dtype[j], keyp->field, jhat);
        }
  
@@ -1098,7 +1457,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        dis->axmap[j][jhat-1] = dpkeyi(keyp) - 1;
  
      } else if (strncmp(fp, "OFFSET.", 7) == 0) {
-@@ -921,10 +918,10 @@ int disset(struct disprm *dis)
+@@ -921,10 +1001,10 @@ int disset(struct disprm *dis)
      }
    }
  
@@ -1111,7 +1470,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        keyp = dis->dp;
        for (idp = 0; idp < dis->ndp; idp++, keyp++) {
          if (keyp->j == j+1) {
-@@ -937,14 +934,14 @@ int disset(struct disprm *dis)
+@@ -937,14 +1017,14 @@ int disset(struct disprm *dis)
        continue;
      }
  
@@ -1128,7 +1487,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      Nhat = dis->Nhat[j];
      for (jhat = 0; jhat < Nhat; jhat++) {
        if (dis->axmap[j][jhat] == -1) {
-@@ -952,7 +949,7 @@ int disset(struct disprm *dis)
+@@ -952,7 +1032,7 @@ int disset(struct disprm *dis)
        }
      }
  
@@ -1137,7 +1496,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      Nhat = 0;
      for (jhat = 0; jhat < naxis; jhat++) {
        if (dis->axmap[j][jhat] != -1) Nhat = jhat+1;
-@@ -964,7 +961,7 @@ int disset(struct disprm *dis)
+@@ -964,7 +1044,7 @@ int disset(struct disprm *dis)
          dis->dtype[j], j+1);
      }
  
@@ -1146,7 +1505,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      for (jhat = 0; jhat < Nhat; jhat++) {
        for (k = 0; k < jhat; k++) {
          if (dis->axmap[j][jhat] == dis->axmap[j][k]) {
-@@ -977,11 +974,11 @@ int disset(struct disprm *dis)
+@@ -977,11 +1057,11 @@ int disset(struct disprm *dis)
    }
  
  
@@ -1160,7 +1519,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        continue;
      }
  
-@@ -990,47 +987,47 @@ int disset(struct disprm *dis)
+@@ -990,47 +1070,47 @@ int disset(struct disprm *dis)
          "Empty axis map for %s distortion on axis %d", dis->dtype[j], j+1);
      }
  
@@ -1221,7 +1580,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
          return status;
        }
  
-@@ -1048,7 +1045,7 @@ int disset(struct disprm *dis)
+@@ -1048,7 +1128,7 @@ int disset(struct disprm *dis)
    return 0;
  }
  
@@ -1230,7 +1589,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int disp2x(
    struct disprm *dis,
-@@ -1063,7 +1060,7 @@ int disp2x(
+@@ -1063,7 +1143,7 @@ int disp2x(
    struct wcserr **err;
  
  
@@ -1239,7 +1598,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (dis == 0x0) return DISERR_NULL_POINTER;
    err = &(dis->err);
  
-@@ -1074,7 +1071,7 @@ int disp2x(
+@@ -1074,7 +1154,7 @@ int disp2x(
    naxis = dis->naxis;
  
  
@@ -1248,7 +1607,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    tmpcrd = dis->tmpmem;
    for (j = 0; j < naxis; j++) {
      if (dis->disp2x[j]) {
-@@ -1093,10 +1090,10 @@ int disp2x(
+@@ -1093,10 +1173,10 @@ int disp2x(
        }
  
        if (dis->docorr[j]) {
@@ -1261,7 +1620,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
          discrd[j] = dtmp;
        }
  
-@@ -1108,9 +1105,9 @@ int disp2x(
+@@ -1108,9 +1188,9 @@ int disp2x(
    return 0;
  }
  
@@ -1274,7 +1633,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int disitermax(int itermax)
  
-@@ -1124,7 +1121,7 @@ int disitermax(int itermax)
+@@ -1124,7 +1204,7 @@ int disitermax(int itermax)
    return ITERMAX;
  }
  
@@ -1283,7 +1642,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int disx2p(
    struct disprm *dis,
-@@ -1142,28 +1139,28 @@ int disx2p(
+@@ -1142,28 +1222,28 @@ int disx2p(
    struct wcserr **err;
  
  
@@ -1321,7 +1680,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    for (j = 0; j < naxis; j++) {
      if (dis->disx2p[j]) {
        offset = dis->offset[j];
-@@ -1182,28 +1179,28 @@ int disx2p(
+@@ -1182,28 +1262,28 @@ int disx2p(
        }
  
        if (dis->docorr[j]) {
@@ -1355,7 +1714,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      convergence = 1;
      for (j = 0; j < naxis; j++) {
        delta[j] = discrd[j] - dcrd0[j];
-@@ -1211,22 +1208,22 @@ int disx2p(
+@@ -1211,22 +1291,22 @@ int disx2p(
        if (fabs(discrd[j]) < 1.0) {
          dd = delta[j];
        } else {
@@ -1383,7 +1742,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        delta[j] /= 2.0;
        if (fabs(delta[j]) < 1.0e-6) {
          if (delta[j] < 0.0) {
-@@ -1244,40 +1241,40 @@ int disx2p(
+@@ -1244,40 +1324,40 @@ int disx2p(
      }
  
      if (iter < itermax/2) {
@@ -1435,7 +1794,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
          rawcrd[j] += (discrd[j] - dcrd0[j]) *
                         (delta[j]/(dcrd1[j] - dcrd0[j]));
  
-@@ -1304,7 +1301,7 @@ int disx2p(
+@@ -1304,7 +1384,7 @@ int disx2p(
    return 0;
  }
  
@@ -1444,7 +1803,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int diswarp(
    struct disprm *dis,
-@@ -1328,7 +1325,7 @@ int diswarp(
+@@ -1328,7 +1408,7 @@ int diswarp(
    struct wcserr **err;
  
  
@@ -1453,7 +1812,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (dis == 0x0) return DISERR_NULL_POINTER;
    err = &(dis->err);
  
-@@ -1344,16 +1341,16 @@ int diswarp(
+@@ -1344,16 +1424,16 @@ int diswarp(
    if (avgtot) *avgtot = 0.0;
    if (rmstot) *rmstot = 0.0;
  
@@ -1473,7 +1832,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    for (j = 0; j < naxis; j++) {
      pixspan = pixtrc[j] - (pixblc ? pixblc[j] : 1.0);
  
-@@ -1370,7 +1367,7 @@ int diswarp(
+@@ -1370,7 +1450,7 @@ int diswarp(
      }
    }
  
@@ -1482,7 +1841,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if ((pix0 = calloc(2*naxis, sizeof(double))) == 0x0) {
      return wcserr_set(DIS_ERRMSG(DISERR_MEMORY));
    }
-@@ -1378,13 +1375,13 @@ int diswarp(
+@@ -1378,13 +1458,13 @@ int diswarp(
    pix1 = pix0 + naxis;
  
  
@@ -1498,7 +1857,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    for (j = 0; j < naxis; j++) {
      sumdis[j] = 0.0;
      ssqdis[j] = 0.0;
-@@ -1393,15 +1390,15 @@ int diswarp(
+@@ -1393,15 +1473,15 @@ int diswarp(
    ssqtot = 0.0;
  
  
@@ -1517,7 +1876,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      (*nsamp)++;
  
      dssq = 0.0;
-@@ -1427,7 +1424,7 @@ int diswarp(
+@@ -1427,7 +1507,7 @@ int diswarp(
        *maxtot = totdis;
      }
  
@@ -1526,7 +1885,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      for (j = 0; j < naxis; j++) {
        pix0[j] += pixinc[j];
        if (pix0[j] < pixend[j]) {
-@@ -1441,7 +1438,7 @@ int diswarp(
+@@ -1441,7 +1521,7 @@ int diswarp(
    }
  
  
@@ -1535,7 +1894,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    for (j = 0; j < naxis; j++) {
      ssqdis[j] /= *nsamp;
      sumdis[j] /= *nsamp;
-@@ -1461,7 +1458,7 @@ cleanup:
+@@ -1461,7 +1541,7 @@ cleanup:
    return status;
  }
  
@@ -1544,7 +1903,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int polyset(int j, struct disprm *dis)
  
-@@ -1476,7 +1473,7 @@ int polyset(int j, struct disprm *dis)
+@@ -1476,7 +1556,7 @@ int polyset(int j, struct disprm *dis)
    struct wcserr **err;
  
  
@@ -1553,7 +1912,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (dis == 0x0) return DISERR_NULL_POINTER;
    err = &(dis->err);
  
-@@ -1484,7 +1481,7 @@ int polyset(int j, struct disprm *dis)
+@@ -1484,7 +1564,7 @@ int polyset(int j, struct disprm *dis)
    sprintf(id, "Polynomial on axis %d", j+1);
  
  
@@ -1562,7 +1921,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    K = 0;
    M = 0;
    keyp = dis->dp;
-@@ -1520,31 +1517,31 @@ int polyset(int j, struct disprm *dis)
+@@ -1520,31 +1600,31 @@ int polyset(int j, struct disprm *dis)
    nTparm = 1 + nVar;
    ndparm = K*nKparm + M*nTparm;
  
@@ -1613,7 +1972,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if ((dis->iparm[j] = calloc(niparm, sizeof(int))) == 0x0) {
      return wcserr_set(DIS_ERRMSG(DISERR_MEMORY));
    }
-@@ -1553,12 +1550,12 @@ int polyset(int j, struct disprm *dis)
+@@ -1553,12 +1633,12 @@ int polyset(int j, struct disprm *dis)
      return wcserr_set(DIS_ERRMSG(DISERR_MEMORY));
    }
  
@@ -1628,7 +1987,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    iparm[I_DTYPE]  = DIS_POLYNOMIAL;
    iparm[I_NIPARM] = niparm;
    iparm[I_NDPARM] = ndparm;
-@@ -1579,7 +1576,7 @@ int polyset(int j, struct disprm *dis)
+@@ -1579,7 +1659,7 @@ int polyset(int j, struct disprm *dis)
    iparm[I_FLAGS]  = iparm[I_DPOFF]  + nVar;
    iparm[I_IPOW]   = iparm[I_FLAGS]  + M*nVar;
  
@@ -1637,7 +1996,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    dptr = dparm + (1 + Nhat);
    for (k = 0; k < K; k++) {
      for (jhat = 0; jhat <= Nhat; jhat++) {
-@@ -1588,24 +1585,24 @@ int polyset(int j, struct disprm *dis)
+@@ -1588,24 +1668,24 @@ int polyset(int j, struct disprm *dis)
      dptr += nKparm;
    }
  
@@ -1666,7 +2025,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        fp += 4;
        sscanf(fp, "%d", &k);
        if (k < 1 || K < k) {
-@@ -1633,7 +1630,7 @@ int polyset(int j, struct disprm *dis)
+@@ -1633,7 +1713,7 @@ int polyset(int j, struct disprm *dis)
        fp += 6;
        sscanf(fp, "%d", &jhat);
        if (jhat < 0 || naxis < jhat) {
@@ -1675,7 +2034,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
          return wcserr_set(WCSERR_SET(DISERR_BAD_PARAM),
          "Invalid axis number (%d) for %s: %s", jhat, id, keyp->field);
        }
-@@ -1642,7 +1639,7 @@ int polyset(int j, struct disprm *dis)
+@@ -1642,7 +1722,7 @@ int polyset(int j, struct disprm *dis)
        dparm[i] = dpkeyd(keyp);
  
      } else if (strncmp(fp, "TERM.", 5) == 0) {
@@ -1684,7 +2043,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        fp += 5;
        sscanf(fp, "%d", &m);
        if (m < 1 || M < m) {
-@@ -1661,7 +1658,7 @@ int polyset(int j, struct disprm *dis)
+@@ -1661,7 +1741,7 @@ int polyset(int j, struct disprm *dis)
          dparm[i] = dpkeyd(keyp);
  
        } else if (strncmp(fp, "VAR.", 4) == 0) {
@@ -1693,7 +2052,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
          fp += 4;
          sscanf(fp, "%d", &jhat);
          if (jhat < 1 || naxis < jhat) {
-@@ -1674,7 +1671,7 @@ int polyset(int j, struct disprm *dis)
+@@ -1674,7 +1754,7 @@ int polyset(int j, struct disprm *dis)
          dparm[i] = power;
  
        } else if (strncmp(fp, "AUX.", 4) == 0) {
@@ -1702,7 +2061,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
          fp += 4;
          sscanf(fp, "%d", &k);
          if (k < 1 || K < k) {
-@@ -1704,16 +1701,16 @@ int polyset(int j, struct disprm *dis)
+@@ -1704,16 +1784,16 @@ int polyset(int j, struct disprm *dis)
    }
  
  
@@ -1728,7 +2087,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      i = iparm[I_MAXPOW] + ivar;
      iparm[i] = 1;
    }
-@@ -1723,10 +1720,10 @@ int polyset(int j, struct disprm *dis)
+@@ -1723,10 +1803,10 @@ int polyset(int j, struct disprm *dis)
        i = iparm[I_DPOLY] + m*nTparm + 1 + ivar;
        power = dparm[i];
  
@@ -1741,7 +2100,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
          i = iparm[I_FLAGS] + m*nVar + ivar;
          if (ipow == 0) {
            iparm[i] = 3;
-@@ -1734,12 +1731,12 @@ int polyset(int j, struct disprm *dis)
+@@ -1734,12 +1814,12 @@ int polyset(int j, struct disprm *dis)
            iparm[i] = 1;
          }
  
@@ -1756,7 +2115,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        i = iparm[I_MAXPOW] + ivar;
        if (iparm[i] < abs(ipow)) {
          iparm[i] = abs(ipow);
-@@ -1747,10 +1744,10 @@ int polyset(int j, struct disprm *dis)
+@@ -1747,10 +1827,10 @@ int polyset(int j, struct disprm *dis)
      }
    }
  
@@ -1769,7 +2128,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      i = iparm[I_DPOFF] + ivar;
      iparm[i] = lendp + npow;
  
-@@ -1758,7 +1755,7 @@ int polyset(int j, struct disprm *dis)
+@@ -1758,7 +1838,7 @@ int polyset(int j, struct disprm *dis)
      npow += iparm[i];
    }
  
@@ -1778,7 +2137,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (npow) {
      lendp += npow;
      iparm[I_LENDP] = lendp;
-@@ -1767,12 +1764,12 @@ int polyset(int j, struct disprm *dis)
+@@ -1767,12 +1847,12 @@ int polyset(int j, struct disprm *dis)
      }
    }
  
@@ -1794,7 +2153,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (strcmp(dis->dtype[j], "Polynomial") == 0) {
      pol2tpd(j, dis);
    }
-@@ -1780,7 +1777,7 @@ int polyset(int j, struct disprm *dis)
+@@ -1780,7 +1860,7 @@ int polyset(int j, struct disprm *dis)
    return 0;
  }
  
@@ -1803,7 +2162,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int tpdset(int j, struct disprm *dis)
  
-@@ -1799,14 +1796,14 @@ int tpdset(int j, struct disprm *dis)
+@@ -1799,14 +1879,14 @@ int tpdset(int j, struct disprm *dis)
    sprintf(id, "TPD on axis %d", j+1);
  
  
@@ -1820,7 +2179,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    ncoeff[0] = 0;
    ncoeff[1] = 0;
    doaux     = 0;
-@@ -1823,7 +1820,7 @@ int tpdset(int j, struct disprm *dis)
+@@ -1823,7 +1903,7 @@ int tpdset(int j, struct disprm *dis)
          idis = 0;
  
        } else if (strncmp(fp, "REV.", 4) == 0) {
@@ -1829,7 +2188,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
          idis = 1;
  
        } else {
-@@ -1835,7 +1832,7 @@ int tpdset(int j, struct disprm *dis)
+@@ -1835,7 +1915,7 @@ int tpdset(int j, struct disprm *dis)
        if (0 <= k && k <= 59) {
          if (ncoeff[idis] < k+1) ncoeff[idis] = k+1;
  
@@ -1838,7 +2197,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
          if (k == 3 || k == 11 || k == 23 || k == 39 || k == 59) {
            doradial = 1;
          }
-@@ -1846,7 +1843,7 @@ int tpdset(int j, struct disprm *dis)
+@@ -1846,7 +1926,7 @@ int tpdset(int j, struct disprm *dis)
        }
  
      } else if (strncmp(fp, "AUX.", 4) == 0) {
@@ -1847,7 +2206,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        doaux = 1;
  
      } else if (strcmp(fp, "DOCORR") &&
-@@ -1864,43 +1861,43 @@ int tpdset(int j, struct disprm *dis)
+@@ -1864,43 +1944,43 @@ int tpdset(int j, struct disprm *dis)
    for (idis = 0; idis < 2; idis++) {
      if (ncoeff[idis] <= 4) {
        if (idis) {
@@ -1901,7 +2260,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        ncoeff[idis] = 60;
        distpd[idis] = tpd9;
      } else {
-@@ -1909,20 +1906,20 @@ int tpdset(int j, struct disprm *dis)
+@@ -1909,20 +1989,20 @@ int tpdset(int j, struct disprm *dis)
      }
    }
  
@@ -1930,7 +2289,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    niparm = I_NTPD;
    if ((dis->iparm[j] = calloc(niparm, sizeof(int))) == 0x0) {
      return wcserr_set(DIS_ERRMSG(DISERR_MEMORY));
-@@ -1930,28 +1927,28 @@ int tpdset(int j, struct disprm *dis)
+@@ -1930,28 +2010,28 @@ int tpdset(int j, struct disprm *dis)
  
    ndparm = (doaux?6:0) + ncoeff[0] + ncoeff[1];
  
@@ -1965,7 +2324,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (doaux) {
      dis->dparm[j][1] = 1.0;
      dis->dparm[j][5] = 1.0;
-@@ -1964,7 +1961,7 @@ int tpdset(int j, struct disprm *dis)
+@@ -1964,7 +2044,7 @@ int tpdset(int j, struct disprm *dis)
      fp = strchr(keyp->field, '.') + 1;
  
      if (strncmp(fp, "AUX.", 4) == 0) {
@@ -1974,7 +2333,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        fp += 4;
        sscanf(fp, "%d", &k);
        if (k < 1 || 2 < k) {
-@@ -2008,7 +2005,7 @@ int tpdset(int j, struct disprm *dis)
+@@ -2008,7 +2088,7 @@ int tpdset(int j, struct disprm *dis)
    return 0;
  }
  
@@ -1983,7 +2342,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int pol2tpd(int j, struct disprm *dis)
  
-@@ -2031,7 +2028,7 @@ int pol2tpd(int j, struct disprm *dis)
+@@ -2031,7 +2111,7 @@ int pol2tpd(int j, struct disprm *dis)
    double *dparm, *dpolp, *tpd_dparm;
    struct wcserr **err;
  
@@ -1992,7 +2351,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (dis == 0x0) return DISERR_NULL_POINTER;
    err = &(dis->err);
  
-@@ -2039,15 +2036,15 @@ int pol2tpd(int j, struct disprm *dis)
+@@ -2039,15 +2119,15 @@ int pol2tpd(int j, struct disprm *dis)
    dparm = dis->dparm[j];
  
  
@@ -2011,7 +2370,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      if (dparm[0] != 0.0) return -1;
      if (dparm[1] != 1.0) return -1;
      if (dparm[2] != 1.0) return -1;
-@@ -2056,14 +2053,14 @@ int pol2tpd(int j, struct disprm *dis)
+@@ -2056,14 +2136,14 @@ int pol2tpd(int j, struct disprm *dis)
      if (dparm[5] != 2.0) return -1;
    }
  
@@ -2028,7 +2387,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        if (*iflgp == 0)  return -1;
        if (*ipowp < 0)   return -1;
        deg += *ipowp;
-@@ -2071,20 +2068,20 @@ int pol2tpd(int j, struct disprm *dis)
+@@ -2071,20 +2151,20 @@ int pol2tpd(int j, struct disprm *dis)
        ipowp++;
      }
  
@@ -2053,7 +2412,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
          deg = *ipowp;
          if (!(deg%2))   return -1;
        }
-@@ -2096,7 +2093,7 @@ int pol2tpd(int j, struct disprm *dis)
+@@ -2096,7 +2176,7 @@ int pol2tpd(int j, struct disprm *dis)
    }
  
  
@@ -2062,7 +2421,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    ndparm = 0;
    if (degree == 1) {
      ndparm = 4;
-@@ -2127,32 +2124,32 @@ int pol2tpd(int j, struct disprm *dis)
+@@ -2127,32 +2207,32 @@ int pol2tpd(int j, struct disprm *dis)
      dis->disp2x[j] = tpd9;
    }
  
@@ -2102,7 +2461,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if ((tpd_dparm = calloc(ndparm, sizeof(double))) == 0x0) {
      return wcserr_set(DIS_ERRMSG(DISERR_MEMORY));
    }
-@@ -2161,7 +2158,7 @@ int pol2tpd(int j, struct disprm *dis)
+@@ -2161,7 +2241,7 @@ int pol2tpd(int j, struct disprm *dis)
    dpolp = dparm + iparm[I_DPOLY];
    for (m = 0; m < iparm[I_M]; m++) {
      if (K && ipowp[Nhat]) {
@@ -2111,7 +2470,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        switch (ipowp[Nhat]) {
        case 1:
          tpd_dparm[3]  = *dpolp;
-@@ -2181,7 +2178,7 @@ int pol2tpd(int j, struct disprm *dis)
+@@ -2181,7 +2261,7 @@ int pol2tpd(int j, struct disprm *dis)
        }
  
      } else {
@@ -2120,7 +2479,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        p[0] = p[1] = 0;
        for (jhat = 0; jhat < Nhat; jhat++) {
          p[jhat] = ipowp[jhat];
-@@ -2197,7 +2194,7 @@ int pol2tpd(int j, struct disprm *dis)
+@@ -2197,7 +2277,7 @@ int pol2tpd(int j, struct disprm *dis)
    }
  
  
@@ -2129,7 +2488,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    free(iparm);
    free(dparm);
    dis->iparm[j] = tpd_iparm;
-@@ -2206,7 +2203,7 @@ int pol2tpd(int j, struct disprm *dis)
+@@ -2206,7 +2286,7 @@ int pol2tpd(int j, struct disprm *dis)
    return 0;
  }
  
@@ -2138,7 +2497,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int tpvset(int j, struct disprm *dis)
  
-@@ -2219,14 +2216,15 @@ int tpvset(int j, struct disprm *dis)
+@@ -2219,14 +2299,15 @@ int tpvset(int j, struct disprm *dis)
    struct wcserr **err;
  
  
@@ -2157,7 +2516,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    dis->docorr[j] = 0;
  
    if (dis->Nhat[j] != 2) {
-@@ -2234,7 +2232,7 @@ int tpvset(int j, struct disprm *dis)
+@@ -2234,7 +2315,7 @@ int tpvset(int j, struct disprm *dis)
        "Axis map for %s must contain 2 entries, not %d", id, dis->Nhat[j]);
    }
  
@@ -2166,7 +2525,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    ndparm   = 0;
    doradial = 0;
    keyp = dis->dp;
-@@ -2248,7 +2246,7 @@ int tpvset(int j, struct disprm *dis)
+@@ -2248,7 +2329,7 @@ int tpvset(int j, struct disprm *dis)
        if (0 <= k && k <= 39) {
          if (ndparm < k+1) ndparm = k+1;
  
@@ -2175,7 +2534,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
          if (k == 3 || k == 11 || k == 23 || k == 39 || k == 59) {
            doradial = 1;
          }
-@@ -2267,67 +2265,67 @@ int tpvset(int j, struct disprm *dis)
+@@ -2267,67 +2348,67 @@ int tpvset(int j, struct disprm *dis)
      }
    }
  
@@ -2259,7 +2618,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if ((dis->dparm[j] = calloc(ndparm, sizeof(double))) == 0x0) {
      return wcserr_set(DIS_ERRMSG(DISERR_MEMORY));
    }
-@@ -2338,7 +2336,7 @@ int tpvset(int j, struct disprm *dis)
+@@ -2338,7 +2419,7 @@ int tpvset(int j, struct disprm *dis)
  
      fp = strchr(keyp->field, '.') + 1;
  
@@ -2268,7 +2627,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      if (strncmp(fp, "TPV.", 4) == 0) {
        sscanf(fp+4, "%d", &k);
        dis->dparm[j][k] = dpkeyd(keyp);
-@@ -2348,7 +2346,7 @@ int tpvset(int j, struct disprm *dis)
+@@ -2348,7 +2429,7 @@ int tpvset(int j, struct disprm *dis)
    return 0;
  }
  
@@ -2277,7 +2636,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int sipset(int j, struct disprm *dis)
  
-@@ -2373,15 +2371,15 @@ int sipset(int j, struct disprm *dis)
+@@ -2373,15 +2454,15 @@ int sipset(int j, struct disprm *dis)
    int (*(distpd[2]))(DISP2X_ARGS);
  
  
@@ -2296,7 +2655,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    dis->docorr[j] = 1;
  
    if (dis->Nhat[j] != 2) {
-@@ -2389,7 +2387,7 @@ int sipset(int j, struct disprm *dis)
+@@ -2389,7 +2470,7 @@ int sipset(int j, struct disprm *dis)
        "Axis map for %s must contain 2 entries, not %d", id, dis->Nhat[j]);
    }
  
@@ -2305,7 +2664,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    degree[0] =  1;
    degree[1] = -1;
    keyp = dis->dp;
-@@ -2404,7 +2402,7 @@ int sipset(int j, struct disprm *dis)
+@@ -2404,7 +2485,7 @@ int sipset(int j, struct disprm *dis)
          idis = 0;
  
        } else if (strncmp(fp, "REV.", 4) == 0) {
@@ -2314,7 +2673,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
          idis = 1;
  
        } else {
-@@ -2433,7 +2431,7 @@ int sipset(int j, struct disprm *dis)
+@@ -2433,7 +2514,7 @@ int sipset(int j, struct disprm *dis)
  
    if (degree[1] == 0 ) degree[1] = 1;
  
@@ -2323,7 +2682,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    distpd[0] = 0x0;
    distpd[1] = 0x0;
    for (idis = 0; idis < 2; idis++) {
-@@ -2468,13 +2466,13 @@ int sipset(int j, struct disprm *dis)
+@@ -2468,13 +2549,13 @@ int sipset(int j, struct disprm *dis)
      }
    }
  
@@ -2340,7 +2699,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    niparm = I_NTPD;
    if ((dis->iparm[j] = calloc(niparm, sizeof(int))) == 0x0) {
      return wcserr_set(DIS_ERRMSG(DISERR_MEMORY));
-@@ -2482,23 +2480,23 @@ int sipset(int j, struct disprm *dis)
+@@ -2482,23 +2563,23 @@ int sipset(int j, struct disprm *dis)
  
    ndparm = ncoeff[0] + ncoeff[1];
  
@@ -2369,7 +2728,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if ((dis->dparm[j] = calloc(ndparm, sizeof(double))) == 0x0) {
      return wcserr_set(DIS_ERRMSG(DISERR_MEMORY));
    }
-@@ -2519,7 +2517,7 @@ int sipset(int j, struct disprm *dis)
+@@ -2519,7 +2600,7 @@ int sipset(int j, struct disprm *dis)
  
        sscanf(fp+4, "%d_%d", &p, &q);
  
@@ -2378,7 +2737,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        idis += map[p][q];
  
        dis->dparm[j][idis] = dpkeyd(keyp);
-@@ -2530,7 +2528,7 @@ int sipset(int j, struct disprm *dis)
+@@ -2530,7 +2611,7 @@ int sipset(int j, struct disprm *dis)
    return 0;
  }
  
@@ -2387,7 +2746,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int dssset(int j, struct disprm *dis)
  
-@@ -2544,15 +2542,16 @@ int dssset(int j, struct disprm *dis)
+@@ -2544,15 +2625,16 @@ int dssset(int j, struct disprm *dis)
    struct wcserr **err;
  
  
@@ -2407,7 +2766,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    dis->docorr[j] = 0;
  
    if (dis->Nhat[j] != 2) {
-@@ -2560,15 +2559,15 @@ int dssset(int j, struct disprm *dis)
+@@ -2560,15 +2642,15 @@ int dssset(int j, struct disprm *dis)
        "Axis map for %s must contain 2 entries, not %d", id, dis->Nhat[j]);
    }
  
@@ -2426,7 +2785,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    niparm = I_NTPD;
    if ((dis->iparm[j] = calloc(niparm, sizeof(int))) == 0x0) {
      return wcserr_set(DIS_ERRMSG(DISERR_MEMORY));
-@@ -2576,29 +2575,29 @@ int dssset(int j, struct disprm *dis)
+@@ -2576,29 +2658,29 @@ int dssset(int j, struct disprm *dis)
  
    ndparm = 6 + ncoeff;
  
@@ -2463,7 +2822,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    A1 = A2 = A3 = 0.0;
    B1 = B2 = B3 = 0.0;
    keyp = dis->dp;
-@@ -2639,7 +2638,7 @@ int dssset(int j, struct disprm *dis)
+@@ -2639,7 +2721,7 @@ int dssset(int j, struct disprm *dis)
        "Coefficient scale for %s is zero.", id);
    }
  
@@ -2472,7 +2831,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    dparm = dis->dparm[j];
    if (j == 0) {
      dparm[0] =  X0;
-@@ -2649,7 +2648,7 @@ int dssset(int j, struct disprm *dis)
+@@ -2649,7 +2731,7 @@ int dssset(int j, struct disprm *dis)
      dparm[4] =  B2/S;
      dparm[5] =  A1/S;
  
@@ -2481,7 +2840,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      S *= -1.0;
  
    } else {
-@@ -2661,7 +2660,7 @@ int dssset(int j, struct disprm *dis)
+@@ -2661,7 +2743,7 @@ int dssset(int j, struct disprm *dis)
      dparm[5] = -A2/S;
    }
  
@@ -2490,7 +2849,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    dparm += 6;
    degree = 3;
    keyp = dis->dp;
-@@ -2671,13 +2670,13 @@ int dssset(int j, struct disprm *dis)
+@@ -2671,13 +2753,13 @@ int dssset(int j, struct disprm *dis)
      fp = strchr(keyp->field, '.') + 1;
  
      if (strncmp(fp, "DSS.AMD.", 8) == 0) {
@@ -2506,7 +2865,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        coeff /= S;
  
        if (m == 1) {
-@@ -2725,8 +2724,8 @@ int dssset(int j, struct disprm *dis)
+@@ -2725,8 +2807,8 @@ int dssset(int j, struct disprm *dis)
      }
    }
  
@@ -2517,7 +2876,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (degree == 3) {
      dis->iparm[j][I_TPDNCO] = 12;
      dis->disp2x[j] = tpd3;
-@@ -2735,7 +2734,7 @@ int dssset(int j, struct disprm *dis)
+@@ -2735,7 +2817,7 @@ int dssset(int j, struct disprm *dis)
    return 0;
  }
  
@@ -2526,7 +2885,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  #define CHEBYSHEV 1
  #define LEGENDRE  2
-@@ -2766,15 +2765,16 @@ int watset(int j, struct disprm *dis)
+@@ -2766,15 +2848,16 @@ int watset(int j, struct disprm *dis)
    struct wcserr **err;
  
  
@@ -2546,7 +2905,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    dis->docorr[j] = 1;
  
    if (dis->Nhat[j] != 2) {
-@@ -2782,7 +2782,7 @@ int watset(int j, struct disprm *dis)
+@@ -2782,7 +2865,7 @@ int watset(int j, struct disprm *dis)
        "Axis map for %s must contain 2 entries, not %d", id, dis->Nhat[j]);
    }
  
@@ -2555,7 +2914,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    degree = 1;
    kind = 0;
    xmin = xmax = 0.0;
-@@ -2836,51 +2836,51 @@ int watset(int j, struct disprm *dis)
+@@ -2836,51 +2919,51 @@ int watset(int j, struct disprm *dis)
  
    doaux = (kind == 1 || kind == 2);
  
@@ -2619,7 +2978,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    niparm = I_NTPD;
    if ((dis->iparm[j] = calloc(niparm, sizeof(int))) == 0x0) {
      return wcserr_set(DIS_ERRMSG(DISERR_MEMORY));
-@@ -2890,23 +2890,23 @@ int watset(int j, struct disprm *dis)
+@@ -2890,23 +2973,23 @@ int watset(int j, struct disprm *dis)
  
    ndparm = 6 + ncoeff;
  
@@ -2648,7 +3007,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if ((dis->dparm[j] = calloc(ndparm, sizeof(double))) == 0x0) {
      return wcserr_set(DIS_ERRMSG(DISERR_MEMORY));
    }
-@@ -2914,7 +2914,7 @@ int watset(int j, struct disprm *dis)
+@@ -2914,7 +2997,7 @@ int watset(int j, struct disprm *dis)
    dparm = dis->dparm[j];
  
  
@@ -2657,7 +3016,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (doaux) {
      x0 = (xmax + xmin)/2.0;
      dx = (xmax - xmin)/2.0;
-@@ -2942,7 +2942,7 @@ int watset(int j, struct disprm *dis)
+@@ -2942,7 +3025,7 @@ int watset(int j, struct disprm *dis)
    }
  
  
@@ -2666,7 +3025,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    keyp = dis->dp;
    for (idp = 0; idp < dis->ndp; idp++, keyp++) {
      if (keyp->j-1 != j) continue;
-@@ -2957,13 +2957,13 @@ int watset(int j, struct disprm *dis)
+@@ -2957,13 +3040,13 @@ int watset(int j, struct disprm *dis)
        sscanf(fp, "%d_%d", &m, &n);
  
        if (kind == MONOMIAL) {
@@ -2683,7 +3042,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
          coeff = dpkeyd(keyp);
  
          cheleg(kind, m, n, coeffm, coeffn);
-@@ -2984,9 +2984,9 @@ int watset(int j, struct disprm *dis)
+@@ -2984,9 +3067,9 @@ int watset(int j, struct disprm *dis)
    return 0;
  }
  
@@ -2696,7 +3055,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int cheleg(int kind, int m, int n, double coeffm[], double coeffn[])
  
-@@ -2996,7 +2996,7 @@ int cheleg(int kind, int m, int n, doubl
+@@ -2996,7 +3079,7 @@ int cheleg(int kind, int m, int n, doubl
  
    N = (m > n) ? m : n;
  
@@ -2705,7 +3064,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    coeff[0] = calloc(3*(N+1), sizeof(double));
    coeff[1] = coeff[0] + (N+1);
    coeff[2] = coeff[1] + (N+1);
-@@ -3011,7 +3011,7 @@ int cheleg(int kind, int m, int n, doubl
+@@ -3011,7 +3094,7 @@ int cheleg(int kind, int m, int n, doubl
        coeff[1][1] = 1.0;
  
      } else {
@@ -2714,7 +3073,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
        j1 = (j-1)%3;
        j2 = (j-2)%3;
  
-@@ -3038,7 +3038,7 @@ int cheleg(int kind, int m, int n, doubl
+@@ -3038,7 +3121,7 @@ int cheleg(int kind, int m, int n, doubl
    return 0;
  }
  
@@ -2723,7 +3082,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int dispoly(
    int dummy,
-@@ -3054,10 +3054,10 @@ int dispoly(
+@@ -3054,10 +3137,10 @@ int dispoly(
    const double *cptr, *dpolp, *pptr;
    double *aux, auxp0, *dvarpow, *dpowp, term, var;
  
@@ -2736,7 +3095,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    for (jhat = 0; jhat < Nhat; jhat++) {
      if (rawcrd[jhat] == 0.0) {
        *discrd = 0.0;
-@@ -3065,10 +3065,10 @@ int dispoly(
+@@ -3065,10 +3148,10 @@ int dispoly(
      }
    }
  
@@ -2749,7 +3108,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    for (k = 0; k < iparm[I_K]; k++) {
      cptr = dparm + k*iparm[I_NKPARM];
      pptr = cptr + (1+Nhat);
-@@ -3082,7 +3082,7 @@ int dispoly(
+@@ -3082,7 +3165,7 @@ int dispoly(
  
      aux[k] = pow(aux[k], auxp0);
  
@@ -2758,7 +3117,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
      if (aux[k] == 0.0) {
        *discrd = 0.0;
        return 0;
-@@ -3090,7 +3090,7 @@ int dispoly(
+@@ -3090,7 +3173,7 @@ int dispoly(
    }
  
  
@@ -2767,7 +3126,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    imaxpow = iparm + iparm[I_MAXPOW];
    dvarpow = (double *)(dparm + iparm[I_DVPOW]);
  
-@@ -3112,7 +3112,7 @@ int dispoly(
+@@ -3112,7 +3195,7 @@ int dispoly(
      }
    }
  
@@ -2776,7 +3135,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    *discrd = 0.0;
    iflgp = iparm + iparm[I_FLAGS];
    ipowp = iparm + iparm[I_IPOW];
-@@ -3120,25 +3120,25 @@ int dispoly(
+@@ -3120,25 +3203,25 @@ int dispoly(
    for (m = 0; m < iparm[I_M]; m++) {
      term = *(dpolp++);
  
@@ -2808,7 +3167,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
          term *= pow(dpowp[0], *dpolp);
        }
  
-@@ -3156,7 +3156,7 @@ int dispoly(
+@@ -3156,7 +3239,7 @@ int dispoly(
    return 0;
  }
  
@@ -2817,7 +3176,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int tpd1(
    int inverse,
-@@ -3176,7 +3176,7 @@ int tpd1(
+@@ -3176,7 +3259,7 @@ int tpd1(
    u = rawcrd[0];
    v = rawcrd[1];
  
@@ -2826,7 +3185,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDAUX]) {
      r = p[0] + p[1]*u + p[2]*v;
      v = p[3] + p[4]*u + p[5]*v;
-@@ -3186,14 +3186,14 @@ int tpd1(
+@@ -3186,14 +3269,14 @@ int tpd1(
  
    if (inverse) p += i[I_TPDNCO];
  
@@ -2843,7 +3202,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDRAD]) {
      s = u*u + v*v;
      r = sqrt(s);
-@@ -3204,7 +3204,7 @@ int tpd1(
+@@ -3204,7 +3287,7 @@ int tpd1(
    return 0;
  }
  
@@ -2852,7 +3211,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int tpd2(
    int inverse,
-@@ -3224,7 +3224,7 @@ int tpd2(
+@@ -3224,7 +3307,7 @@ int tpd2(
    u = rawcrd[0];
    v = rawcrd[1];
  
@@ -2861,7 +3220,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDAUX]) {
      r = p[0] + p[1]*u + p[2]*v;
      v = p[3] + p[4]*u + p[5]*v;
-@@ -3234,7 +3234,7 @@ int tpd2(
+@@ -3234,7 +3317,7 @@ int tpd2(
  
    if (inverse) p += i[I_TPDNCO];
  
@@ -2870,7 +3229,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    *discrd = p[0] + u*(p[1] + u*(p[4]));
  
    if (Nhat == 1) return 0;
-@@ -3243,7 +3243,7 @@ int tpd2(
+@@ -3243,7 +3326,7 @@ int tpd2(
        v*(p[2]  + v*(p[6]))
      + u*(p[5])*v;
  
@@ -2879,7 +3238,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDRAD]) {
      s = u*u + v*v;
      r = sqrt(s);
-@@ -3254,7 +3254,7 @@ int tpd2(
+@@ -3254,7 +3337,7 @@ int tpd2(
    return 0;
  }
  
@@ -2888,7 +3247,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int tpd3(
    int inverse,
-@@ -3274,7 +3274,7 @@ int tpd3(
+@@ -3274,7 +3357,7 @@ int tpd3(
    u = rawcrd[0];
    v = rawcrd[1];
  
@@ -2897,7 +3256,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDAUX]) {
      r = p[0] + p[1]*u + p[2]*v;
      v = p[3] + p[4]*u + p[5]*v;
-@@ -3284,7 +3284,7 @@ int tpd3(
+@@ -3284,7 +3367,7 @@ int tpd3(
  
    if (inverse) p += i[I_TPDNCO];
  
@@ -2906,7 +3265,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    *discrd = p[0] + u*(p[1] + u*(p[4] + u*(p[7])));
  
    if (Nhat == 1) return 0;
-@@ -3294,7 +3294,7 @@ int tpd3(
+@@ -3294,7 +3377,7 @@ int tpd3(
      + u*(p[5]  + v*(p[9])
      + u*(p[8]))*v;
  
@@ -2915,7 +3274,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDRAD]) {
      s = u*u + v*v;
      r = sqrt(s);
-@@ -3305,7 +3305,7 @@ int tpd3(
+@@ -3305,7 +3388,7 @@ int tpd3(
    return 0;
  }
  
@@ -2924,7 +3283,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int tpd4(
    int inverse,
-@@ -3325,7 +3325,7 @@ int tpd4(
+@@ -3325,7 +3408,7 @@ int tpd4(
    u = rawcrd[0];
    v = rawcrd[1];
  
@@ -2933,7 +3292,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDAUX]) {
      r = p[0] + p[1]*u + p[2]*v;
      v = p[3] + p[4]*u + p[5]*v;
-@@ -3335,7 +3335,7 @@ int tpd4(
+@@ -3335,7 +3418,7 @@ int tpd4(
  
    if (inverse) p += i[I_TPDNCO];
  
@@ -2942,7 +3301,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    *discrd = p[0] + u*(p[1] + u*(p[4] + u*(p[7] + u*(p[12]))));
  
    if (Nhat == 1) return 0;
-@@ -3346,7 +3346,7 @@ int tpd4(
+@@ -3346,7 +3429,7 @@ int tpd4(
      + u*(p[8]  + v*(p[14])
      + u*(p[13])))*v;
  
@@ -2951,7 +3310,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDRAD]) {
      s = u*u + v*v;
      r = sqrt(s);
-@@ -3357,7 +3357,7 @@ int tpd4(
+@@ -3357,7 +3440,7 @@ int tpd4(
    return 0;
  }
  
@@ -2960,7 +3319,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int tpd5(
    int inverse,
-@@ -3377,7 +3377,7 @@ int tpd5(
+@@ -3377,7 +3460,7 @@ int tpd5(
    u = rawcrd[0];
    v = rawcrd[1];
  
@@ -2969,7 +3328,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDAUX]) {
      r = p[0] + p[1]*u + p[2]*v;
      v = p[3] + p[4]*u + p[5]*v;
-@@ -3387,7 +3387,7 @@ int tpd5(
+@@ -3387,7 +3470,7 @@ int tpd5(
  
    if (inverse) p += i[I_TPDNCO];
  
@@ -2978,7 +3337,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    *discrd = p[0] + u*(p[1] + u*(p[4] + u*(p[7] + u*(p[12] + u*(p[17])))));
  
    if (Nhat == 1) return 0;
-@@ -3399,7 +3399,7 @@ int tpd5(
+@@ -3399,7 +3482,7 @@ int tpd5(
      + u*(p[13] + v*(p[19])
      + u*(p[18]))))*v;
  
@@ -2987,7 +3346,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDRAD]) {
      s = u*u + v*v;
      r = sqrt(s);
-@@ -3410,7 +3410,7 @@ int tpd5(
+@@ -3410,7 +3493,7 @@ int tpd5(
    return 0;
  }
  
@@ -2996,7 +3355,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int tpd6(
    int inverse,
-@@ -3430,7 +3430,7 @@ int tpd6(
+@@ -3430,7 +3513,7 @@ int tpd6(
    u = rawcrd[0];
    v = rawcrd[1];
  
@@ -3005,7 +3364,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDAUX]) {
      r = p[0] + p[1]*u + p[2]*v;
      v = p[3] + p[4]*u + p[5]*v;
-@@ -3440,7 +3440,7 @@ int tpd6(
+@@ -3440,7 +3523,7 @@ int tpd6(
  
    if (inverse) p += i[I_TPDNCO];
  
@@ -3014,7 +3373,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    *discrd = p[0] + u*(p[1] + u*(p[4] + u*(p[7] + u*(p[12] + u*(p[17] + u*(p[24]))))));
  
    if (Nhat == 1) return 0;
-@@ -3453,7 +3453,7 @@ int tpd6(
+@@ -3453,7 +3536,7 @@ int tpd6(
      + u*(p[18] + v*(p[26])
      + u*(p[25])))))*v;
  
@@ -3023,7 +3382,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDRAD]) {
      s = u*u + v*v;
      r = sqrt(s);
-@@ -3464,7 +3464,7 @@ int tpd6(
+@@ -3464,7 +3547,7 @@ int tpd6(
    return 0;
  }
  
@@ -3032,7 +3391,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int tpd7(
    int inverse,
-@@ -3484,7 +3484,7 @@ int tpd7(
+@@ -3484,7 +3567,7 @@ int tpd7(
    u = rawcrd[0];
    v = rawcrd[1];
  
@@ -3041,7 +3400,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDAUX]) {
      r = p[0] + p[1]*u + p[2]*v;
      v = p[3] + p[4]*u + p[5]*v;
-@@ -3494,7 +3494,7 @@ int tpd7(
+@@ -3494,7 +3577,7 @@ int tpd7(
  
    if (inverse) p += i[I_TPDNCO];
  
@@ -3050,7 +3409,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    *discrd = p[0] + u*(p[1] + u*(p[4] + u*(p[7] + u*(p[12] + u*(p[17] + u*(p[24] + u*(p[31])))))));
  
    if (Nhat == 1) return 0;
-@@ -3508,7 +3508,7 @@ int tpd7(
+@@ -3508,7 +3591,7 @@ int tpd7(
      + u*(p[25] + v*(p[33])
      + u*(p[32]))))))*v;
  
@@ -3059,7 +3418,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDRAD]) {
      s = u*u + v*v;
      r = sqrt(s);
-@@ -3519,7 +3519,7 @@ int tpd7(
+@@ -3519,7 +3602,7 @@ int tpd7(
    return 0;
  }
  
@@ -3068,7 +3427,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int tpd8(
    int inverse,
-@@ -3539,7 +3539,7 @@ int tpd8(
+@@ -3539,7 +3622,7 @@ int tpd8(
    u = rawcrd[0];
    v = rawcrd[1];
  
@@ -3077,7 +3436,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDAUX]) {
      r = p[0] + p[1]*u + p[2]*v;
      v = p[3] + p[4]*u + p[5]*v;
-@@ -3549,7 +3549,7 @@ int tpd8(
+@@ -3549,7 +3632,7 @@ int tpd8(
  
    if (inverse) p += i[I_TPDNCO];
  
@@ -3086,7 +3445,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    *discrd = p[0] + u*(p[1] + u*(p[4] + u*(p[7] + u*(p[12] + u*(p[17] + u*(p[24] + u*(p[31] + u*(p[40]))))))));
  
    if (Nhat == 1) return 0;
-@@ -3564,7 +3564,7 @@ int tpd8(
+@@ -3564,7 +3647,7 @@ int tpd8(
      + u*(p[32] + v*(p[42])
      + u*(p[41])))))))*v;
  
@@ -3095,7 +3454,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDRAD]) {
      s = u*u + v*v;
      r = sqrt(s);
-@@ -3575,7 +3575,7 @@ int tpd8(
+@@ -3575,7 +3658,7 @@ int tpd8(
    return 0;
  }
  
@@ -3104,7 +3463,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
  
  int tpd9(
    int inverse,
-@@ -3595,7 +3595,7 @@ int tpd9(
+@@ -3595,7 +3678,7 @@ int tpd9(
    u = rawcrd[0];
    v = rawcrd[1];
  
@@ -3113,7 +3472,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDAUX]) {
      r = p[0] + p[1]*u + p[2]*v;
      v = p[3] + p[4]*u + p[5]*v;
-@@ -3605,7 +3605,7 @@ int tpd9(
+@@ -3605,7 +3688,7 @@ int tpd9(
  
    if (inverse) p += i[I_TPDNCO];
  
@@ -3122,7 +3481,7 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    *discrd = p[0] + u*(p[1] + u*(p[4] + u*(p[7] + u*(p[12] + u*(p[17] + u*(p[24] + u*(p[31] + u*(p[40] + u*(p[49])))))))));
  
    if (Nhat == 1) return 0;
-@@ -3621,7 +3621,7 @@ int tpd9(
+@@ -3621,7 +3704,7 @@ int tpd9(
      + u*(p[41] + v*(p[51])
      + u*(p[50]))))))))*v;
  
@@ -3131,16 +3490,16 @@ Index: astropy-4.2/cextern/wcslib/C/dis.c
    if (i[I_TPDRAD]) {
      s = u*u + v*v;
      r = sqrt(s);
-Index: astropy-4.2/cextern/wcslib/C/dis.h
+Index: astropy-4.2.1/cextern/wcslib/C/dis.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/dis.h
-+++ astropy-4.2/cextern/wcslib/C/dis.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/dis.h
++++ astropy-4.2.1/cextern/wcslib/C/dis.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -3154,11 +3513,11 @@ Index: astropy-4.2/cextern/wcslib/C/dis.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: dis.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: dis.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: dis.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
@@ -3211,7 +3570,53 @@ Index: astropy-4.2/cextern/wcslib/C/dis.h
  * Summary of the dis routines:
  * ----------------------------
  * These routines apply the distortion functions defined by the extension to
-@@ -1010,88 +1028,88 @@ extern "C" {
+@@ -319,7 +337,8 @@
+ * dpfill(), dpkeyi(), and dpkeyd() are provided to manage the dpkey struct.
+ *
+ * disndp(), disini(), disinit(), discpy(), and disfree() are provided to
+-* manage the disprm struct, and another, disprt(), prints its contents.
++* manage the disprm struct, dissize() computes its total size including
++* allocated memory, and disprt() prints its contents.
+ *
+ * disperr() prints the error message(s) (if any) stored in a disprm struct.
+ *
+@@ -545,6 +564,35 @@
+ *                         1: Null disprm pointer passed.
+ *
+ *
++* dissize() - Compute the size of a disprm struct
++* -----------------------------------------------
++* dissize() computes the full size of a disprm struct, including allocated
++* memory.
++*
++* Given:
++*   dis       const struct disprm*
++*                       Distortion function parameters.
++*
++*                       If NULL, the base size of the struct and the allocated
++*                       size are both set to zero.
++*
++* Returned:
++*   sizes     int[2]    The first element is the base size of the struct as
++*                       returned by sizeof(struct disprm).  The second element
++*                       is the total allocated size, in bytes, assuming that
++*                       the allocation was done by disini().  This figure
++*                       includes memory allocated for members of constituent
++*                       structs, such as disprm::dp.
++*
++*                       It is not an error for the struct not to have been set
++*                       up via tabset(), which normally results in additional
++*                       memory allocation. 
++*
++* Function return value:
++*             int       Status return value:
++*                         0: Success.
++*
++*
+ * disprt() - Print routine for the disprm struct
+ * ----------------------------------------------
+ * disprt() prints the contents of a disprm struct using wcsprintf().  Mainly
+@@ -1010,88 +1058,88 @@ extern "C" {
  extern const char *dis_errmsg[];
  
  enum dis_errmsg_enum {
@@ -3354,22 +3759,31 @@ Index: astropy-4.2/cextern/wcslib/C/dis.h
  #define DISLEN (sizeof(struct disprm)/sizeof(int))
  
  
-@@ -1134,4 +1152,4 @@ int diswarp(struct disprm *dis, const do
+@@ -1112,6 +1160,8 @@ int discpy(int alloc, const struct dispr
+ 
+ int disfree(struct disprm *dis);
+ 
++int dissize(const struct disprm *dis, int sizes[2]);
++
+ int disprt(const struct disprm *dis);
+ 
+ int disperr(const struct disprm *dis, const char *prefix);
+@@ -1134,4 +1184,4 @@ int diswarp(struct disprm *dis, const do
  }
  #endif
  
 -#endif /* WCSLIB_DIS */
 +#endif // WCSLIB_DIS
-Index: astropy-4.2/cextern/wcslib/C/fitshdr.h
+Index: astropy-4.2.1/cextern/wcslib/C/fitshdr.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/fitshdr.h
-+++ astropy-4.2/cextern/wcslib/C/fitshdr.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/fitshdr.h
++++ astropy-4.2.1/cextern/wcslib/C/fitshdr.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -3383,15 +3797,23 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: fitshdr.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: fitshdr.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: fitshdr.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
-@@ -384,17 +381,17 @@ extern "C" {
+@@ -96,6 +93,7 @@
+ *                         1: Null fitskey pointer passed.
+ *                         2: Memory allocation failed.
+ *                         3: Fatal error returned by Flex parser.
++*                         4: Unrecognised data type.
+ *
+ * Notes:
+ *   1: Keyword parsing is done in accordance with the syntax defined by
+@@ -384,17 +382,18 @@ extern "C" {
  #define FITSHDR_KEYVALUE 0x02
  #define FITSHDR_COMMENT  0x04
  #define FITSHDR_KEYREC   0x08
@@ -3410,11 +3832,12 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.h
 +  FITSHDRERR_SUCCESS      = 0,	// Success.
 +  FITSHDRERR_NULL_POINTER = 1,	// Null fitskey pointer passed.
 +  FITSHDRERR_MEMORY       = 2,	// Memory allocation failed.
-+  FITSHDRERR_FLEX_PARSER  = 3	// Fatal error returned by Flex parser.
++  FITSHDRERR_FLEX_PARSER  = 3,	// Fatal error returned by Flex parser.
++  FITSHDRERR_DATA_TYPE    = 4 	// Unrecognised data type.
  };
  
  #ifdef WCSLIB_INT64
-@@ -404,38 +401,38 @@ enum fitshdr_errmsg_enum {
+@@ -404,38 +403,38 @@ enum fitshdr_errmsg_enum {
  #endif
  
  
@@ -3475,22 +3898,22 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.h
  #define KEYLEN (sizeof(struct fitskey)/sizeof(int))
  
  
-@@ -447,4 +444,4 @@ int fitshdr(const char header[], int nke
+@@ -447,4 +446,4 @@ int fitshdr(const char header[], int nke
  }
  #endif
  
 -#endif /* WCSLIB_FITSHDR */
 +#endif // WCSLIB_FITSHDR
-Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
+Index: astropy-4.2.1/cextern/wcslib/C/fitshdr.l
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/fitshdr.l
-+++ astropy-4.2/cextern/wcslib/C/fitshdr.l
+--- astropy-4.2.1.orig/cextern/wcslib/C/fitshdr.l
++++ astropy-4.2.1/cextern/wcslib/C/fitshdr.l
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -3504,74 +3927,186 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: fitshdr.l,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: fitshdr.l,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: fitshdr.l,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
  * fitshdr.l is a Flex description file containing a lexical scanner
-@@ -88,7 +85,7 @@ static int fitshdr_scanner(const char he
-                            struct fitskeyid keyids[], int *nreject, \
-                            struct fitskey **keys, yyscan_t yyscanner);
+@@ -44,6 +41,7 @@
+ %option outfile="fitshdr.c"
+ %option prefix="fitshdr"
+ %option reentrant
++%option extra-type="struct fitshdr_extra *"
  
+ /* Keywords. */
+ KEYCHR	[-_A-Z0-9]
+@@ -84,35 +82,15 @@ UNITSTR \[[-+*/^(). 0-9a-zA-Z]+\]
+ #include "fitshdr.h"
+ #include "wcsutil.h"
+ 
+-static int fitshdr_scanner(const char header[], int nkeyrec, int nkeyids, \
+-                           struct fitskeyid keyids[], int *nreject, \
+-                           struct fitskey **keys, yyscan_t yyscanner);
+-
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
- 
- int fitshdr(
-   const char header[],
-@@ -112,7 +109,7 @@ int fitshdr(
-   return status;
- }
- 
+-
+-int fitshdr(
+-  const char header[],
+-  int nkeyrec,
+-  int nkeyids,
+-  struct fitskeyid keyids[],
+-  int *nreject,
+-  struct fitskey **keys)
+-
+-{
+-  int status;
+-  yyscan_t yyscanner;
+-  int yylex_init(yyscan_t *yyscanner);
+-  int yylex_destroy(yyscan_t yyscanner);
+-
+-  yylex_init(&yyscanner);
+-  status = fitshdr_scanner(header, nkeyrec, nkeyids, keyids, nreject,
+-                           keys, yyscanner);
+-  yylex_destroy(yyscanner);
+-
+-  return status;
+-}
+-
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
++// User data associated with yyscanner.
++struct fitshdr_extra {
++  // Values passed to YY_INPUT.
++  const char *hdr;
++  int  nkeyrec;
++
++  // Used in preempting the call to exit() by yy_fatal_error().
++  jmp_buf abort_jmp_env;
++};
  
  #define YY_DECL int fitshdr_scanner(const char header[], int nkeyrec, \
    int nkeyids, struct fitskeyid keyids[], int *nreject, \
-@@ -131,15 +128,15 @@ int fitshdr(
+@@ -120,26 +98,25 @@ int fitshdr(
+ 
+ #define YY_INPUT(inbuff, count, bufsize) \
+ 	{ \
+-	  if (fitshdr_nkeyrec) { \
+-	    strncpy(inbuff, fitshdr_hdr, 80); \
++	  if (yyextra->nkeyrec) { \
++	    strncpy(inbuff, yyextra->hdr, 80); \
+ 	    inbuff[80] = '\n'; \
+-	    fitshdr_hdr += 80; \
+-	    fitshdr_nkeyrec--; \
++	    yyextra->hdr += 80; \
++	    yyextra->nkeyrec--; \
+ 	    count = 81; \
+ 	  } else { \
+ 	    count = YY_NULL; \
  	  } \
  	}
  
 -/* These global variables are required by YY_INPUT. */
-+// These global variables are required by YY_INPUT.
- const char *fitshdr_hdr;
- int  fitshdr_nkeyrec;
- 
+-const char *fitshdr_hdr;
+-int  fitshdr_nkeyrec;
+-
 -/* Used in preempting the call to exit() by yy_fatal_error(). */
-+// Used in preempting the call to exit() by yy_fatal_error().
- jmp_buf fitshdr_abort_jmp_env;
- #define exit(status) longjmp(fitshdr_abort_jmp_env, status)
+-jmp_buf fitshdr_abort_jmp_env;
+-#define exit(status) longjmp(fitshdr_abort_jmp_env, status)
++// Preempt the call to exit() by yy_fatal_error().
++#define exit(status) longjmp(yyextra->abort_jmp_env, status);
  
 -/* Map status return value to message. */
++// Internal helper functions.
++static YY_DECL;
++static void nullfill(char cptr[], int len);
++
 +// Map status return value to message.
  const char *fitshdr_errmsg[] = {
     "Success",
     "Null fitskey pointer-pointer passed",
-@@ -166,13 +163,13 @@ const char *fitshdr_errmsg[] = {
- 	  return 1;
+@@ -149,50 +126,65 @@ const char *fitshdr_errmsg[] = {
+ %}
+ 
+ %%
+-	char *cptr, ctmp[72];
+-	int  blank, continuation, end, j, k, keyno;
+-	double dtmp;
+-	struct fitskey *kptr;
+-	struct fitskeyid *iptr;
+-	void nullfill(char cptr[], int len);
+-	
+-	fitshdr_hdr = header;
+-	fitshdr_nkeyrec = nkeyrec;
+-	
+-	*nreject = 0;
+-	keyno = 0;
++	char ctmp[72];
+ 	
+ 	if (keys == 0x0) {
+-	  return 1;
++	  return FITSHDRERR_NULL_POINTER;
  	}
  	
 -	/* Allocate memory for the required number of fitskey structs. */
 -	/* Recall that calloc() initializes allocated memory to zero.  */
 +	// Allocate memory for the required number of fitskey structs.
 +	// Recall that calloc() initializes allocated memory to zero.
++	struct fitskey *kptr;
  	if (!(kptr = *keys = calloc(nkeyrec, sizeof(struct fitskey)))) {
- 	  return 2;
+-	  return 2;
++	  return FITSHDRERR_MEMORY;
  	}
  	
 -	/* Initialize keyids[]. */
+-	iptr = keyids;
+-	for (j = 0; j < nkeyids; j++, iptr++) {
++	// Initialize returned values.
++	*nreject = 0;
++	
 +	// Initialize keyids[].
- 	iptr = keyids;
- 	for (j = 0; j < nkeyids; j++, iptr++) {
++	struct fitskeyid *iptr = keyids;
++	for (int j = 0; j < nkeyids; j++, iptr++) {
  	  iptr->count  = 0;
-@@ -184,7 +181,7 @@ const char *fitshdr_errmsg[] = {
- 	continuation = 0;
- 	end = 0;
- 	
--	/* Return here via longjmp() invoked by yy_fatal_error(). */
-+	// Return here via longjmp() invoked by yy_fatal_error().
- 	if (setjmp(fitshdr_abort_jmp_env)) {
- 	  return 3;
+ 	  iptr->idx[0] = -1;
+ 	  iptr->idx[1] = -1;
  	}
-@@ -192,7 +189,7 @@ const char *fitshdr_errmsg[] = {
++
++	int keyno = 0;
++	
++	int blank = 0;
++	int continuation = 0;
++	int end = 0;
++	
++	#ifdef WCSLIB_INT64
++	  #define asString(S) stringize(S)
++	  #define stringize(S) #S
++	
++	  const char *int64fmt;
++	  if (strcmp(asString(WCSLIB_INT64), "long long int") == 0) {
++	    int64fmt = "%lld";
++	  } else if (strcmp(asString(WCSLIB_INT64), "long int") == 0) {
++	    int64fmt = "%ld";
++	  } else if (strcmp(asString(WCSLIB_INT64), "int") == 0) {
++	    int64fmt = "%d";
++	  } else {
++	    return FITSHDRERR_DATA_TYPE;
++	  }
++	#endif
++	
++	// User data associated with yyscanner.
++	yyextra->hdr = header;
++	yyextra->nkeyrec = nkeyrec;
+ 	
+-	blank = 0;
+-	continuation = 0;
+-	end = 0;
+-	
+-	/* Return here via longjmp() invoked by yy_fatal_error(). */
+-	if (setjmp(fitshdr_abort_jmp_env)) {
+-	  return 3;
++	// Return here via longjmp() invoked by yy_fatal_error().
++	if (setjmp(yyextra->abort_jmp_env)) {
++	  return FITSHDRERR_FLEX_PARSER;
+ 	}
+ 	
  	BEGIN(INITIAL);
  
  ^" "{80} {
@@ -3580,7 +4115,7 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
  	  strncpy(kptr->keyword, yytext, 8);
  	  yyless(0);
  	  blank = 1;
-@@ -211,14 +208,14 @@ const char *fitshdr_errmsg[] = {
+@@ -211,14 +203,14 @@ const char *fitshdr_errmsg[] = {
  	}
  
  ^END" "{5}=" "+ {
@@ -3597,7 +4132,7 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
  	  strncpy(kptr->keyword, yytext, 8);
  	  kptr->status |= FITSHDR_KEYREC;
  	  BEGIN(COMMENT);
-@@ -230,57 +227,57 @@ const char *fitshdr_errmsg[] = {
+@@ -230,57 +222,58 @@ const char *fitshdr_errmsg[] = {
  	}
  
  ^CONTINUE"  "+{STRING} {
@@ -3608,6 +4143,7 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
  	  if (keyno > 0 && (kptr-1)->type%10 == 8) {
 -	    /* Put back the string keyvalue. */
 +	    // Put back the string keyvalue.
++	    int k;
  	    for (k = 10; yytext[k] != '\''; k++);
  	    yyless(k);
  	    continuation = 1;
@@ -3664,12 +4200,13 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
  	  kptr->type = 2;
  	  if (sscanf(yytext, "%d", &(kptr->keyvalue.i)) < 1) {
  	    kptr->status |= FITSHDR_KEYVALUE;
-@@ -291,13 +288,13 @@ const char *fitshdr_errmsg[] = {
+@@ -291,13 +284,14 @@ const char *fitshdr_errmsg[] = {
  	}
  
  <VALUE>{INT64} {
 -	  /* 64-bit signed integer keyvalue (up to 18 digits). */
 +	  // 64-bit signed integer keyvalue (up to 18 digits).
++	  double dtmp;
  	  if (wcsutil_str2double(yytext, &dtmp)) {
  	    kptr->status |= FITSHDR_KEYVALUE;
  	    BEGIN(ERROR);
@@ -3680,7 +4217,7 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
  	    kptr->type = 2;
  	    if (sscanf(yytext, "%d", &(kptr->keyvalue.i)) < 1) {
  	      kptr->status |= FITSHDR_KEYVALUE;
-@@ -305,16 +302,16 @@ const char *fitshdr_errmsg[] = {
+@@ -305,16 +299,16 @@ const char *fitshdr_errmsg[] = {
  	    }
  	
  	  } else {
@@ -3689,8 +4226,9 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
  	    kptr->type = 3;
  	    #ifdef WCSLIB_INT64
 -	      /* Native 64-bit integer is available. */
+-	      if (sscanf(yytext, "%lld", &(kptr->keyvalue.k)) < 1) {
 +	      // Native 64-bit integer is available.
- 	      if (sscanf(yytext, "%lld", &(kptr->keyvalue.k)) < 1) {
++	      if (sscanf(yytext, int64fmt, &(kptr->keyvalue.k)) < 1) {
  	        kptr->status |= FITSHDR_KEYVALUE;
  	        BEGIN(ERROR);
  	      }
@@ -3700,7 +4238,7 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
  	      kptr->keyvalue.k[2] = 0;
  	
  	      sprintf(ctmp, "%%%dd%%9d", yyleng-9);
-@@ -332,12 +329,12 @@ const char *fitshdr_errmsg[] = {
+@@ -332,12 +326,12 @@ const char *fitshdr_errmsg[] = {
  	}
  
  <VALUE>{INTVL} {
@@ -3708,14 +4246,15 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
 +	  // Very long integer keyvalue (and 19-digit int64).
  	  kptr->type = 4;
  	  strcpy(ctmp, yytext);
- 	  k = yyleng;
+-	  k = yyleng;
++	  int j, k = yyleng;
  	  for (j = 0; j < 8; j++) {
 -	    /* Read it backwards. */
 +	    // Read it backwards.
  	    k -= 9;
  	    if (k < 0) k = 0;
  	    if (sscanf(ctmp+k, "%d", kptr->keyvalue.l+j) < 1) {
-@@ -352,7 +349,7 @@ const char *fitshdr_errmsg[] = {
+@@ -352,7 +346,7 @@ const char *fitshdr_errmsg[] = {
  	    ctmp[k] = '\0';
  	  }
  	
@@ -3724,16 +4263,19 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
  	  if (j == 2 && abs(kptr->keyvalue.l[2]) <=  9 &&
  	                abs(kptr->keyvalue.l[1]) <=  223372036 &&
  	                    kptr->keyvalue.l[0]  <=  854775807 &&
-@@ -360,7 +357,7 @@ const char *fitshdr_errmsg[] = {
+@@ -360,9 +354,9 @@ const char *fitshdr_errmsg[] = {
  	    kptr->type = 3;
  	
  	    #ifdef WCSLIB_INT64
 -	      /* Native 64-bit integer is available. */
 +	      // Native 64-bit integer is available.
  	      kptr->keyvalue.l[2] = 0;
- 	      if (sscanf(yytext, "%lld", &(kptr->keyvalue.k)) < 1) {
+-	      if (sscanf(yytext, "%lld", &(kptr->keyvalue.k)) < 1) {
++	      if (sscanf(yytext, int64fmt, &(kptr->keyvalue.k)) < 1) {
  	        kptr->status |= FITSHDR_KEYVALUE;
-@@ -373,7 +370,7 @@ const char *fitshdr_errmsg[] = {
+ 	        BEGIN(ERROR);
+ 	      }
+@@ -373,7 +367,7 @@ const char *fitshdr_errmsg[] = {
  	}
  
  <VALUE>{FLOAT} {
@@ -3742,7 +4284,7 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
  	  kptr->type = 5;
  	  if (wcsutil_str2double(yytext, &(kptr->keyvalue.f))) {
  	    kptr->status |= FITSHDR_KEYVALUE;
-@@ -384,7 +381,7 @@ const char *fitshdr_errmsg[] = {
+@@ -384,7 +378,7 @@ const char *fitshdr_errmsg[] = {
  	}
  
  <VALUE>{ICOMPLX} {
@@ -3751,7 +4293,7 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
  	  kptr->type = 6;
  	  if (sscanf(yytext, "(%lf,%lf)", kptr->keyvalue.c,
  	      kptr->keyvalue.c+1) < 2) {
-@@ -396,7 +393,7 @@ const char *fitshdr_errmsg[] = {
+@@ -396,9 +390,11 @@ const char *fitshdr_errmsg[] = {
  	}
  
  <VALUE>{FCOMPLX} {
@@ -3759,23 +4301,32 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
 +	  // Floating point complex keyvalue.
  	  kptr->type = 7;
  	
++	  char *cptr;
++	  int k;
  	  for (cptr = ctmp, k = 1; yytext[k] != ','; cptr++, k++) {
-@@ -423,12 +420,12 @@ const char *fitshdr_errmsg[] = {
+ 	    *cptr = yytext[k];
+ 	  }
+@@ -423,14 +419,14 @@ const char *fitshdr_errmsg[] = {
  	}
  
  <VALUE>{STRING} {
 -	  /* String keyvalue. */
 +	  // String keyvalue.
  	  kptr->type = 8;
- 	  cptr = kptr->keyvalue.s;
+-	  cptr = kptr->keyvalue.s;
++	  char *cptr = kptr->keyvalue.s;
  	  strcpy(cptr, yytext+1);
  	
 -	  /* Squeeze out repeated quotes. */
+-	  k = 0;
+-	  for (j = 0; j < 72; j++) {
 +	  // Squeeze out repeated quotes.
- 	  k = 0;
- 	  for (j = 0; j < 72; j++) {
++	  int k = 0;
++	  for (int j = 0; j < 72; j++) {
  	    if (k < j) {
-@@ -446,7 +443,7 @@ const char *fitshdr_errmsg[] = {
+ 	      cptr[k] = cptr[j];
+ 	    }
+@@ -446,7 +442,7 @@ const char *fitshdr_errmsg[] = {
  	  }
  	
  	  if (*cptr) {
@@ -3784,7 +4335,7 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
  	    nullfill(cptr+1, 71);
  	  } else {
  	    nullfill(cptr, 72);
-@@ -478,7 +475,7 @@ const char *fitshdr_errmsg[] = {
+@@ -478,7 +474,7 @@ const char *fitshdr_errmsg[] = {
  	}
  
  <INLINE>. {
@@ -3793,7 +4344,16 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
  	  kptr->status |= FITSHDR_COMMENT;
  	  kptr->type = 0;
  	  BEGIN(ERROR);
-@@ -512,14 +509,14 @@ const char *fitshdr_errmsg[] = {
+@@ -504,7 +500,7 @@ const char *fitshdr_errmsg[] = {
+ <ERROR>.* {
+ 	  if (!continuation) kptr->type = -abs(kptr->type);
+ 	
+-	  sprintf(kptr->comment, "%.80s", fitshdr_hdr-80);
++	  sprintf(kptr->comment, "%.80s", yyextra->hdr-80);
+ 	  kptr->comment[80] = '\0';
+ 	  nullfill(kptr->comment+80, 4);
+ 	
+@@ -512,18 +508,19 @@ const char *fitshdr_errmsg[] = {
  	}
  
  <FLUSH>.*\n {
@@ -3810,7 +4370,14 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
 +	  // Do indexing.
  	  iptr = keyids;
  	  kptr->keyid = -1;
- 	  for (j = 0; j < nkeyids; j++, iptr++) {
+-	  for (j = 0; j < nkeyids; j++, iptr++) {
+-	    cptr = iptr->name;
++	  for (int j = 0; j < nkeyids; j++, iptr++) {
++	    int k;
++	    char *cptr = iptr->name;
+ 	    cptr[8] = '\0';
+ 	    nullfill(cptr, 12);
+ 	    for (k = 0; k < 8; k++, cptr++) {
 @@ -531,7 +528,7 @@ const char *fitshdr_errmsg[] = {
  	    }
  	
@@ -3820,7 +4387,7 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
  	      iptr->count++;
  	      if (iptr->idx[0] == -1) {
  	        iptr->idx[0] = keyno-1;
-@@ -544,9 +541,9 @@ const char *fitshdr_errmsg[] = {
+@@ -544,17 +541,17 @@ const char *fitshdr_errmsg[] = {
  	    }
  	  }
  	
@@ -3830,9 +4397,10 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
 -	    /* Tidy up the previous string keyvalue. */
 +	    // Tidy up the previous string keyvalue.
  	    if ((kptr-1)->type == 8) (kptr-1)->type += 10;
- 	    cptr = (kptr-1)->keyvalue.s;
+-	    cptr = (kptr-1)->keyvalue.s;
++	    char *cptr = (kptr-1)->keyvalue.s;
  	    if (cptr[strlen(cptr)-1] == '&') cptr[strlen(cptr)-1] = '\0';
-@@ -554,7 +551,7 @@ const char *fitshdr_errmsg[] = {
+ 	
  	    kptr->type = (kptr-1)->type + 10;
  	  }
  	
@@ -3841,7 +4409,7 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
  	  if (end && (end++ > 1) && !blank) {
  	    kptr->status |= FITSHDR_TRAILER;
  	  }
-@@ -568,20 +565,20 @@ const char *fitshdr_errmsg[] = {
+@@ -568,30 +565,59 @@ const char *fitshdr_errmsg[] = {
  	}
  
  <<EOF>>	{
@@ -3853,22 +4421,65 @@ Index: astropy-4.2/cextern/wcslib/C/fitshdr.l
  %%
  
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
++/*----------------------------------------------------------------------------
++* External interface to the scanner.
++*---------------------------------------------------------------------------*/
  
- void nullfill(char cptr[], int len)
+-void nullfill(char cptr[], int len)
++int fitshdr(
++  const char header[],
++  int nkeyrec,
++  int nkeyids,
++  struct fitskeyid keyids[],
++  int *nreject,
++  struct fitskey **keys)
  
  {
-   int j, k;
+-  int j, k;
++  // Function prototypes.
++  int yylex_init_extra(YY_EXTRA_TYPE extra, yyscan_t *yyscanner);
++  int yylex_destroy(yyscan_t yyscanner);
  
 -  /* Null-fill the string. */
-+  // Null-fill the string.
++  struct fitshdr_extra extra;
++  yyscan_t yyscanner;
++  yylex_init_extra(&extra, &yyscanner);
++  int status = fitshdr_scanner(header, nkeyrec, nkeyids, keyids, nreject,
++                               keys, yyscanner);
++  yylex_destroy(yyscanner);
++
++  return status;
++}
++
++/*----------------------------------------------------------------------------
++* Pad a string with null characters.
++*---------------------------------------------------------------------------*/
++
++void nullfill(char cptr[], int len)
++
++{
++  // Propagate the terminating null to the end of the string.
++  int j;
    for (j = 0; j < len; j++) {
      if (cptr[j] == '\0') {
-       for (k = j+1; k < len; k++) {
-Index: astropy-4.2/cextern/wcslib/C/flexed/README
+-      for (k = j+1; k < len; k++) {
++      for (int k = j+1; k < len; k++) {
+         cptr[k] = '\0';
+       }
+       break;
+     }
+   }
+ 
+-  for (k = j-1; k >= 0; k--) {
++  // Remove trailing blanks.
++  for (int k = j-1; k >= 0; k--) {
+     if (cptr[k] != ' ') break;
+     cptr[k] = '\0';
+   }
+Index: astropy-4.2.1/cextern/wcslib/C/flexed/README
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/flexed/README
-+++ astropy-4.2/cextern/wcslib/C/flexed/README
+--- astropy-4.2.1.orig/cextern/wcslib/C/flexed/README
++++ astropy-4.2.1/cextern/wcslib/C/flexed/README
 @@ -1,5 +1,5 @@
  This directory contains C code generated by flex 2.6.4 under KDE Neon User
 -Edition 5.17 (Kubuntu 18.04) from the Flex description files (*.l) in the
@@ -3876,10 +4487,10 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/README
  parent directory.
  
  These pre-generated source files may be used during installation if
-Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
+Index: astropy-4.2.1/cextern/wcslib/C/flexed/fitshdr.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/flexed/fitshdr.c
-+++ astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/flexed/fitshdr.c
++++ astropy-4.2.1/cextern/wcslib/C/flexed/fitshdr.c
 @@ -10233,9 +10233,8 @@ static const yy_state_type yy_NUL_trans[
  #define YY_RESTORE_YY_MORE_OFFSET
  #line 1 "fitshdr.l"
@@ -3887,7 +4498,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -3901,7 +4512,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: fitshdr.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: fitshdr.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: fitshdr.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
  * fitshdr.l is a Flex description file containing a lexical scanner
@@ -3910,43 +4521,89 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  /* Exclusive start states. */
  
 -#line 78 "fitshdr.l"
-+#line 75 "fitshdr.l"
++#line 76 "fitshdr.l"
  #include <math.h>
  #include <limits.h>
  #include <setjmp.h>
-@@ -10289,7 +10286,7 @@ static int fitshdr_scanner(const char he
-                            struct fitskeyid keyids[], int *nreject, \
-                            struct fitskey **keys, yyscan_t yyscanner);
+@@ -10285,35 +10282,15 @@ static const yy_state_type yy_NUL_trans[
+ #include "fitshdr.h"
+ #include "wcsutil.h"
  
+-static int fitshdr_scanner(const char header[], int nkeyrec, int nkeyids, \
+-                           struct fitskeyid keyids[], int *nreject, \
+-                           struct fitskey **keys, yyscan_t yyscanner);
+-
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
- 
- int fitshdr(
-   const char header[],
-@@ -10313,7 +10310,7 @@ int fitshdr(
-   return status;
- }
- 
+-
+-int fitshdr(
+-  const char header[],
+-  int nkeyrec,
+-  int nkeyids,
+-  struct fitskeyid keyids[],
+-  int *nreject,
+-  struct fitskey **keys)
+-
+-{
+-  int status;
+-  yyscan_t yyscanner;
+-  int yylex_init(yyscan_t *yyscanner);
+-  int yylex_destroy(yyscan_t yyscanner);
+-
+-  yylex_init(&yyscanner);
+-  status = fitshdr_scanner(header, nkeyrec, nkeyids, keyids, nreject,
+-                           keys, yyscanner);
+-  yylex_destroy(yyscanner);
+-
+-  return status;
+-}
+-
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
++// User data associated with yyscanner.
++struct fitshdr_extra {
++  // Values passed to YY_INPUT.
++  const char *hdr;
++  int  nkeyrec;
++
++  // Used in preempting the call to exit() by yy_fatal_error().
++  jmp_buf abort_jmp_env;
++};
  
  #define YY_DECL int fitshdr_scanner(const char header[], int nkeyrec, \
    int nkeyids, struct fitskeyid keyids[], int *nreject, \
-@@ -10332,23 +10329,23 @@ int fitshdr(
+@@ -10321,34 +10298,33 @@ int fitshdr(
+ 
+ #define YY_INPUT(inbuff, count, bufsize) \
+ 	{ \
+-	  if (fitshdr_nkeyrec) { \
+-	    strncpy(inbuff, fitshdr_hdr, 80); \
++	  if (yyextra->nkeyrec) { \
++	    strncpy(inbuff, yyextra->hdr, 80); \
+ 	    inbuff[80] = '\n'; \
+-	    fitshdr_hdr += 80; \
+-	    fitshdr_nkeyrec--; \
++	    yyextra->hdr += 80; \
++	    yyextra->nkeyrec--; \
+ 	    count = 81; \
+ 	  } else { \
+ 	    count = YY_NULL; \
  	  } \
  	}
  
 -/* These global variables are required by YY_INPUT. */
-+// These global variables are required by YY_INPUT.
- const char *fitshdr_hdr;
- int  fitshdr_nkeyrec;
- 
+-const char *fitshdr_hdr;
+-int  fitshdr_nkeyrec;
+-
 -/* Used in preempting the call to exit() by yy_fatal_error(). */
-+// Used in preempting the call to exit() by yy_fatal_error().
- jmp_buf fitshdr_abort_jmp_env;
- #define exit(status) longjmp(fitshdr_abort_jmp_env, status)
+-jmp_buf fitshdr_abort_jmp_env;
+-#define exit(status) longjmp(fitshdr_abort_jmp_env, status)
++// Preempt the call to exit() by yy_fatal_error().
++#define exit(status) longjmp(yyextra->abort_jmp_env, status);
  
 -/* Map status return value to message. */
++// Internal helper functions.
++static YY_DECL;
++static void nullfill(char cptr[], int len);
++
 +// Map status return value to message.
  const char *fitshdr_errmsg[] = {
     "Success",
@@ -3956,126 +4613,188 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  
 -#line 10351 "fitshdr.c"
 -#line 10352 "fitshdr.c"
-+#line 10348 "fitshdr.c"
-+#line 10349 "fitshdr.c"
++#line 10327 "fitshdr.c"
++#line 10328 "fitshdr.c"
  
  #define INITIAL 0
  #define VALUE 1
-@@ -10599,9 +10596,9 @@ YY_DECL
+@@ -10366,9 +10342,7 @@ const char *fitshdr_errmsg[] = {
+ #include <unistd.h>
+ #endif
+ 
+-#ifndef YY_EXTRA_TYPE
+-#define YY_EXTRA_TYPE void *
+-#endif
++#define YY_EXTRA_TYPE struct fitshdr_extra *
+ 
+ /* Holds the entire state of the reentrant scanner. */
+ struct yyguts_t
+@@ -10599,52 +10573,67 @@ YY_DECL
  		}
  
  	{
 -#line 151 "fitshdr.l"
-+#line 148 "fitshdr.l"
++#line 128 "fitshdr.l"
  
 -#line 153 "fitshdr.l"
-+#line 150 "fitshdr.l"
- 	char *cptr, ctmp[72];
- 	int  blank, continuation, end, j, k, keyno;
- 	double dtmp;
-@@ -10619,13 +10616,13 @@ YY_DECL
- 	  return 1;
+-	char *cptr, ctmp[72];
+-	int  blank, continuation, end, j, k, keyno;
+-	double dtmp;
+-	struct fitskey *kptr;
+-	struct fitskeyid *iptr;
+-	void nullfill(char cptr[], int len);
+-	
+-	fitshdr_hdr = header;
+-	fitshdr_nkeyrec = nkeyrec;
+-	
+-	*nreject = 0;
+-	keyno = 0;
++#line 130 "fitshdr.l"
++	char ctmp[72];
+ 	
+ 	if (keys == 0x0) {
+-	  return 1;
++	  return FITSHDRERR_NULL_POINTER;
  	}
  	
 -	/* Allocate memory for the required number of fitskey structs. */
 -	/* Recall that calloc() initializes allocated memory to zero.  */
 +	// Allocate memory for the required number of fitskey structs.
 +	// Recall that calloc() initializes allocated memory to zero.
++	struct fitskey *kptr;
  	if (!(kptr = *keys = calloc(nkeyrec, sizeof(struct fitskey)))) {
- 	  return 2;
+-	  return 2;
++	  return FITSHDRERR_MEMORY;
  	}
  	
 -	/* Initialize keyids[]. */
+-	iptr = keyids;
+-	for (j = 0; j < nkeyids; j++, iptr++) {
++	// Initialize returned values.
++	*nreject = 0;
++	
 +	// Initialize keyids[].
- 	iptr = keyids;
- 	for (j = 0; j < nkeyids; j++, iptr++) {
++	struct fitskeyid *iptr = keyids;
++	for (int j = 0; j < nkeyids; j++, iptr++) {
  	  iptr->count  = 0;
-@@ -10637,14 +10634,14 @@ YY_DECL
- 	continuation = 0;
- 	end = 0;
+ 	  iptr->idx[0] = -1;
+ 	  iptr->idx[1] = -1;
+ 	}
++
++	int keyno = 0;
++	
++	int blank = 0;
++	int continuation = 0;
++	int end = 0;
  	
+-	blank = 0;
+-	continuation = 0;
+-	end = 0;
+-	
 -	/* Return here via longjmp() invoked by yy_fatal_error(). */
+-	if (setjmp(fitshdr_abort_jmp_env)) {
+-	  return 3;
++#ifdef WCSLIB_INT64
++#define asString(S) stringize(S)
++#define stringize(S) #S
++	
++	  const char *int64fmt;
++	  if (strcmp(asString(WCSLIB_INT64), "long long int") == 0) {
++	    int64fmt = "%lld";
++	  } else if (strcmp(asString(WCSLIB_INT64), "long int") == 0) {
++	    int64fmt = "%ld";
++	  } else if (strcmp(asString(WCSLIB_INT64), "int") == 0) {
++	    int64fmt = "%d";
++	  } else {
++	    return FITSHDRERR_DATA_TYPE;
++	  }
++#endif
++	
++	// User data associated with yyscanner.
++	yyextra->hdr = header;
++	yyextra->nkeyrec = nkeyrec;
++	
 +	// Return here via longjmp() invoked by yy_fatal_error().
- 	if (setjmp(fitshdr_abort_jmp_env)) {
- 	  return 3;
++	if (setjmp(yyextra->abort_jmp_env)) {
++	  return FITSHDRERR_FLEX_PARSER;
  	}
  	
  	BEGIN(INITIAL);
  
 -#line 10648 "fitshdr.c"
-+#line 10645 "fitshdr.c"
++#line 10637 "fitshdr.c"
  
  	while ( /*CONSTCOND*/1 )		/* loops until end-of-file is reached */
  		{
-@@ -10698,9 +10695,9 @@ do_action:	/* This label is used only to
+@@ -10698,9 +10687,9 @@ do_action:	/* This label is used only to
  
  case 1:
  YY_RULE_SETUP
 -#line 195 "fitshdr.l"
-+#line 192 "fitshdr.l"
++#line 187 "fitshdr.l"
  {
 -	  /* A completely blank keyrecord. */
 +	  // A completely blank keyrecord.
  	  strncpy(kptr->keyword, yytext, 8);
  	  yyless(0);
  	  blank = 1;
-@@ -10709,7 +10706,7 @@ YY_RULE_SETUP
+@@ -10709,7 +10698,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 2:
  YY_RULE_SETUP
 -#line 203 "fitshdr.l"
-+#line 200 "fitshdr.l"
++#line 195 "fitshdr.l"
  {
  	  strncpy(kptr->keyword, yytext, 8);
  	  BEGIN(COMMENT);
-@@ -10717,7 +10714,7 @@ YY_RULE_SETUP
+@@ -10717,7 +10706,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 3:
  YY_RULE_SETUP
 -#line 208 "fitshdr.l"
-+#line 205 "fitshdr.l"
++#line 200 "fitshdr.l"
  {
  	  strncpy(kptr->keyword, yytext, 8);
  	  end = 1;
-@@ -10726,9 +10723,9 @@ YY_RULE_SETUP
+@@ -10726,9 +10715,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 4:
  YY_RULE_SETUP
 -#line 214 "fitshdr.l"
-+#line 211 "fitshdr.l"
++#line 206 "fitshdr.l"
  {
 -	  /* Illegal END keyrecord. */
 +	  // Illegal END keyrecord.
  	  strncpy(kptr->keyword, yytext, 8);
  	  kptr->status |= FITSHDR_KEYREC;
  	  BEGIN(VALUE);
-@@ -10736,9 +10733,9 @@ YY_RULE_SETUP
+@@ -10736,9 +10725,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 5:
  YY_RULE_SETUP
 -#line 221 "fitshdr.l"
-+#line 218 "fitshdr.l"
++#line 213 "fitshdr.l"
  {
 -	  /* Illegal END keyrecord. */
 +	  // Illegal END keyrecord.
  	  strncpy(kptr->keyword, yytext, 8);
  	  kptr->status |= FITSHDR_KEYREC;
  	  BEGIN(COMMENT);
-@@ -10746,7 +10743,7 @@ YY_RULE_SETUP
+@@ -10746,7 +10735,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 6:
  YY_RULE_SETUP
 -#line 228 "fitshdr.l"
-+#line 225 "fitshdr.l"
++#line 220 "fitshdr.l"
  {
  	  strncpy(kptr->keyword, yytext, 8);
  	  BEGIN(VALUE);
-@@ -10755,20 +10752,20 @@ YY_RULE_SETUP
+@@ -10755,20 +10744,21 @@ YY_RULE_SETUP
  case 7:
  /* rule 7 can match eol */
  YY_RULE_SETUP
 -#line 233 "fitshdr.l"
-+#line 230 "fitshdr.l"
++#line 225 "fitshdr.l"
  {
 -	  /* Continued string keyvalue. */
 +	  // Continued string keyvalue.
@@ -4084,6 +4803,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  	  if (keyno > 0 && (kptr-1)->type%10 == 8) {
 -	    /* Put back the string keyvalue. */
 +	    // Put back the string keyvalue.
++	    int k;
  	    for (k = 10; yytext[k] != '\''; k++);
  	    yyless(k);
  	    continuation = 1;
@@ -4095,12 +4815,12 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  	    yyless(8);
  	    BEGIN(COMMENT);
  	  }
-@@ -10776,18 +10773,18 @@ YY_RULE_SETUP
+@@ -10776,18 +10766,18 @@ YY_RULE_SETUP
  	YY_BREAK
  case 8:
  YY_RULE_SETUP
 -#line 251 "fitshdr.l"
-+#line 248 "fitshdr.l"
++#line 244 "fitshdr.l"
  {
 -	  /* Keyword without value. */
 +	  // Keyword without value.
@@ -4111,31 +4831,31 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  case 9:
  YY_RULE_SETUP
 -#line 257 "fitshdr.l"
-+#line 254 "fitshdr.l"
++#line 250 "fitshdr.l"
  {
 -	  /* Illegal keyword, carry on regardless. */
 +	  // Illegal keyword, carry on regardless.
  	  strncpy(kptr->keyword, yytext, 8);
  	  kptr->status |= FITSHDR_KEYWORD;
  	  BEGIN(VALUE);
-@@ -10795,9 +10792,9 @@ YY_RULE_SETUP
+@@ -10795,9 +10785,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 10:
  YY_RULE_SETUP
 -#line 264 "fitshdr.l"
-+#line 261 "fitshdr.l"
++#line 257 "fitshdr.l"
  {
 -	  /* Illegal keyword, carry on regardless. */
 +	  // Illegal keyword, carry on regardless.
  	  strncpy(kptr->keyword, yytext, 8);
  	  kptr->status |= FITSHDR_KEYWORD;
  	  BEGIN(COMMENT);
-@@ -10808,17 +10805,17 @@ case 11:
+@@ -10808,17 +10798,17 @@ case 11:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 271 "fitshdr.l"
-+#line 268 "fitshdr.l"
++#line 264 "fitshdr.l"
  {
 -	  /* Null keyvalue. */
 +	  // Null keyvalue.
@@ -4145,34 +4865,35 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  case 12:
  YY_RULE_SETUP
 -#line 276 "fitshdr.l"
-+#line 273 "fitshdr.l"
++#line 269 "fitshdr.l"
  {
 -	  /* Logical keyvalue. */
 +	  // Logical keyvalue.
  	  kptr->type = 1;
  	  kptr->keyvalue.i = (*yytext == 'T');
  	  BEGIN(INLINE);
-@@ -10826,9 +10823,9 @@ YY_RULE_SETUP
+@@ -10826,9 +10816,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 13:
  YY_RULE_SETUP
 -#line 283 "fitshdr.l"
-+#line 280 "fitshdr.l"
++#line 276 "fitshdr.l"
  {
 -	  /* 32-bit signed integer keyvalue. */
 +	  // 32-bit signed integer keyvalue.
  	  kptr->type = 2;
  	  if (sscanf(yytext, "%d", &(kptr->keyvalue.i)) < 1) {
  	    kptr->status |= FITSHDR_KEYVALUE;
-@@ -10840,15 +10837,15 @@ YY_RULE_SETUP
+@@ -10840,15 +10830,16 @@ YY_RULE_SETUP
  	YY_BREAK
  case 14:
  YY_RULE_SETUP
 -#line 294 "fitshdr.l"
-+#line 291 "fitshdr.l"
++#line 287 "fitshdr.l"
  {
 -	  /* 64-bit signed integer keyvalue (up to 18 digits). */
 +	  // 64-bit signed integer keyvalue (up to 18 digits).
++	  double dtmp;
  	  if (wcsutil_str2double(yytext, &dtmp)) {
  	    kptr->status |= FITSHDR_KEYVALUE;
  	    BEGIN(ERROR);
@@ -4183,7 +4904,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  	    kptr->type = 2;
  	    if (sscanf(yytext, "%d", &(kptr->keyvalue.i)) < 1) {
  	      kptr->status |= FITSHDR_KEYVALUE;
-@@ -10856,16 +10853,16 @@ YY_RULE_SETUP
+@@ -10856,16 +10847,16 @@ YY_RULE_SETUP
  	    }
  	
  	  } else {
@@ -4192,8 +4913,9 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  	    kptr->type = 3;
  #ifdef WCSLIB_INT64
 -	      /* Native 64-bit integer is available. */
+-	      if (sscanf(yytext, "%lld", &(kptr->keyvalue.k)) < 1) {
 +	      // Native 64-bit integer is available.
- 	      if (sscanf(yytext, "%lld", &(kptr->keyvalue.k)) < 1) {
++	      if (sscanf(yytext, int64fmt, &(kptr->keyvalue.k)) < 1) {
  	        kptr->status |= FITSHDR_KEYVALUE;
  	        BEGIN(ERROR);
  	      }
@@ -4203,25 +4925,26 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  	      kptr->keyvalue.k[2] = 0;
  	
  	      sprintf(ctmp, "%%%dd%%9d", yyleng-9);
-@@ -10884,14 +10881,14 @@ YY_RULE_SETUP
+@@ -10884,14 +10875,14 @@ YY_RULE_SETUP
  	YY_BREAK
  case 15:
  YY_RULE_SETUP
 -#line 335 "fitshdr.l"
-+#line 332 "fitshdr.l"
++#line 329 "fitshdr.l"
  {
 -	  /* Very long integer keyvalue (and 19-digit int64). */
 +	  // Very long integer keyvalue (and 19-digit int64).
  	  kptr->type = 4;
  	  strcpy(ctmp, yytext);
- 	  k = yyleng;
+-	  k = yyleng;
++	  int j, k = yyleng;
  	  for (j = 0; j < 8; j++) {
 -	    /* Read it backwards. */
 +	    // Read it backwards.
  	    k -= 9;
  	    if (k < 0) k = 0;
  	    if (sscanf(ctmp+k, "%d", kptr->keyvalue.l+j) < 1) {
-@@ -10906,7 +10903,7 @@ YY_RULE_SETUP
+@@ -10906,7 +10897,7 @@ YY_RULE_SETUP
  	    ctmp[k] = '\0';
  	  }
  	
@@ -4230,70 +4953,82 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  	  if (j == 2 && abs(kptr->keyvalue.l[2]) <=  9 &&
  	                abs(kptr->keyvalue.l[1]) <=  223372036 &&
  	                    kptr->keyvalue.l[0]  <=  854775807 &&
-@@ -10914,7 +10911,7 @@ YY_RULE_SETUP
+@@ -10914,9 +10905,9 @@ YY_RULE_SETUP
  	    kptr->type = 3;
  	
  #ifdef WCSLIB_INT64
 -	      /* Native 64-bit integer is available. */
 +	      // Native 64-bit integer is available.
  	      kptr->keyvalue.l[2] = 0;
- 	      if (sscanf(yytext, "%lld", &(kptr->keyvalue.k)) < 1) {
+-	      if (sscanf(yytext, "%lld", &(kptr->keyvalue.k)) < 1) {
++	      if (sscanf(yytext, int64fmt, &(kptr->keyvalue.k)) < 1) {
  	        kptr->status |= FITSHDR_KEYVALUE;
-@@ -10928,9 +10925,9 @@ YY_RULE_SETUP
+ 	        BEGIN(ERROR);
+ 	      }
+@@ -10928,9 +10919,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 16:
  YY_RULE_SETUP
 -#line 376 "fitshdr.l"
-+#line 373 "fitshdr.l"
++#line 370 "fitshdr.l"
  {
 -	  /* Float keyvalue. */
 +	  // Float keyvalue.
  	  kptr->type = 5;
  	  if (wcsutil_str2double(yytext, &(kptr->keyvalue.f))) {
  	    kptr->status |= FITSHDR_KEYVALUE;
-@@ -10942,9 +10939,9 @@ YY_RULE_SETUP
+@@ -10942,9 +10933,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 17:
  YY_RULE_SETUP
 -#line 387 "fitshdr.l"
-+#line 384 "fitshdr.l"
++#line 381 "fitshdr.l"
  {
 -	  /* Integer complex keyvalue. */
 +	  // Integer complex keyvalue.
  	  kptr->type = 6;
  	  if (sscanf(yytext, "(%lf,%lf)", kptr->keyvalue.c,
  	      kptr->keyvalue.c+1) < 2) {
-@@ -10957,9 +10954,9 @@ YY_RULE_SETUP
+@@ -10957,11 +10948,13 @@ YY_RULE_SETUP
  	YY_BREAK
  case 18:
  YY_RULE_SETUP
 -#line 399 "fitshdr.l"
-+#line 396 "fitshdr.l"
++#line 393 "fitshdr.l"
  {
 -	  /* Floating point complex keyvalue. */
 +	  // Floating point complex keyvalue.
  	  kptr->type = 7;
  	
++	  char *cptr;
++	  int k;
  	  for (cptr = ctmp, k = 1; yytext[k] != ','; cptr++, k++) {
-@@ -10988,14 +10985,14 @@ YY_RULE_SETUP
+ 	    *cptr = yytext[k];
+ 	  }
+@@ -10988,16 +10981,16 @@ YY_RULE_SETUP
  case 19:
  /* rule 19 can match eol */
  YY_RULE_SETUP
 -#line 426 "fitshdr.l"
-+#line 423 "fitshdr.l"
++#line 422 "fitshdr.l"
  {
 -	  /* String keyvalue. */
 +	  // String keyvalue.
  	  kptr->type = 8;
- 	  cptr = kptr->keyvalue.s;
+-	  cptr = kptr->keyvalue.s;
++	  char *cptr = kptr->keyvalue.s;
  	  strcpy(cptr, yytext+1);
  	
 -	  /* Squeeze out repeated quotes. */
+-	  k = 0;
+-	  for (j = 0; j < 72; j++) {
 +	  // Squeeze out repeated quotes.
- 	  k = 0;
- 	  for (j = 0; j < 72; j++) {
++	  int k = 0;
++	  for (int j = 0; j < 72; j++) {
  	    if (k < j) {
-@@ -11013,7 +11010,7 @@ YY_RULE_SETUP
+ 	      cptr[k] = cptr[j];
+ 	    }
+@@ -11013,7 +11006,7 @@ YY_RULE_SETUP
  	  }
  	
  	  if (*cptr) {
@@ -4302,30 +5037,30 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  	    nullfill(cptr+1, 71);
  	  } else {
  	    nullfill(cptr, 72);
-@@ -11024,7 +11021,7 @@ YY_RULE_SETUP
+@@ -11024,7 +11017,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 20:
  YY_RULE_SETUP
 -#line 459 "fitshdr.l"
-+#line 456 "fitshdr.l"
++#line 455 "fitshdr.l"
  {
  	  kptr->status |= FITSHDR_KEYVALUE;
  	  BEGIN(ERROR);
-@@ -11035,7 +11032,7 @@ case 21:
+@@ -11035,7 +11028,7 @@ case 21:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 464 "fitshdr.l"
-+#line 461 "fitshdr.l"
++#line 460 "fitshdr.l"
  {
  	  BEGIN(FLUSH);
  	}
-@@ -11045,21 +11042,21 @@ case 22:
+@@ -11045,21 +11038,21 @@ case 22:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 468 "fitshdr.l"
-+#line 465 "fitshdr.l"
++#line 464 "fitshdr.l"
  {
  	  BEGIN(FLUSH);
  	}
@@ -4333,7 +5068,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  case 23:
  YY_RULE_SETUP
 -#line 472 "fitshdr.l"
-+#line 469 "fitshdr.l"
++#line 468 "fitshdr.l"
  {
  	  BEGIN(UNITS);
  	}
@@ -4341,64 +5076,69 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  case 24:
  YY_RULE_SETUP
 -#line 476 "fitshdr.l"
-+#line 473 "fitshdr.l"
++#line 472 "fitshdr.l"
  {
  	  kptr->status |= FITSHDR_COMMENT;
  	  BEGIN(ERROR);
-@@ -11067,9 +11064,9 @@ YY_RULE_SETUP
+@@ -11067,9 +11060,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 25:
  YY_RULE_SETUP
 -#line 481 "fitshdr.l"
-+#line 478 "fitshdr.l"
++#line 477 "fitshdr.l"
  {
 -	  /* Keyvalue parsing must now also be suspect. */
 +	  // Keyvalue parsing must now also be suspect.
  	  kptr->status |= FITSHDR_COMMENT;
  	  kptr->type = 0;
  	  BEGIN(ERROR);
-@@ -11077,7 +11074,7 @@ YY_RULE_SETUP
+@@ -11077,7 +11070,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 26:
  YY_RULE_SETUP
 -#line 488 "fitshdr.l"
-+#line 485 "fitshdr.l"
++#line 484 "fitshdr.l"
  {
  	  kptr->ulen = yyleng;
  	  yymore();
-@@ -11086,7 +11083,7 @@ YY_RULE_SETUP
+@@ -11086,7 +11079,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 27:
  YY_RULE_SETUP
 -#line 494 "fitshdr.l"
-+#line 491 "fitshdr.l"
++#line 490 "fitshdr.l"
  {
  	  yymore();
  	  BEGIN(COMMENT);
-@@ -11094,7 +11091,7 @@ YY_RULE_SETUP
+@@ -11094,7 +11087,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 28:
  YY_RULE_SETUP
 -#line 499 "fitshdr.l"
-+#line 496 "fitshdr.l"
++#line 495 "fitshdr.l"
  {
  	  strcpy(kptr->comment, yytext);
  	  nullfill(kptr->comment, 84);
-@@ -11103,7 +11100,7 @@ YY_RULE_SETUP
+@@ -11103,11 +11096,11 @@ YY_RULE_SETUP
  	YY_BREAK
  case 29:
  YY_RULE_SETUP
 -#line 505 "fitshdr.l"
-+#line 502 "fitshdr.l"
++#line 501 "fitshdr.l"
  {
  	  if (!continuation) kptr->type = -abs(kptr->type);
  	
-@@ -11117,16 +11114,16 @@ YY_RULE_SETUP
+-	  sprintf(kptr->comment, "%.80s", fitshdr_hdr-80);
++	  sprintf(kptr->comment, "%.80s", yyextra->hdr-80);
+ 	  kptr->comment[80] = '\0';
+ 	  nullfill(kptr->comment+80, 4);
+ 	
+@@ -11117,20 +11110,21 @@ YY_RULE_SETUP
  case 30:
  /* rule 30 can match eol */
  YY_RULE_SETUP
 -#line 515 "fitshdr.l"
-+#line 512 "fitshdr.l"
++#line 511 "fitshdr.l"
  {
 -	  /* Discard the rest of the input line. */
 +	  // Discard the rest of the input line.
@@ -4413,8 +5153,15 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
 +	  // Do indexing.
  	  iptr = keyids;
  	  kptr->keyid = -1;
- 	  for (j = 0; j < nkeyids; j++, iptr++) {
-@@ -11138,7 +11135,7 @@ YY_RULE_SETUP
+-	  for (j = 0; j < nkeyids; j++, iptr++) {
+-	    cptr = iptr->name;
++	  for (int j = 0; j < nkeyids; j++, iptr++) {
++	    int k;
++	    char *cptr = iptr->name;
+ 	    cptr[8] = '\0';
+ 	    nullfill(cptr, 12);
+ 	    for (k = 0; k < 8; k++, cptr++) {
+@@ -11138,7 +11132,7 @@ YY_RULE_SETUP
  	    }
  	
  	    if (k == 8) {
@@ -4423,7 +5170,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  	      iptr->count++;
  	      if (iptr->idx[0] == -1) {
  	        iptr->idx[0] = keyno-1;
-@@ -11151,9 +11148,9 @@ YY_RULE_SETUP
+@@ -11151,17 +11145,17 @@ YY_RULE_SETUP
  	    }
  	  }
  	
@@ -4433,9 +5180,10 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
 -	    /* Tidy up the previous string keyvalue. */
 +	    // Tidy up the previous string keyvalue.
  	    if ((kptr-1)->type == 8) (kptr-1)->type += 10;
- 	    cptr = (kptr-1)->keyvalue.s;
+-	    cptr = (kptr-1)->keyvalue.s;
++	    char *cptr = (kptr-1)->keyvalue.s;
  	    if (cptr[strlen(cptr)-1] == '&') cptr[strlen(cptr)-1] = '\0';
-@@ -11161,7 +11158,7 @@ YY_RULE_SETUP
+ 	
  	    kptr->type = (kptr-1)->type + 10;
  	  }
  	
@@ -4444,7 +5192,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  	  if (end && (end++ > 1) && !blank) {
  	    kptr->status |= FITSHDR_TRAILER;
  	  }
-@@ -11181,18 +11178,18 @@ case YY_STATE_EOF(UNITS):
+@@ -11181,18 +11175,18 @@ case YY_STATE_EOF(UNITS):
  case YY_STATE_EOF(COMMENT):
  case YY_STATE_EOF(ERROR):
  case YY_STATE_EOF(FLUSH):
@@ -4463,11 +5211,11 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  ECHO;
  	YY_BREAK
 -#line 11196 "fitshdr.c"
-+#line 11193 "fitshdr.c"
++#line 11190 "fitshdr.c"
  
  	case YY_END_OF_BUFFER:
  		{
-@@ -12319,17 +12316,17 @@ void yyfree (void * ptr , yyscan_t yysca
+@@ -12319,27 +12313,56 @@ void yyfree (void * ptr , yyscan_t yysca
  
  #define YYTABLES_NAME "yytables"
  
@@ -4476,22 +5224,65 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/fitshdr.c
  
  
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
++/*----------------------------------------------------------------------------
++* External interface to the scanner.
++*---------------------------------------------------------------------------*/
  
- void nullfill(char cptr[], int len)
+-void nullfill(char cptr[], int len)
++int fitshdr(
++  const char header[],
++  int nkeyrec,
++  int nkeyids,
++  struct fitskeyid keyids[],
++  int *nreject,
++  struct fitskey **keys)
  
  {
-   int j, k;
+-  int j, k;
++  // Function prototypes.
++  int yylex_init_extra(YY_EXTRA_TYPE extra, yyscan_t *yyscanner);
++  int yylex_destroy(yyscan_t yyscanner);
  
 -  /* Null-fill the string. */
-+  // Null-fill the string.
++  struct fitshdr_extra extra;
++  yyscan_t yyscanner;
++  yylex_init_extra(&extra, &yyscanner);
++  int status = fitshdr_scanner(header, nkeyrec, nkeyids, keyids, nreject,
++                               keys, yyscanner);
++  yylex_destroy(yyscanner);
++
++  return status;
++}
++
++/*----------------------------------------------------------------------------
++* Pad a string with null characters.
++*---------------------------------------------------------------------------*/
++
++void nullfill(char cptr[], int len)
++
++{
++  // Propagate the terminating null to the end of the string.
++  int j;
    for (j = 0; j < len; j++) {
      if (cptr[j] == '\0') {
-       for (k = j+1; k < len; k++) {
-Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
+-      for (k = j+1; k < len; k++) {
++      for (int k = j+1; k < len; k++) {
+         cptr[k] = '\0';
+       }
+       break;
+     }
+   }
+ 
+-  for (k = j-1; k >= 0; k--) {
++  // Remove trailing blanks.
++  for (int k = j-1; k >= 0; k--) {
+     if (cptr[k] != ' ') break;
+     cptr[k] = '\0';
+   }
+Index: astropy-4.2.1/cextern/wcslib/C/flexed/wcsbth.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/flexed/wcsbth.c
-+++ astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/flexed/wcsbth.c
++++ astropy-4.2.1/cextern/wcslib/C/flexed/wcsbth.c
 @@ -25388,9 +25388,8 @@ static const yy_state_type yy_NUL_trans[
  #define YY_RESTORE_YY_MORE_OFFSET
  #line 1 "wcsbth.l"
@@ -4499,7 +5290,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -4513,7 +5304,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcsbth.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcsbth.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcsbth.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
  * wcsbth.l is a Flex description file containing the definition of a lexical
@@ -4522,11 +5313,11 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  
  
 -#line 115 "wcsbth.l"
-+#line 112 "wcsbth.l"
++#line 113 "wcsbth.l"
  #include <math.h>
  #include <setjmp.h>
  #include <stddef.h>
-@@ -25487,30 +25484,30 @@ static const yy_state_type yy_NUL_trans[
+@@ -25487,57 +25484,34 @@ static const yy_state_type yy_NUL_trans[
  #include "wcsprintf.h"
  #include "wcsutil.h"
  
@@ -4549,6 +5340,10 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
 -#define BINTAB  0xC	/* BIMGARR | PIXLIST, i.e. binary table     */
 -			/* image array (without axis number) or     */
 -			/* pixel list, e.g. LONPna or OBSGXn.       */
+-
+-static int wcsbth_scanner(char *header, int nkeyrec, int relax, int ctrl,
+-                          int keysel, int *colsel, int *nreject, int *nwcs,
+-                          struct wcsprm **wcs, yyscan_t yyscanner);
 +			// Bit masks used for keyword types:
 +#define IMGAUX  0x1	// Auxiliary image header, e.g. LONPOLEa or
 +			// DATE-OBS.
@@ -4561,58 +5356,99 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
 +#define BINTAB  0xC	// BIMGARR | PIXLIST, i.e. binary table
 +			// image array (without axis number) or
 +			// pixel list, e.g. LONPna or OBSGXn.
- 
- static int wcsbth_scanner(char *header, int nkeyrec, int relax, int ctrl,
-                           int keysel, int *colsel, int *nreject, int *nwcs,
-                           struct wcsprm **wcs, yyscan_t yyscanner);
++
++// User data associated with yyscanner.
++struct wcsbth_extra {
++  // Values passed to YY_INPUT.
++  char *hdr;
++  int  nkeyrec;
  
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
- 
- int wcsbth(
-   char *header,
-@@ -25537,7 +25534,7 @@ int wcsbth(
-   return status;
- }
- 
+-
+-int wcsbth(
+-  char *header,
+-  int nkeyrec,
+-  int relax,
+-  int ctrl,
+-  int keysel,
+-  int *colsel,
+-  int *nreject,
+-  int *nwcs,
+-  struct wcsprm **wcs)
+-
+-{
+-  int status;
+-  yyscan_t yyscanner;
+-  int yylex_init(yyscan_t *yyscanner);
+-  int yylex_destroy(yyscan_t yyscanner);
+-
+-  yylex_init(&yyscanner);
+-  status = wcsbth_scanner(header, nkeyrec, relax, ctrl, keysel, colsel,
+-                          nreject, nwcs, wcs, yyscanner);
+-  yylex_destroy(yyscanner);
+-
+-  return status;
+-}
+-
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
++  // Used in preempting the call to exit() by yy_fatal_error().
++  jmp_buf abort_jmp_env;
++};
  
  #define YY_DECL int wcsbth_scanner(char *header, int nkeyrec, int relax, \
   int ctrl, int keysel, int *colsel, int *nreject, int *nwcs, \
-@@ -25556,18 +25553,18 @@ int wcsbth(
+@@ -25545,29 +25519,28 @@ int wcsbth(
+ 
+ #define YY_INPUT(inbuff, count, bufsize) \
+ 	{ \
+-	  if (wcsbth_nkeyrec) { \
+-	    strncpy(inbuff, wcsbth_hdr, 80); \
++	  if (yyextra->nkeyrec) { \
++	    strncpy(inbuff, yyextra->hdr, 80); \
+ 	    inbuff[80] = '\n'; \
+-	    wcsbth_hdr += 80; \
+-	    wcsbth_nkeyrec--; \
++	    yyextra->hdr += 80; \
++	    yyextra->nkeyrec--; \
+ 	    count = 81; \
+ 	  } else { \
+ 	    count = YY_NULL; \
  	  } \
  	}
  
 -/* A convenience macro to get around incompatibilities between unput() and
 -   yyless(): put yytext followed by a blank back onto the input stream. */
++// Preempt the call to exit() by yy_fatal_error().
++#define exit(status) longjmp(yyextra->abort_jmp_env, status);
++
 +// A convenience macro to get around incompatibilities between unput() and
 +// yyless(): put yytext followed by a blank back onto the input stream.
  #define WCSBTH_PUTBACK \
    sprintf(strtmp, "%s ", yytext); \
-   iz = strlen(strtmp); \
+-  iz = strlen(strtmp); \
++  size_t iz = strlen(strtmp); \
    while (iz) unput(strtmp[--iz]);
  
 -/* These global variables are required by YY_INPUT. */
-+// These global variables are required by YY_INPUT.
- static char *wcsbth_hdr;
- static int  wcsbth_nkeyrec;
- 
+-static char *wcsbth_hdr;
+-static int  wcsbth_nkeyrec;
+-
 -/* Struct used internally for header bookkeeping. */
 +// Struct used internally for header bookkeeping.
  struct wcsbth_alts {
    int ncol, ialt, icol, imgherit;
    short int (*arridx)[27];
-@@ -25582,7 +25579,7 @@ struct wcsbth_alts {
+@@ -25582,7 +25555,8 @@ struct wcsbth_alts {
    unsigned char pad2[2];
  };
  
 -/* Internal helper functions. */
 +// Internal helper functions.
++static YY_DECL;
  static int wcsbth_colax(struct wcsprm *wcs, struct wcsbth_alts *alts, int k,
          char a);
  static int wcsbth_final(struct wcsbth_alts *alts, int *nwcs,
-@@ -25594,22 +25591,22 @@ static int wcsbth_init1(struct wcsbth_al
+@@ -25594,22 +25568,18 @@ static int wcsbth_init1(struct wcsbth_al
  static int wcsbth_pass1(int keytype, int i, int j, int n, int k, char a,
          char ptype, struct wcsbth_alts *alts);
  
@@ -4629,148 +5465,230 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  static int wcsbth_timepixr(double timepixr);
  
 -/* Used in preempting the call to exit() by yy_fatal_error(). */
-+// Used in preempting the call to exit() by yy_fatal_error().
- jmp_buf wcsbth_abort_jmp_env;
- #define exit(status) longjmp(wcsbth_abort_jmp_env, status)
- 
+-jmp_buf wcsbth_abort_jmp_env;
+-#define exit(status) longjmp(wcsbth_abort_jmp_env, status)
+-
 -#line 25612 "wcsbth.c"
 -#line 25613 "wcsbth.c"
-+#line 25609 "wcsbth.c"
-+#line 25610 "wcsbth.c"
++#line 25582 "wcsbth.c"
++#line 25583 "wcsbth.c"
  
  #define INITIAL 0
  #define CCCCCia 1
-@@ -25889,10 +25886,10 @@ YY_DECL
+@@ -25654,9 +25624,7 @@ jmp_buf wcsbth_abort_jmp_env;
+ #include <unistd.h>
+ #endif
+ 
+-#ifndef YY_EXTRA_TYPE
+-#define YY_EXTRA_TYPE void *
+-#endif
++#define YY_EXTRA_TYPE struct wcsbth_extra *
+ 
+ /* Holds the entire state of the reentrant scanner. */
+ struct yyguts_t
+@@ -25889,102 +25857,89 @@ YY_DECL
  		}
  
  	{
 -#line 251 "wcsbth.l"
-+#line 248 "wcsbth.l"
++#line 222 "wcsbth.l"
  
 -#line 253 "wcsbth.l"
 -	/* Keyword indices, as used in the WCS papers, e.g. iVn_ma, TPn_ka. */
-+#line 250 "wcsbth.l"
-+	// Keyword indices, as used in the WCS papers, e.g. iVn_ma, TPn_ka.
- 	char a;
- 	int  i, j, k, m, n;
- 	
-@@ -25911,37 +25908,37 @@ YY_DECL
- 	int (*chekval)(double);
- 	int (*special)(double *, const double *);
+-	char a;
+-	int  i, j, k, m, n;
+-	
+-	char *cptr, *errmsg, errtxt[80], exclude[1000], gotone, *hptr, *keep,
+-	     *keyname, *keyrec, ptype, strtmp[80];
+-	int  altlin, auxprm, ialt, icol, incl, imherit, inttmp, ipass, ipx,
+-	     itmp, ix, jx, keytype, naux, nother, nsel, npass, nvalid, status,
+-	     valtype;
+-	ptrdiff_t voff;
+-	size_t iz;
++#line 224 "wcsbth.l"
++	char *errmsg, errtxt[80], *keyname, strtmp[80];
++	int  auxprm, inttmp;
+ 	double dbltmp, dbl2tmp[2];
+-	void   *vptr, *wptr;
+-	struct wcsbth_alts alts;
+-	struct auxprm *auxp, auxtem;
+-	struct wcsprm *wcsp, wcstem;
+-	int (*chekval)(double);
+-	int (*special)(double *, const double *);
++	struct auxprm auxtem;
++	struct wcsprm wcstem;
  	
 -	/* The data structures produced. */
-+	// The data structures produced.
++	// Initialize returned values.
++	*nreject = 0;
  	*nwcs = 0;
  	*wcs  = 0x0;
  	
 -	/* Parameters used to implement YY_INPUT. */
-+	// Parameters used to implement YY_INPUT.
- 	wcsbth_hdr = header;
- 	wcsbth_nkeyrec = nkeyrec;
- 	
+-	wcsbth_hdr = header;
+-	wcsbth_nkeyrec = nkeyrec;
+-	
 -	/* Our handle on the input stream. */
-+	// Our handle on the input stream.
- 	keyrec = header;
- 	hptr = header;
- 	keep = 0x0;
- 	
+-	keyrec = header;
+-	hptr = header;
+-	keep = 0x0;
+-	
 -	/* For keeping tallies of keywords found. */
+-	*nreject = 0;
+-	nvalid = 0;
+-	nother = 0;
++	// Our handle on the input stream.
++	char *keyrec = header;
++	char *hptr = header;
++	char *keep = 0x0;
++	
 +	// For keeping tallies of keywords found.
- 	*nreject = 0;
- 	nvalid = 0;
- 	nother = 0;
++	int nvalid = 0;
++	int nother = 0;
  	
 -	/* Used to flag image header keywords that are always inherited. */
+-	imherit = 1;
 +	// Used to flag image header keywords that are always inherited.
- 	imherit = 1;
++	int imherit = 1;
  	
 -	/* If strict, then also reject. */
 +	// If strict, then also reject.
  	if (relax & WCSHDR_strict) relax |= WCSHDR_reject;
  	
 -	/* Keyword parameters. */
-+	// Keyword parameters.
- 	i = j = 0;
- 	n = k = 0;
- 	m = 0;
- 	a = ' ';
+-	i = j = 0;
+-	n = k = 0;
+-	m = 0;
+-	a = ' ';
++	// Keyword indices, as used in the WCS papers, e.g. iVn_ma, TPn_ka.
++	int i = 0;
++	int j = 0;
++	int k = 0;
++	int n = 0;
++	int m = 0;
++	char a = ' ';
  	
 -	/* Header bookkeeping. */
 +	// Header bookkeeping.
++	struct wcsbth_alts alts;
  	alts.ncol = 0;
  	alts.arridx  = 0x0;
  	alts.pixlist = 0x0;
-@@ -25954,12 +25951,12 @@ YY_DECL
+ 	alts.npv = 0x0;
+ 	alts.nps = 0x0;
+ 	
+-	for (ialt = 0; ialt < 27; ialt++) {
++	for (int ialt = 0; ialt < 27; ialt++) {
+ 	  alts.pixidx[ialt] = 0;
+ 	  alts.pixnpv[ialt] = 0;
  	  alts.pixnps[ialt] = 0;
  	}
  	
 -	/* For decoding the keyvalue. */
-+	// For decoding the keyvalue.
- 	keytype =  0;
- 	valtype = -1;
- 	vptr    = 0x0;
- 	
+-	keytype =  0;
+-	valtype = -1;
+-	vptr    = 0x0;
+-	
 -	/* For keywords that require special handling. */
-+	// For keywords that require special handling.
- 	altlin  = 0;
- 	ptype   = ' ';
- 	chekval = 0x0;
-@@ -25967,7 +25964,7 @@ YY_DECL
- 	auxprm  = 0;
- 	naux    = 0;
- 	
+-	altlin  = 0;
+-	ptype   = ' ';
+-	chekval = 0x0;
+-	special = 0x0;
+-	auxprm  = 0;
+-	naux    = 0;
+-	
 -	/* Selection by column number. */
+-	nsel = colsel ? colsel[0] : 0;
+-	incl = (nsel > 0);
+-	for (icol = 0; icol < 1000; icol++) {
++	// For decoding the keyvalue.
++	int keytype =  0;
++	int valtype = -1;
++	void *vptr  = 0x0;
++	
++	// For keywords that require special handling.
++	int altlin  = 0;
++	char ptype  = ' ';
++	int (*chekval)(double) = 0x0;
++	int (*special)(double *, const double *) = 0x0;
++	struct auxprm *auxp = 0x0;
++	int naux = 0;
++	
 +	// Selection by column number.
- 	nsel = colsel ? colsel[0] : 0;
- 	incl = (nsel > 0);
- 	for (icol = 0; icol < 1000; icol++) {
-@@ -25981,7 +25978,7 @@ YY_DECL
++	int nsel = colsel ? colsel[0] : 0;
++	int incl = (nsel > 0);
++	char exclude[1000];
++	for (int icol = 0; icol < 1000; icol++) {
+ 	  exclude[icol] = incl;
+ 	}
+-	for (icol = 1; icol <= abs(nsel); icol++) {
+-	  itmp = colsel[icol];
++	for (int icol = 1; icol <= abs(nsel); icol++) {
++	  int itmp = colsel[icol];
+ 	  if (0 < itmp && itmp < 1000) {
+ 	    exclude[itmp] = !incl;
+ 	  }
  	}
  	exclude[0] = 0;
  	
 -	/* Selection by keyword type. */
+-	itmp = keysel;
+-	keysel = 0;
+-	if (itmp) {
 +	// Selection by keyword type.
- 	itmp = keysel;
- 	keysel = 0;
- 	if (itmp) {
-@@ -25993,11 +25990,11 @@ YY_DECL
++	if (keysel) {
++	  int itmp = keysel;
++	  keysel = 0;
+ 	  if (itmp & WCSHDR_IMGHEAD) keysel |= IMGHEAD;
+ 	  if (itmp & WCSHDR_BIMGARR) keysel |= BIMGARR;
+ 	  if (itmp & WCSHDR_PIXLIST) keysel |= PIXLIST;
+@@ -25993,19 +25948,23 @@ YY_DECL
  	  keysel = IMGHEAD | BINTAB;
  	}
  	
 -	/* Control variables. */
-+	// Control variables.
- 	ipass = 1;
- 	npass = 2;
- 	
+-	ipass = 1;
+-	npass = 2;
+-	
 -	/* Return here via longjmp() invoked by yy_fatal_error(). */
+-	if (setjmp(wcsbth_abort_jmp_env)) {
+-	  return 4;
++	// Control variables.
++	int ipass = 1;
++	int npass = 2;
++	
++	// User data associated with yyscanner.
++	yyextra->hdr = header;
++	yyextra->nkeyrec = nkeyrec;
++	
 +	// Return here via longjmp() invoked by yy_fatal_error().
- 	if (setjmp(wcsbth_abort_jmp_env)) {
- 	  return 4;
++	if (setjmp(yyextra->abort_jmp_env)) {
++	  return WCSHDRERR_PARSER;
  	}
-@@ -26005,7 +26002,7 @@ YY_DECL
+ 	
  	BEGIN(INITIAL);
  
  
 -#line 26009 "wcsbth.c"
-+#line 26006 "wcsbth.c"
++#line 25968 "wcsbth.c"
  
  	while ( /*CONSTCOND*/1 )		/* loops until end-of-file is reached */
  		{
-@@ -26053,7 +26050,7 @@ do_action:	/* This label is used only to
+@@ -26053,7 +26012,7 @@ do_action:	/* This label is used only to
  
  case 1:
  YY_RULE_SETUP
 -#line 366 "wcsbth.l"
-+#line 363 "wcsbth.l"
++#line 328 "wcsbth.l"
  {
  	  if (ipass == 1) {
  	    if (alts.ncol == 0) {
-@@ -26071,10 +26068,10 @@ YY_RULE_SETUP
+@@ -26071,10 +26030,10 @@ YY_RULE_SETUP
  	YY_BREAK
  case 2:
  YY_RULE_SETUP
 -#line 381 "wcsbth.l"
-+#line 378 "wcsbth.l"
++#line 343 "wcsbth.l"
  {
  	  if (!(keysel & IMGAXIS)) {
 -	    /* Ignore this key type. */
@@ -4778,7 +5696,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	    BEGIN(DISCARD);
  	
  	  } else {
-@@ -26099,28 +26096,28 @@ YY_RULE_SETUP
+@@ -26099,28 +26058,28 @@ YY_RULE_SETUP
  	      BEGIN(ERROR);
  	
  	    } else {
@@ -4791,14 +5709,14 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 3:
 -#line 415 "wcsbth.l"
-+#line 412 "wcsbth.l"
++#line 377 "wcsbth.l"
  case 4:
 -#line 416 "wcsbth.l"
-+#line 413 "wcsbth.l"
++#line 378 "wcsbth.l"
  case 5:
  YY_RULE_SETUP
 -#line 416 "wcsbth.l"
-+#line 413 "wcsbth.l"
++#line 378 "wcsbth.l"
  {
  	  keyname = "WCAXna";
  	
@@ -4814,735 +5732,735 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	    BEGIN(DISCARD);
  	
  	  } else if (i < 0) {
-@@ -26139,16 +26136,16 @@ YY_RULE_SETUP
+@@ -26139,16 +26098,16 @@ YY_RULE_SETUP
  	YY_BREAK
  case 6:
  /* rule 6 can match eol */
 -#line 442 "wcsbth.l"
-+#line 439 "wcsbth.l"
++#line 404 "wcsbth.l"
  case 7:
  /* rule 7 can match eol */
 -#line 443 "wcsbth.l"
-+#line 440 "wcsbth.l"
++#line 405 "wcsbth.l"
  case 8:
  /* rule 8 can match eol */
  YY_RULE_SETUP
 -#line 443 "wcsbth.l"
-+#line 440 "wcsbth.l"
++#line 405 "wcsbth.l"
  {
 -	  /* Cross-reference supplier. */
 +	  // Cross-reference supplier.
  	  keyname = "WCSTna";
  	  errmsg = "cross-references are not implemented";
  	  BEGIN(ERROR);
-@@ -26156,16 +26153,16 @@ YY_RULE_SETUP
+@@ -26156,16 +26115,16 @@ YY_RULE_SETUP
  	YY_BREAK
  case 9:
  /* rule 9 can match eol */
 -#line 451 "wcsbth.l"
-+#line 448 "wcsbth.l"
++#line 413 "wcsbth.l"
  case 10:
  /* rule 10 can match eol */
 -#line 452 "wcsbth.l"
-+#line 449 "wcsbth.l"
++#line 414 "wcsbth.l"
  case 11:
  /* rule 11 can match eol */
  YY_RULE_SETUP
 -#line 452 "wcsbth.l"
-+#line 449 "wcsbth.l"
++#line 414 "wcsbth.l"
  {
 -	  /* Cross-reference consumer. */
 +	  // Cross-reference consumer.
  	  keyname = "WCSXna";
  	  errmsg = "cross-references are not implemented";
  	  BEGIN(ERROR);
-@@ -26173,7 +26170,7 @@ YY_RULE_SETUP
+@@ -26173,7 +26132,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 12:
  YY_RULE_SETUP
 -#line 459 "wcsbth.l"
-+#line 456 "wcsbth.l"
++#line 421 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.crpix);
-@@ -26183,10 +26180,10 @@ YY_RULE_SETUP
+@@ -26183,10 +26142,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 13:
 -#line 468 "wcsbth.l"
-+#line 465 "wcsbth.l"
++#line 430 "wcsbth.l"
  case 14:
  YY_RULE_SETUP
 -#line 468 "wcsbth.l"
-+#line 465 "wcsbth.l"
++#line 430 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.crpix);
-@@ -26203,10 +26200,10 @@ YY_RULE_SETUP
+@@ -26203,10 +26162,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 15:
 -#line 484 "wcsbth.l"
-+#line 481 "wcsbth.l"
++#line 446 "wcsbth.l"
  case 16:
  YY_RULE_SETUP
 -#line 484 "wcsbth.l"
-+#line 481 "wcsbth.l"
++#line 446 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.crpix);
-@@ -26222,7 +26219,7 @@ YY_RULE_SETUP
+@@ -26222,7 +26181,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 17:
  YY_RULE_SETUP
 -#line 497 "wcsbth.l"
-+#line 494 "wcsbth.l"
++#line 459 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.pc);
-@@ -26234,7 +26231,7 @@ YY_RULE_SETUP
+@@ -26234,7 +26193,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 18:
  YY_RULE_SETUP
 -#line 506 "wcsbth.l"
-+#line 503 "wcsbth.l"
++#line 468 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.pc);
-@@ -26247,10 +26244,10 @@ YY_RULE_SETUP
+@@ -26247,10 +26206,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 19:
 -#line 518 "wcsbth.l"
-+#line 515 "wcsbth.l"
++#line 480 "wcsbth.l"
  case 20:
  YY_RULE_SETUP
 -#line 518 "wcsbth.l"
-+#line 515 "wcsbth.l"
++#line 480 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.pc);
-@@ -26267,7 +26264,7 @@ YY_RULE_SETUP
+@@ -26267,7 +26226,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 21:
  YY_RULE_SETUP
 -#line 532 "wcsbth.l"
-+#line 529 "wcsbth.l"
++#line 494 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.cd);
-@@ -26279,7 +26276,7 @@ YY_RULE_SETUP
+@@ -26279,7 +26238,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 22:
  YY_RULE_SETUP
 -#line 541 "wcsbth.l"
-+#line 538 "wcsbth.l"
++#line 503 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.cd);
-@@ -26292,10 +26289,10 @@ YY_RULE_SETUP
+@@ -26292,10 +26251,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 23:
 -#line 553 "wcsbth.l"
-+#line 550 "wcsbth.l"
++#line 515 "wcsbth.l"
  case 24:
  YY_RULE_SETUP
 -#line 553 "wcsbth.l"
-+#line 550 "wcsbth.l"
++#line 515 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.cd);
-@@ -26312,7 +26309,7 @@ YY_RULE_SETUP
+@@ -26312,7 +26271,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 25:
  YY_RULE_SETUP
 -#line 567 "wcsbth.l"
-+#line 564 "wcsbth.l"
++#line 529 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.cdelt);
-@@ -26322,10 +26319,10 @@ YY_RULE_SETUP
+@@ -26322,10 +26281,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 26:
 -#line 576 "wcsbth.l"
-+#line 573 "wcsbth.l"
++#line 538 "wcsbth.l"
  case 27:
  YY_RULE_SETUP
 -#line 576 "wcsbth.l"
-+#line 573 "wcsbth.l"
++#line 538 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.cdelt);
-@@ -26342,10 +26339,10 @@ YY_RULE_SETUP
+@@ -26342,10 +26301,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 28:
 -#line 592 "wcsbth.l"
-+#line 589 "wcsbth.l"
++#line 554 "wcsbth.l"
  case 29:
  YY_RULE_SETUP
 -#line 592 "wcsbth.l"
-+#line 589 "wcsbth.l"
++#line 554 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.cdelt);
-@@ -26361,7 +26358,7 @@ YY_RULE_SETUP
+@@ -26361,7 +26320,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 30:
  YY_RULE_SETUP
 -#line 605 "wcsbth.l"
-+#line 602 "wcsbth.l"
++#line 567 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.crota);
-@@ -26373,7 +26370,7 @@ YY_RULE_SETUP
+@@ -26373,7 +26332,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 31:
  YY_RULE_SETUP
 -#line 614 "wcsbth.l"
-+#line 611 "wcsbth.l"
++#line 576 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.crota);
-@@ -26387,7 +26384,7 @@ YY_RULE_SETUP
+@@ -26387,7 +26346,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 32:
  YY_RULE_SETUP
 -#line 625 "wcsbth.l"
-+#line 622 "wcsbth.l"
++#line 587 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.crota);
-@@ -26399,7 +26396,7 @@ YY_RULE_SETUP
+@@ -26399,7 +26358,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 33:
  YY_RULE_SETUP
 -#line 634 "wcsbth.l"
-+#line 631 "wcsbth.l"
++#line 596 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = &(wcstem.cunit);
-@@ -26409,10 +26406,10 @@ YY_RULE_SETUP
+@@ -26409,10 +26368,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 34:
 -#line 643 "wcsbth.l"
-+#line 640 "wcsbth.l"
++#line 605 "wcsbth.l"
  case 35:
  YY_RULE_SETUP
 -#line 643 "wcsbth.l"
-+#line 640 "wcsbth.l"
++#line 605 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = &(wcstem.cunit);
-@@ -26429,10 +26426,10 @@ YY_RULE_SETUP
+@@ -26429,10 +26388,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 36:
 -#line 659 "wcsbth.l"
-+#line 656 "wcsbth.l"
++#line 621 "wcsbth.l"
  case 37:
  YY_RULE_SETUP
 -#line 659 "wcsbth.l"
-+#line 656 "wcsbth.l"
++#line 621 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = &(wcstem.cunit);
-@@ -26448,7 +26445,7 @@ YY_RULE_SETUP
+@@ -26448,7 +26407,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 38:
  YY_RULE_SETUP
 -#line 672 "wcsbth.l"
-+#line 669 "wcsbth.l"
++#line 634 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = &(wcstem.ctype);
-@@ -26458,10 +26455,10 @@ YY_RULE_SETUP
+@@ -26458,10 +26417,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 39:
 -#line 681 "wcsbth.l"
-+#line 678 "wcsbth.l"
++#line 643 "wcsbth.l"
  case 40:
  YY_RULE_SETUP
 -#line 681 "wcsbth.l"
-+#line 678 "wcsbth.l"
++#line 643 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = &(wcstem.ctype);
-@@ -26478,10 +26475,10 @@ YY_RULE_SETUP
+@@ -26478,10 +26437,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 41:
 -#line 697 "wcsbth.l"
-+#line 694 "wcsbth.l"
++#line 659 "wcsbth.l"
  case 42:
  YY_RULE_SETUP
 -#line 697 "wcsbth.l"
-+#line 694 "wcsbth.l"
++#line 659 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = &(wcstem.ctype);
-@@ -26497,7 +26494,7 @@ YY_RULE_SETUP
+@@ -26497,7 +26456,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 43:
  YY_RULE_SETUP
 -#line 710 "wcsbth.l"
-+#line 707 "wcsbth.l"
++#line 672 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.crval);
-@@ -26507,10 +26504,10 @@ YY_RULE_SETUP
+@@ -26507,10 +26466,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 44:
 -#line 719 "wcsbth.l"
-+#line 716 "wcsbth.l"
++#line 681 "wcsbth.l"
  case 45:
  YY_RULE_SETUP
 -#line 719 "wcsbth.l"
-+#line 716 "wcsbth.l"
++#line 681 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.crval);
-@@ -26527,10 +26524,10 @@ YY_RULE_SETUP
+@@ -26527,10 +26486,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 46:
 -#line 735 "wcsbth.l"
-+#line 732 "wcsbth.l"
++#line 697 "wcsbth.l"
  case 47:
  YY_RULE_SETUP
 -#line 735 "wcsbth.l"
-+#line 732 "wcsbth.l"
++#line 697 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.crval);
-@@ -26545,10 +26542,10 @@ YY_RULE_SETUP
+@@ -26545,10 +26504,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 48:
 -#line 749 "wcsbth.l"
-+#line 746 "wcsbth.l"
++#line 711 "wcsbth.l"
  case 49:
  YY_RULE_SETUP
 -#line 749 "wcsbth.l"
-+#line 746 "wcsbth.l"
++#line 711 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.lonpole);
-@@ -26564,10 +26561,10 @@ YY_RULE_SETUP
+@@ -26564,10 +26523,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 50:
 -#line 764 "wcsbth.l"
-+#line 761 "wcsbth.l"
++#line 726 "wcsbth.l"
  case 51:
  YY_RULE_SETUP
 -#line 764 "wcsbth.l"
-+#line 761 "wcsbth.l"
++#line 726 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.latpole);
-@@ -26583,12 +26580,12 @@ YY_RULE_SETUP
+@@ -26583,12 +26542,12 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 52:
 -#line 779 "wcsbth.l"
-+#line 776 "wcsbth.l"
++#line 741 "wcsbth.l"
  case 53:
 -#line 780 "wcsbth.l"
-+#line 777 "wcsbth.l"
++#line 742 "wcsbth.l"
  case 54:
  YY_RULE_SETUP
 -#line 780 "wcsbth.l"
-+#line 777 "wcsbth.l"
++#line 742 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.restfrq);
-@@ -26616,10 +26613,10 @@ YY_RULE_SETUP
+@@ -26616,10 +26575,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 55:
 -#line 807 "wcsbth.l"
-+#line 804 "wcsbth.l"
++#line 769 "wcsbth.l"
  case 56:
  YY_RULE_SETUP
 -#line 807 "wcsbth.l"
-+#line 804 "wcsbth.l"
++#line 769 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.restwav);
-@@ -26635,7 +26632,7 @@ YY_RULE_SETUP
+@@ -26635,7 +26594,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 57:
  YY_RULE_SETUP
 -#line 820 "wcsbth.l"
-+#line 817 "wcsbth.l"
++#line 782 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.pv);
-@@ -26646,10 +26643,10 @@ YY_RULE_SETUP
+@@ -26646,10 +26605,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 58:
 -#line 830 "wcsbth.l"
-+#line 827 "wcsbth.l"
++#line 792 "wcsbth.l"
  case 59:
  YY_RULE_SETUP
 -#line 830 "wcsbth.l"
-+#line 827 "wcsbth.l"
++#line 792 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.pv);
-@@ -26667,10 +26664,10 @@ YY_RULE_SETUP
+@@ -26667,10 +26626,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 60:
 -#line 847 "wcsbth.l"
-+#line 844 "wcsbth.l"
++#line 809 "wcsbth.l"
  case 61:
  YY_RULE_SETUP
 -#line 847 "wcsbth.l"
-+#line 844 "wcsbth.l"
++#line 809 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.pv);
-@@ -26687,7 +26684,7 @@ YY_RULE_SETUP
+@@ -26687,7 +26646,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 62:
  YY_RULE_SETUP
 -#line 861 "wcsbth.l"
-+#line 858 "wcsbth.l"
++#line 823 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.pv);
-@@ -26699,7 +26696,7 @@ YY_RULE_SETUP
+@@ -26699,7 +26658,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 63:
  YY_RULE_SETUP
 -#line 870 "wcsbth.l"
-+#line 867 "wcsbth.l"
++#line 832 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = &(wcstem.ps);
-@@ -26710,10 +26707,10 @@ YY_RULE_SETUP
+@@ -26710,10 +26669,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 64:
 -#line 880 "wcsbth.l"
-+#line 877 "wcsbth.l"
++#line 842 "wcsbth.l"
  case 65:
  YY_RULE_SETUP
 -#line 880 "wcsbth.l"
-+#line 877 "wcsbth.l"
++#line 842 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = &(wcstem.ps);
-@@ -26731,10 +26728,10 @@ YY_RULE_SETUP
+@@ -26731,10 +26690,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 66:
 -#line 897 "wcsbth.l"
-+#line 894 "wcsbth.l"
++#line 859 "wcsbth.l"
  case 67:
  YY_RULE_SETUP
 -#line 897 "wcsbth.l"
-+#line 894 "wcsbth.l"
++#line 859 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = &(wcstem.ps);
-@@ -26751,7 +26748,7 @@ YY_RULE_SETUP
+@@ -26751,7 +26710,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 68:
  YY_RULE_SETUP
 -#line 911 "wcsbth.l"
-+#line 908 "wcsbth.l"
++#line 873 "wcsbth.l"
  {
  	  sscanf(yytext, "VELREF%c", &a);
  	
-@@ -26780,7 +26777,7 @@ YY_RULE_SETUP
+@@ -26780,7 +26739,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 69:
  YY_RULE_SETUP
 -#line 937 "wcsbth.l"
-+#line 934 "wcsbth.l"
++#line 899 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = &(wcstem.cname);
-@@ -26790,10 +26787,10 @@ YY_RULE_SETUP
+@@ -26790,10 +26749,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 70:
 -#line 946 "wcsbth.l"
-+#line 943 "wcsbth.l"
++#line 908 "wcsbth.l"
  case 71:
  YY_RULE_SETUP
 -#line 946 "wcsbth.l"
-+#line 943 "wcsbth.l"
++#line 908 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = &(wcstem.cname);
-@@ -26811,10 +26808,10 @@ YY_RULE_SETUP
+@@ -26811,10 +26770,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 72:
 -#line 963 "wcsbth.l"
-+#line 960 "wcsbth.l"
++#line 925 "wcsbth.l"
  case 73:
  YY_RULE_SETUP
 -#line 963 "wcsbth.l"
-+#line 960 "wcsbth.l"
++#line 925 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = &(wcstem.cname);
-@@ -26831,7 +26828,7 @@ YY_RULE_SETUP
+@@ -26831,7 +26790,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 74:
  YY_RULE_SETUP
 -#line 977 "wcsbth.l"
-+#line 974 "wcsbth.l"
++#line 939 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.crder);
-@@ -26841,10 +26838,10 @@ YY_RULE_SETUP
+@@ -26841,10 +26800,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 75:
 -#line 986 "wcsbth.l"
-+#line 983 "wcsbth.l"
++#line 948 "wcsbth.l"
  case 76:
  YY_RULE_SETUP
 -#line 986 "wcsbth.l"
-+#line 983 "wcsbth.l"
++#line 948 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.crder);
-@@ -26862,10 +26859,10 @@ YY_RULE_SETUP
+@@ -26862,10 +26821,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 77:
 -#line 1003 "wcsbth.l"
-+#line 1000 "wcsbth.l"
++#line 965 "wcsbth.l"
  case 78:
  YY_RULE_SETUP
 -#line 1003 "wcsbth.l"
-+#line 1000 "wcsbth.l"
++#line 965 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.crder);
-@@ -26882,7 +26879,7 @@ YY_RULE_SETUP
+@@ -26882,7 +26841,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 79:
  YY_RULE_SETUP
 -#line 1017 "wcsbth.l"
-+#line 1014 "wcsbth.l"
++#line 979 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.csyer);
-@@ -26892,10 +26889,10 @@ YY_RULE_SETUP
+@@ -26892,10 +26851,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 80:
 -#line 1026 "wcsbth.l"
-+#line 1023 "wcsbth.l"
++#line 988 "wcsbth.l"
  case 81:
  YY_RULE_SETUP
 -#line 1026 "wcsbth.l"
-+#line 1023 "wcsbth.l"
++#line 988 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.csyer);
-@@ -26913,10 +26910,10 @@ YY_RULE_SETUP
+@@ -26913,10 +26872,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 82:
 -#line 1043 "wcsbth.l"
-+#line 1040 "wcsbth.l"
++#line 1005 "wcsbth.l"
  case 83:
  YY_RULE_SETUP
 -#line 1043 "wcsbth.l"
-+#line 1040 "wcsbth.l"
++#line 1005 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.csyer);
-@@ -26933,7 +26930,7 @@ YY_RULE_SETUP
+@@ -26933,7 +26892,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 84:
  YY_RULE_SETUP
 -#line 1057 "wcsbth.l"
-+#line 1054 "wcsbth.l"
++#line 1019 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.czphs);
-@@ -26943,10 +26940,10 @@ YY_RULE_SETUP
+@@ -26943,10 +26902,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 85:
 -#line 1066 "wcsbth.l"
-+#line 1063 "wcsbth.l"
++#line 1028 "wcsbth.l"
  case 86:
  YY_RULE_SETUP
 -#line 1066 "wcsbth.l"
-+#line 1063 "wcsbth.l"
++#line 1028 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.czphs);
-@@ -26964,10 +26961,10 @@ YY_RULE_SETUP
+@@ -26964,10 +26923,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 87:
 -#line 1083 "wcsbth.l"
-+#line 1080 "wcsbth.l"
++#line 1045 "wcsbth.l"
  case 88:
  YY_RULE_SETUP
 -#line 1083 "wcsbth.l"
-+#line 1080 "wcsbth.l"
++#line 1045 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.czphs);
-@@ -26984,7 +26981,7 @@ YY_RULE_SETUP
+@@ -26984,7 +26943,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 89:
  YY_RULE_SETUP
 -#line 1097 "wcsbth.l"
-+#line 1094 "wcsbth.l"
++#line 1059 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.cperi);
-@@ -26994,10 +26991,10 @@ YY_RULE_SETUP
+@@ -26994,10 +26953,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 90:
 -#line 1106 "wcsbth.l"
-+#line 1103 "wcsbth.l"
++#line 1068 "wcsbth.l"
  case 91:
  YY_RULE_SETUP
 -#line 1106 "wcsbth.l"
-+#line 1103 "wcsbth.l"
++#line 1068 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.cperi);
-@@ -27015,10 +27012,10 @@ YY_RULE_SETUP
+@@ -27015,10 +26974,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 92:
 -#line 1123 "wcsbth.l"
-+#line 1120 "wcsbth.l"
++#line 1085 "wcsbth.l"
  case 93:
  YY_RULE_SETUP
 -#line 1123 "wcsbth.l"
-+#line 1120 "wcsbth.l"
++#line 1085 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.cperi);
-@@ -27034,12 +27031,12 @@ YY_RULE_SETUP
+@@ -27034,12 +26993,12 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 94:
 -#line 1138 "wcsbth.l"
-+#line 1135 "wcsbth.l"
++#line 1100 "wcsbth.l"
  case 95:
 -#line 1139 "wcsbth.l"
-+#line 1136 "wcsbth.l"
++#line 1101 "wcsbth.l"
  case 96:
  YY_RULE_SETUP
 -#line 1139 "wcsbth.l"
-+#line 1136 "wcsbth.l"
++#line 1101 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.wcsname;
-@@ -27061,7 +27058,7 @@ YY_RULE_SETUP
+@@ -27061,7 +27020,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 97:
  YY_RULE_SETUP
 -#line 1158 "wcsbth.l"
-+#line 1155 "wcsbth.l"
++#line 1120 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.timesys;
-@@ -27071,10 +27068,10 @@ YY_RULE_SETUP
+@@ -27071,10 +27030,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 98:
 -#line 1167 "wcsbth.l"
-+#line 1164 "wcsbth.l"
++#line 1129 "wcsbth.l"
  case 99:
  YY_RULE_SETUP
 -#line 1167 "wcsbth.l"
-+#line 1164 "wcsbth.l"
++#line 1129 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.trefpos;
-@@ -27090,10 +27087,10 @@ YY_RULE_SETUP
+@@ -27090,10 +27049,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 100:
 -#line 1182 "wcsbth.l"
-+#line 1179 "wcsbth.l"
++#line 1144 "wcsbth.l"
  case 101:
  YY_RULE_SETUP
 -#line 1182 "wcsbth.l"
-+#line 1179 "wcsbth.l"
++#line 1144 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.trefdir;
-@@ -27110,7 +27107,7 @@ YY_RULE_SETUP
+@@ -27110,7 +27069,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 102:
  YY_RULE_SETUP
 -#line 1196 "wcsbth.l"
-+#line 1193 "wcsbth.l"
++#line 1158 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.plephem;
-@@ -27121,7 +27118,7 @@ YY_RULE_SETUP
+@@ -27121,7 +27080,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 103:
  YY_RULE_SETUP
 -#line 1204 "wcsbth.l"
-+#line 1201 "wcsbth.l"
++#line 1166 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.timeunit;
-@@ -27131,10 +27128,10 @@ YY_RULE_SETUP
+@@ -27131,10 +27090,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 104:
 -#line 1213 "wcsbth.l"
-+#line 1210 "wcsbth.l"
++#line 1175 "wcsbth.l"
  case 105:
  YY_RULE_SETUP
 -#line 1213 "wcsbth.l"
-+#line 1210 "wcsbth.l"
++#line 1175 "wcsbth.l"
  {
  	  if ((yytext[4] == 'R') || (relax & WCSHDR_DATEREF)) {
  	    valtype = STRING;
-@@ -27153,10 +27150,10 @@ YY_RULE_SETUP
+@@ -27153,10 +27112,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 106:
 -#line 1231 "wcsbth.l"
-+#line 1228 "wcsbth.l"
++#line 1193 "wcsbth.l"
  case 107:
  YY_RULE_SETUP
 -#line 1231 "wcsbth.l"
-+#line 1228 "wcsbth.l"
++#line 1193 "wcsbth.l"
  {
  	  if ((yytext[3] == 'R') || (relax & WCSHDR_DATEREF)) {
  	    valtype = FLOAT2;
-@@ -27175,13 +27172,13 @@ YY_RULE_SETUP
+@@ -27175,13 +27134,13 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 108:
 -#line 1249 "wcsbth.l"
-+#line 1246 "wcsbth.l"
++#line 1211 "wcsbth.l"
  case 109:
  YY_RULE_SETUP
 -#line 1249 "wcsbth.l"
-+#line 1246 "wcsbth.l"
++#line 1211 "wcsbth.l"
  {
  	  if ((yytext[3] == 'R') || (relax & WCSHDR_DATEREF)) {
 -	    /* Actually integer, but treated as float. */
@@ -5550,42 +6468,42 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	    valtype = FLOAT;
  	    vptr    = wcstem.mjdref;
  	
-@@ -27198,10 +27195,10 @@ YY_RULE_SETUP
+@@ -27198,10 +27157,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 110:
 -#line 1268 "wcsbth.l"
-+#line 1265 "wcsbth.l"
++#line 1230 "wcsbth.l"
  case 111:
  YY_RULE_SETUP
 -#line 1268 "wcsbth.l"
-+#line 1265 "wcsbth.l"
++#line 1230 "wcsbth.l"
  {
  	  if ((yytext[3] == 'R') || (relax & WCSHDR_DATEREF)) {
  	    valtype = FLOAT;
-@@ -27220,10 +27217,10 @@ YY_RULE_SETUP
+@@ -27220,10 +27179,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 112:
 -#line 1286 "wcsbth.l"
-+#line 1283 "wcsbth.l"
++#line 1248 "wcsbth.l"
  case 113:
  YY_RULE_SETUP
 -#line 1286 "wcsbth.l"
-+#line 1283 "wcsbth.l"
++#line 1248 "wcsbth.l"
  {
  	  if ((yytext[2] == 'R') || (relax & WCSHDR_DATEREF)) {
  	    valtype = FLOAT2;
-@@ -27243,13 +27240,13 @@ YY_RULE_SETUP
+@@ -27243,13 +27202,13 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 114:
 -#line 1305 "wcsbth.l"
-+#line 1302 "wcsbth.l"
++#line 1267 "wcsbth.l"
  case 115:
  YY_RULE_SETUP
 -#line 1305 "wcsbth.l"
-+#line 1302 "wcsbth.l"
++#line 1267 "wcsbth.l"
  {
  	  if ((yytext[2] == 'R') || (relax & WCSHDR_DATEREF)) {
 -	    /* Actually integer, but treated as float. */
@@ -5593,450 +6511,450 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	    valtype = FLOAT;
  	    vptr    = wcstem.mjdref;
  	    special = wcsbth_jdrefi;
-@@ -27267,10 +27264,10 @@ YY_RULE_SETUP
+@@ -27267,10 +27226,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 116:
 -#line 1325 "wcsbth.l"
-+#line 1322 "wcsbth.l"
++#line 1287 "wcsbth.l"
  case 117:
  YY_RULE_SETUP
 -#line 1325 "wcsbth.l"
-+#line 1322 "wcsbth.l"
++#line 1287 "wcsbth.l"
  {
  	  if ((yytext[2] == 'R') || (relax & WCSHDR_DATEREF)) {
  	    valtype = FLOAT;
-@@ -27291,7 +27288,7 @@ YY_RULE_SETUP
+@@ -27291,7 +27250,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 118:
  YY_RULE_SETUP
 -#line 1343 "wcsbth.l"
-+#line 1340 "wcsbth.l"
++#line 1305 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.timeoffs);
-@@ -27302,7 +27299,7 @@ YY_RULE_SETUP
+@@ -27302,7 +27261,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 119:
  YY_RULE_SETUP
 -#line 1351 "wcsbth.l"
-+#line 1348 "wcsbth.l"
++#line 1313 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.dateobs;
-@@ -27314,12 +27311,12 @@ YY_RULE_SETUP
+@@ -27314,12 +27273,12 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 120:
 -#line 1362 "wcsbth.l"
-+#line 1359 "wcsbth.l"
++#line 1324 "wcsbth.l"
  case 121:
 -#line 1363 "wcsbth.l"
-+#line 1360 "wcsbth.l"
++#line 1325 "wcsbth.l"
  case 122:
  YY_RULE_SETUP
 -#line 1363 "wcsbth.l"
-+#line 1360 "wcsbth.l"
++#line 1325 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.dateobs;
-@@ -27341,7 +27338,7 @@ YY_RULE_SETUP
+@@ -27341,7 +27300,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 123:
  YY_RULE_SETUP
 -#line 1382 "wcsbth.l"
-+#line 1379 "wcsbth.l"
++#line 1344 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.datebeg;
-@@ -27352,10 +27349,10 @@ YY_RULE_SETUP
+@@ -27352,10 +27311,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 124:
 -#line 1392 "wcsbth.l"
-+#line 1389 "wcsbth.l"
++#line 1354 "wcsbth.l"
  case 125:
  YY_RULE_SETUP
 -#line 1392 "wcsbth.l"
-+#line 1389 "wcsbth.l"
++#line 1354 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.dateavg;
-@@ -27372,7 +27369,7 @@ YY_RULE_SETUP
+@@ -27372,7 +27331,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 126:
  YY_RULE_SETUP
 -#line 1406 "wcsbth.l"
-+#line 1403 "wcsbth.l"
++#line 1368 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.dateend;
-@@ -27383,10 +27380,10 @@ YY_RULE_SETUP
+@@ -27383,10 +27342,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 127:
 -#line 1416 "wcsbth.l"
-+#line 1413 "wcsbth.l"
++#line 1378 "wcsbth.l"
  case 128:
  YY_RULE_SETUP
 -#line 1416 "wcsbth.l"
-+#line 1413 "wcsbth.l"
++#line 1378 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.mjdobs);
-@@ -27404,7 +27401,7 @@ YY_RULE_SETUP
+@@ -27404,7 +27363,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 129:
  YY_RULE_SETUP
 -#line 1431 "wcsbth.l"
-+#line 1428 "wcsbth.l"
++#line 1393 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.mjdbeg);
-@@ -27415,10 +27412,10 @@ YY_RULE_SETUP
+@@ -27415,10 +27374,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 130:
 -#line 1441 "wcsbth.l"
-+#line 1438 "wcsbth.l"
++#line 1403 "wcsbth.l"
  case 131:
  YY_RULE_SETUP
 -#line 1441 "wcsbth.l"
-+#line 1438 "wcsbth.l"
++#line 1403 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.mjdavg);
-@@ -27435,7 +27432,7 @@ YY_RULE_SETUP
+@@ -27435,7 +27394,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 132:
  YY_RULE_SETUP
 -#line 1455 "wcsbth.l"
-+#line 1452 "wcsbth.l"
++#line 1417 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.mjdend);
-@@ -27447,7 +27444,7 @@ YY_RULE_SETUP
+@@ -27447,7 +27406,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 133:
  YY_RULE_SETUP
 -#line 1464 "wcsbth.l"
-+#line 1461 "wcsbth.l"
++#line 1426 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.jepoch);
-@@ -27459,7 +27456,7 @@ YY_RULE_SETUP
+@@ -27459,7 +27418,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 134:
  YY_RULE_SETUP
 -#line 1473 "wcsbth.l"
-+#line 1470 "wcsbth.l"
++#line 1435 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.bepoch);
-@@ -27471,7 +27468,7 @@ YY_RULE_SETUP
+@@ -27471,7 +27430,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 135:
  YY_RULE_SETUP
 -#line 1482 "wcsbth.l"
-+#line 1479 "wcsbth.l"
++#line 1444 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.tstart);
-@@ -27483,7 +27480,7 @@ YY_RULE_SETUP
+@@ -27483,7 +27442,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 136:
  YY_RULE_SETUP
 -#line 1491 "wcsbth.l"
-+#line 1488 "wcsbth.l"
++#line 1453 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.tstop);
-@@ -27495,7 +27492,7 @@ YY_RULE_SETUP
+@@ -27495,7 +27454,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 137:
  YY_RULE_SETUP
 -#line 1500 "wcsbth.l"
-+#line 1497 "wcsbth.l"
++#line 1462 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.xposure);
-@@ -27507,7 +27504,7 @@ YY_RULE_SETUP
+@@ -27507,7 +27466,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 138:
  YY_RULE_SETUP
 -#line 1509 "wcsbth.l"
-+#line 1506 "wcsbth.l"
++#line 1471 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.telapse);
-@@ -27519,7 +27516,7 @@ YY_RULE_SETUP
+@@ -27519,7 +27478,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 139:
  YY_RULE_SETUP
 -#line 1518 "wcsbth.l"
-+#line 1515 "wcsbth.l"
++#line 1480 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.timsyer);
-@@ -27531,7 +27528,7 @@ YY_RULE_SETUP
+@@ -27531,7 +27490,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 140:
  YY_RULE_SETUP
 -#line 1527 "wcsbth.l"
-+#line 1524 "wcsbth.l"
++#line 1489 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.timrder);
-@@ -27543,7 +27540,7 @@ YY_RULE_SETUP
+@@ -27543,7 +27502,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 141:
  YY_RULE_SETUP
 -#line 1536 "wcsbth.l"
-+#line 1533 "wcsbth.l"
++#line 1498 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.timedel);
-@@ -27555,7 +27552,7 @@ YY_RULE_SETUP
+@@ -27555,7 +27514,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 142:
  YY_RULE_SETUP
 -#line 1545 "wcsbth.l"
-+#line 1542 "wcsbth.l"
++#line 1507 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.timepixr);
-@@ -27567,10 +27564,10 @@ YY_RULE_SETUP
+@@ -27567,10 +27526,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 143:
 -#line 1556 "wcsbth.l"
-+#line 1553 "wcsbth.l"
++#line 1518 "wcsbth.l"
  case 144:
  YY_RULE_SETUP
 -#line 1556 "wcsbth.l"
-+#line 1553 "wcsbth.l"
++#line 1518 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = wcstem.obsgeo;
-@@ -27586,10 +27583,10 @@ YY_RULE_SETUP
+@@ -27586,10 +27545,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 145:
 -#line 1571 "wcsbth.l"
-+#line 1568 "wcsbth.l"
++#line 1533 "wcsbth.l"
  case 146:
  YY_RULE_SETUP
 -#line 1571 "wcsbth.l"
-+#line 1568 "wcsbth.l"
++#line 1533 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = wcstem.obsgeo + 1;
-@@ -27605,10 +27602,10 @@ YY_RULE_SETUP
+@@ -27605,10 +27564,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 147:
 -#line 1586 "wcsbth.l"
-+#line 1583 "wcsbth.l"
++#line 1548 "wcsbth.l"
  case 148:
  YY_RULE_SETUP
 -#line 1586 "wcsbth.l"
-+#line 1583 "wcsbth.l"
++#line 1548 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = wcstem.obsgeo + 2;
-@@ -27625,7 +27622,7 @@ YY_RULE_SETUP
+@@ -27625,7 +27584,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 149:
  YY_RULE_SETUP
 -#line 1600 "wcsbth.l"
-+#line 1597 "wcsbth.l"
++#line 1562 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = wcstem.obsgeo + 3;
-@@ -27636,12 +27633,12 @@ YY_RULE_SETUP
+@@ -27636,12 +27595,12 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 150:
 -#line 1610 "wcsbth.l"
-+#line 1607 "wcsbth.l"
++#line 1572 "wcsbth.l"
  case 151:
 -#line 1611 "wcsbth.l"
-+#line 1608 "wcsbth.l"
++#line 1573 "wcsbth.l"
  case 152:
  YY_RULE_SETUP
 -#line 1611 "wcsbth.l"
-+#line 1608 "wcsbth.l"
++#line 1573 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.obsgeo + 3;
-@@ -27663,7 +27660,7 @@ YY_RULE_SETUP
+@@ -27663,7 +27622,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 153:
  YY_RULE_SETUP
 -#line 1630 "wcsbth.l"
-+#line 1627 "wcsbth.l"
++#line 1592 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = wcstem.obsgeo + 4;
-@@ -27674,12 +27671,12 @@ YY_RULE_SETUP
+@@ -27674,12 +27633,12 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 154:
 -#line 1640 "wcsbth.l"
-+#line 1637 "wcsbth.l"
++#line 1602 "wcsbth.l"
  case 155:
 -#line 1641 "wcsbth.l"
-+#line 1638 "wcsbth.l"
++#line 1603 "wcsbth.l"
  case 156:
  YY_RULE_SETUP
 -#line 1641 "wcsbth.l"
-+#line 1638 "wcsbth.l"
++#line 1603 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.obsgeo + 3;
-@@ -27701,7 +27698,7 @@ YY_RULE_SETUP
+@@ -27701,7 +27660,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 157:
  YY_RULE_SETUP
 -#line 1660 "wcsbth.l"
-+#line 1657 "wcsbth.l"
++#line 1622 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = wcstem.obsgeo + 5;
-@@ -27712,12 +27709,12 @@ YY_RULE_SETUP
+@@ -27712,12 +27671,12 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 158:
 -#line 1670 "wcsbth.l"
-+#line 1667 "wcsbth.l"
++#line 1632 "wcsbth.l"
  case 159:
 -#line 1671 "wcsbth.l"
-+#line 1668 "wcsbth.l"
++#line 1633 "wcsbth.l"
  case 160:
  YY_RULE_SETUP
 -#line 1671 "wcsbth.l"
-+#line 1668 "wcsbth.l"
++#line 1633 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.obsgeo + 3;
-@@ -27739,7 +27736,7 @@ YY_RULE_SETUP
+@@ -27739,7 +27698,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 161:
  YY_RULE_SETUP
 -#line 1690 "wcsbth.l"
-+#line 1687 "wcsbth.l"
++#line 1652 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.obsorbit;
-@@ -27749,10 +27746,10 @@ YY_RULE_SETUP
+@@ -27749,10 +27708,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 162:
 -#line 1699 "wcsbth.l"
-+#line 1696 "wcsbth.l"
++#line 1661 "wcsbth.l"
  case 163:
  YY_RULE_SETUP
 -#line 1699 "wcsbth.l"
-+#line 1696 "wcsbth.l"
++#line 1661 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.radesys;
-@@ -27769,7 +27766,7 @@ YY_RULE_SETUP
+@@ -27769,7 +27728,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 164:
  YY_RULE_SETUP
 -#line 1713 "wcsbth.l"
-+#line 1710 "wcsbth.l"
++#line 1675 "wcsbth.l"
  {
  	  if (relax & WCSHDR_RADECSYS) {
  	    valtype = STRING;
-@@ -27792,7 +27789,7 @@ YY_RULE_SETUP
+@@ -27792,7 +27751,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 165:
  YY_RULE_SETUP
 -#line 1733 "wcsbth.l"
-+#line 1730 "wcsbth.l"
++#line 1695 "wcsbth.l"
  {
  	  sscanf(yytext, "EPOCH%c", &a);
  	
-@@ -27821,10 +27818,10 @@ YY_RULE_SETUP
+@@ -27821,10 +27780,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 166:
 -#line 1761 "wcsbth.l"
-+#line 1758 "wcsbth.l"
++#line 1723 "wcsbth.l"
  case 167:
  YY_RULE_SETUP
 -#line 1761 "wcsbth.l"
-+#line 1758 "wcsbth.l"
++#line 1723 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.equinox);
-@@ -27840,10 +27837,10 @@ YY_RULE_SETUP
+@@ -27840,10 +27799,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 168:
 -#line 1776 "wcsbth.l"
-+#line 1773 "wcsbth.l"
++#line 1738 "wcsbth.l"
  case 169:
  YY_RULE_SETUP
 -#line 1776 "wcsbth.l"
-+#line 1773 "wcsbth.l"
++#line 1738 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.specsys;
-@@ -27858,10 +27855,10 @@ YY_RULE_SETUP
+@@ -27858,10 +27817,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 170:
 -#line 1790 "wcsbth.l"
-+#line 1787 "wcsbth.l"
++#line 1752 "wcsbth.l"
  case 171:
  YY_RULE_SETUP
 -#line 1790 "wcsbth.l"
-+#line 1787 "wcsbth.l"
++#line 1752 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.ssysobs;
-@@ -27876,10 +27873,10 @@ YY_RULE_SETUP
+@@ -27876,10 +27835,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 172:
 -#line 1804 "wcsbth.l"
-+#line 1801 "wcsbth.l"
++#line 1766 "wcsbth.l"
  case 173:
  YY_RULE_SETUP
 -#line 1804 "wcsbth.l"
-+#line 1801 "wcsbth.l"
++#line 1766 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.velosys);
-@@ -27895,7 +27892,7 @@ YY_RULE_SETUP
+@@ -27895,7 +27854,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 174:
  YY_RULE_SETUP
 -#line 1817 "wcsbth.l"
-+#line 1814 "wcsbth.l"
++#line 1779 "wcsbth.l"
  {
  	  if (relax & WCSHDR_VSOURCE) {
  	    valtype = FLOAT;
-@@ -27917,12 +27914,12 @@ YY_RULE_SETUP
+@@ -27917,12 +27876,12 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 175:
 -#line 1838 "wcsbth.l"
-+#line 1835 "wcsbth.l"
++#line 1800 "wcsbth.l"
  case 176:
 -#line 1839 "wcsbth.l"
-+#line 1836 "wcsbth.l"
++#line 1801 "wcsbth.l"
  case 177:
  YY_RULE_SETUP
 -#line 1839 "wcsbth.l"
-+#line 1836 "wcsbth.l"
++#line 1801 "wcsbth.l"
  {
  	  if (relax & WCSHDR_VSOURCE) {
  	    valtype = FLOAT;
-@@ -27938,16 +27935,16 @@ YY_RULE_SETUP
+@@ -27938,16 +27897,16 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -6048,119 +6966,124 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 178:
 -#line 1860 "wcsbth.l"
-+#line 1857 "wcsbth.l"
++#line 1822 "wcsbth.l"
  case 179:
  YY_RULE_SETUP
 -#line 1860 "wcsbth.l"
-+#line 1857 "wcsbth.l"
++#line 1822 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.zsource);
-@@ -27962,10 +27959,10 @@ YY_RULE_SETUP
+@@ -27962,10 +27921,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 180:
 -#line 1874 "wcsbth.l"
-+#line 1871 "wcsbth.l"
++#line 1836 "wcsbth.l"
  case 181:
  YY_RULE_SETUP
 -#line 1874 "wcsbth.l"
-+#line 1871 "wcsbth.l"
++#line 1836 "wcsbth.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.ssyssrc;
-@@ -27980,10 +27977,10 @@ YY_RULE_SETUP
+@@ -27980,10 +27939,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 182:
 -#line 1888 "wcsbth.l"
-+#line 1885 "wcsbth.l"
++#line 1850 "wcsbth.l"
  case 183:
  YY_RULE_SETUP
 -#line 1888 "wcsbth.l"
-+#line 1885 "wcsbth.l"
++#line 1850 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.velangl);
-@@ -27999,7 +27996,7 @@ YY_RULE_SETUP
+@@ -27999,7 +27958,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 184:
  YY_RULE_SETUP
 -#line 1901 "wcsbth.l"
-+#line 1898 "wcsbth.l"
++#line 1863 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  auxprm  = 1;
-@@ -28011,7 +28008,7 @@ YY_RULE_SETUP
+@@ -28011,7 +27970,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 185:
  YY_RULE_SETUP
 -#line 1910 "wcsbth.l"
-+#line 1907 "wcsbth.l"
++#line 1872 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  auxprm  = 1;
-@@ -28023,7 +28020,7 @@ YY_RULE_SETUP
+@@ -28023,7 +27982,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 186:
  YY_RULE_SETUP
 -#line 1919 "wcsbth.l"
-+#line 1916 "wcsbth.l"
++#line 1881 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  auxprm  = 1;
-@@ -28035,7 +28032,7 @@ YY_RULE_SETUP
+@@ -28035,7 +27994,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 187:
  YY_RULE_SETUP
 -#line 1928 "wcsbth.l"
-+#line 1925 "wcsbth.l"
++#line 1890 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  auxprm  = 1;
-@@ -28046,10 +28043,10 @@ YY_RULE_SETUP
+@@ -28046,10 +28005,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 188:
 -#line 1938 "wcsbth.l"
-+#line 1935 "wcsbth.l"
++#line 1900 "wcsbth.l"
  case 189:
  YY_RULE_SETUP
 -#line 1938 "wcsbth.l"
-+#line 1935 "wcsbth.l"
++#line 1900 "wcsbth.l"
  {
  	  valtype = FLOAT;
  	  auxprm  = 1;
-@@ -28061,7 +28058,7 @@ YY_RULE_SETUP
+@@ -28061,10 +28020,10 @@ YY_RULE_SETUP
  	YY_BREAK
  case 190:
  YY_RULE_SETUP
 -#line 1947 "wcsbth.l"
-+#line 1944 "wcsbth.l"
++#line 1909 "wcsbth.l"
  {
- 	  if (wcsbth_nkeyrec) {
- 	    wcsbth_nkeyrec = 0;
-@@ -28074,16 +28071,16 @@ YY_RULE_SETUP
+-	  if (wcsbth_nkeyrec) {
+-	    wcsbth_nkeyrec = 0;
++	  if (yyextra->nkeyrec) {
++	    yyextra->nkeyrec = 0;
+ 	    errmsg = "keyrecords following the END keyrecord were ignored";
+ 	    BEGIN(ERROR);
+ 	  } else {
+@@ -28074,16 +28033,16 @@ YY_RULE_SETUP
  	YY_BREAK
  case 191:
  YY_RULE_SETUP
 -#line 1957 "wcsbth.l"
-+#line 1954 "wcsbth.l"
++#line 1919 "wcsbth.l"
  {
  	  BEGIN(DISCARD);
  	}
  	YY_BREAK
  case 192:
 -#line 1962 "wcsbth.l"
-+#line 1959 "wcsbth.l"
++#line 1924 "wcsbth.l"
  case 193:
  YY_RULE_SETUP
 -#line 1962 "wcsbth.l"
-+#line 1959 "wcsbth.l"
++#line 1924 "wcsbth.l"
  {
  	  if (relax & WCSHDR_ALLIMG) {
  	    sscanf(yytext, "%d%c", &i, &a);
-@@ -28097,26 +28094,26 @@ YY_RULE_SETUP
+@@ -28097,26 +28056,26 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -6172,11 +7095,11 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 194:
 -#line 1981 "wcsbth.l"
-+#line 1978 "wcsbth.l"
++#line 1943 "wcsbth.l"
  case 195:
  YY_RULE_SETUP
 -#line 1981 "wcsbth.l"
-+#line 1978 "wcsbth.l"
++#line 1943 "wcsbth.l"
  {
  	  if (relax & WCSHDR_ALLIMG) {
  	    if (relax & WCSHDR_reject) {
@@ -6192,7 +7115,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	      BEGIN(DISCARD);
  	    }
  	
-@@ -28127,21 +28124,21 @@ YY_RULE_SETUP
+@@ -28127,21 +28086,21 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -6204,14 +7127,14 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 196:
 -#line 2007 "wcsbth.l"
-+#line 2004 "wcsbth.l"
++#line 1969 "wcsbth.l"
  case 197:
 -#line 2008 "wcsbth.l"
-+#line 2005 "wcsbth.l"
++#line 1970 "wcsbth.l"
  case 198:
  YY_RULE_SETUP
 -#line 2008 "wcsbth.l"
-+#line 2005 "wcsbth.l"
++#line 1970 "wcsbth.l"
  {
 -	  /* Anything that has fallen through to this point must contain */
 -	  /* an invalid axis number. */
@@ -6220,7 +7143,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	  if (relax & WCSHDR_ALLIMG) {
  	    errmsg = "axis number must exceed 0";
  	    BEGIN(ERROR);
-@@ -28153,41 +28150,41 @@ YY_RULE_SETUP
+@@ -28153,41 +28112,41 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -6233,7 +7156,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  case 199:
  YY_RULE_SETUP
 -#line 2027 "wcsbth.l"
-+#line 2024 "wcsbth.l"
++#line 1989 "wcsbth.l"
  {
  	  if (relax & WCSHDR_reject) {
 -	    /* Looks too much like a FITS WCS keyword not to flag it. */
@@ -6252,46 +7175,46 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 200:
 -#line 2042 "wcsbth.l"
-+#line 2039 "wcsbth.l"
++#line 2004 "wcsbth.l"
  case 201:
 -#line 2043 "wcsbth.l"
-+#line 2040 "wcsbth.l"
++#line 2005 "wcsbth.l"
  case 202:
 -#line 2044 "wcsbth.l"
-+#line 2041 "wcsbth.l"
++#line 2006 "wcsbth.l"
  case 203:
 -#line 2045 "wcsbth.l"
-+#line 2042 "wcsbth.l"
++#line 2007 "wcsbth.l"
  case 204:
 -#line 2046 "wcsbth.l"
-+#line 2043 "wcsbth.l"
++#line 2008 "wcsbth.l"
  case 205:
  YY_RULE_SETUP
 -#line 2046 "wcsbth.l"
-+#line 2043 "wcsbth.l"
++#line 2008 "wcsbth.l"
  {
  	  if (vptr) {
  	    WCSBTH_PUTBACK;
-@@ -28204,14 +28201,14 @@ YY_RULE_SETUP
+@@ -28204,14 +28163,14 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 206:
 -#line 2062 "wcsbth.l"
-+#line 2059 "wcsbth.l"
++#line 2024 "wcsbth.l"
  case 207:
 -#line 2063 "wcsbth.l"
-+#line 2060 "wcsbth.l"
++#line 2025 "wcsbth.l"
  case 208:
 -#line 2064 "wcsbth.l"
-+#line 2061 "wcsbth.l"
++#line 2026 "wcsbth.l"
  case 209:
  YY_RULE_SETUP
 -#line 2064 "wcsbth.l"
-+#line 2061 "wcsbth.l"
++#line 2026 "wcsbth.l"
  {
  	  if (vptr && (relax & WCSHDR_LONGKEY)) {
  	    WCSBTH_PUTBACK;
-@@ -28228,33 +28225,33 @@ YY_RULE_SETUP
+@@ -28228,33 +28187,33 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -6303,68 +7226,68 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 210:
 -#line 2086 "wcsbth.l"
-+#line 2083 "wcsbth.l"
++#line 2048 "wcsbth.l"
  case 211:
  YY_RULE_SETUP
 -#line 2086 "wcsbth.l"
-+#line 2083 "wcsbth.l"
++#line 2048 "wcsbth.l"
  {
  	  BEGIN(DISCARD);
  	}
  	YY_BREAK
  case 212:
 -#line 2091 "wcsbth.l"
-+#line 2088 "wcsbth.l"
++#line 2053 "wcsbth.l"
  case 213:
 -#line 2092 "wcsbth.l"
-+#line 2089 "wcsbth.l"
++#line 2054 "wcsbth.l"
  case 214:
 -#line 2093 "wcsbth.l"
-+#line 2090 "wcsbth.l"
++#line 2055 "wcsbth.l"
  case 215:
 -#line 2094 "wcsbth.l"
-+#line 2091 "wcsbth.l"
++#line 2056 "wcsbth.l"
  case 216:
 -#line 2095 "wcsbth.l"
-+#line 2092 "wcsbth.l"
++#line 2057 "wcsbth.l"
  case 217:
  YY_RULE_SETUP
 -#line 2095 "wcsbth.l"
-+#line 2092 "wcsbth.l"
++#line 2057 "wcsbth.l"
  {
  	  sscanf(yytext, "%d%c", &n, &a);
  	  if (YY_START == TCCCna) i = wcsbth_colax(*wcs, &alts, n, a);
-@@ -28263,23 +28260,23 @@ YY_RULE_SETUP
+@@ -28263,23 +28222,23 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 218:
 -#line 2103 "wcsbth.l"
-+#line 2100 "wcsbth.l"
++#line 2065 "wcsbth.l"
  case 219:
  YY_RULE_SETUP
 -#line 2103 "wcsbth.l"
-+#line 2100 "wcsbth.l"
++#line 2065 "wcsbth.l"
  {
  	  BEGIN(DISCARD);
  	}
  	YY_BREAK
  case 220:
 -#line 2108 "wcsbth.l"
-+#line 2105 "wcsbth.l"
++#line 2070 "wcsbth.l"
  case 221:
 -#line 2109 "wcsbth.l"
-+#line 2106 "wcsbth.l"
++#line 2071 "wcsbth.l"
  case 222:
 -#line 2110 "wcsbth.l"
-+#line 2107 "wcsbth.l"
++#line 2072 "wcsbth.l"
  case 223:
  YY_RULE_SETUP
 -#line 2110 "wcsbth.l"
-+#line 2107 "wcsbth.l"
++#line 2072 "wcsbth.l"
  {
  	  if (relax & WCSHDR_ALLIMG) {
  	    sscanf(yytext, "%d_%d%c", &i, &j, &a);
-@@ -28293,54 +28290,54 @@ YY_RULE_SETUP
+@@ -28293,54 +28252,54 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -6376,72 +7299,72 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 224:
 -#line 2129 "wcsbth.l"
-+#line 2126 "wcsbth.l"
++#line 2091 "wcsbth.l"
  case 225:
 -#line 2130 "wcsbth.l"
-+#line 2127 "wcsbth.l"
++#line 2092 "wcsbth.l"
  case 226:
 -#line 2131 "wcsbth.l"
-+#line 2128 "wcsbth.l"
++#line 2093 "wcsbth.l"
  case 227:
 -#line 2132 "wcsbth.l"
-+#line 2129 "wcsbth.l"
++#line 2094 "wcsbth.l"
  case 228:
 -#line 2133 "wcsbth.l"
-+#line 2130 "wcsbth.l"
++#line 2095 "wcsbth.l"
  case 229:
 -#line 2134 "wcsbth.l"
-+#line 2131 "wcsbth.l"
++#line 2096 "wcsbth.l"
  case 230:
 -#line 2135 "wcsbth.l"
-+#line 2132 "wcsbth.l"
++#line 2097 "wcsbth.l"
  case 231:
 -#line 2136 "wcsbth.l"
-+#line 2133 "wcsbth.l"
++#line 2098 "wcsbth.l"
  case 232:
 -#line 2137 "wcsbth.l"
-+#line 2134 "wcsbth.l"
++#line 2099 "wcsbth.l"
  case 233:
 -#line 2138 "wcsbth.l"
-+#line 2135 "wcsbth.l"
++#line 2100 "wcsbth.l"
  case 234:
 -#line 2139 "wcsbth.l"
-+#line 2136 "wcsbth.l"
++#line 2101 "wcsbth.l"
  case 235:
 -#line 2140 "wcsbth.l"
-+#line 2137 "wcsbth.l"
++#line 2102 "wcsbth.l"
  case 236:
 -#line 2141 "wcsbth.l"
-+#line 2138 "wcsbth.l"
++#line 2103 "wcsbth.l"
  case 237:
 -#line 2142 "wcsbth.l"
-+#line 2139 "wcsbth.l"
++#line 2104 "wcsbth.l"
  case 238:
 -#line 2143 "wcsbth.l"
-+#line 2140 "wcsbth.l"
++#line 2105 "wcsbth.l"
  case 239:
 -#line 2144 "wcsbth.l"
-+#line 2141 "wcsbth.l"
++#line 2106 "wcsbth.l"
  case 240:
 -#line 2145 "wcsbth.l"
-+#line 2142 "wcsbth.l"
++#line 2107 "wcsbth.l"
  case 241:
 -#line 2146 "wcsbth.l"
-+#line 2143 "wcsbth.l"
++#line 2108 "wcsbth.l"
  case 242:
 -#line 2147 "wcsbth.l"
-+#line 2144 "wcsbth.l"
++#line 2109 "wcsbth.l"
  case 243:
 -#line 2148 "wcsbth.l"
-+#line 2145 "wcsbth.l"
++#line 2110 "wcsbth.l"
  case 244:
  YY_RULE_SETUP
 -#line 2148 "wcsbth.l"
-+#line 2145 "wcsbth.l"
++#line 2110 "wcsbth.l"
  {
  	  if (relax & WCSHDR_ALLIMG) {
  	    if (((altlin == 1) && (relax & WCSHDR_PC0i_0ja)) ||
-@@ -28355,7 +28352,7 @@ YY_RULE_SETUP
+@@ -28355,7 +28314,7 @@ YY_RULE_SETUP
  	      BEGIN(ERROR);
  	
  	    } else {
@@ -6450,7 +7373,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	      BEGIN(DISCARD);
  	    }
  	
-@@ -28366,35 +28363,35 @@ YY_RULE_SETUP
+@@ -28366,35 +28325,35 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -6462,35 +7385,35 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 245:
 -#line 2179 "wcsbth.l"
-+#line 2176 "wcsbth.l"
++#line 2141 "wcsbth.l"
  case 246:
 -#line 2180 "wcsbth.l"
-+#line 2177 "wcsbth.l"
++#line 2142 "wcsbth.l"
  case 247:
 -#line 2181 "wcsbth.l"
-+#line 2178 "wcsbth.l"
++#line 2143 "wcsbth.l"
  case 248:
 -#line 2182 "wcsbth.l"
-+#line 2179 "wcsbth.l"
++#line 2144 "wcsbth.l"
  case 249:
 -#line 2183 "wcsbth.l"
-+#line 2180 "wcsbth.l"
++#line 2145 "wcsbth.l"
  case 250:
 -#line 2184 "wcsbth.l"
-+#line 2181 "wcsbth.l"
++#line 2146 "wcsbth.l"
  case 251:
 -#line 2185 "wcsbth.l"
-+#line 2182 "wcsbth.l"
++#line 2147 "wcsbth.l"
  case 252:
 -#line 2186 "wcsbth.l"
-+#line 2183 "wcsbth.l"
++#line 2148 "wcsbth.l"
  case 253:
 -#line 2187 "wcsbth.l"
-+#line 2184 "wcsbth.l"
++#line 2149 "wcsbth.l"
  case 254:
  YY_RULE_SETUP
 -#line 2187 "wcsbth.l"
-+#line 2184 "wcsbth.l"
++#line 2149 "wcsbth.l"
  {
 -	  /* Anything that has fallen through to this point must contain */
 -	  /* an invalid axis number. */
@@ -6499,7 +7422,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	  if (relax & WCSHDR_ALLIMG) {
  	    errmsg = "axis number must exceed 0";
  	    BEGIN(ERROR);
-@@ -28406,32 +28403,32 @@ YY_RULE_SETUP
+@@ -28406,32 +28365,32 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -6511,39 +7434,39 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 255:
 -#line 2207 "wcsbth.l"
-+#line 2204 "wcsbth.l"
++#line 2169 "wcsbth.l"
  case 256:
 -#line 2208 "wcsbth.l"
-+#line 2205 "wcsbth.l"
++#line 2170 "wcsbth.l"
  case 257:
 -#line 2209 "wcsbth.l"
-+#line 2206 "wcsbth.l"
++#line 2171 "wcsbth.l"
  case 258:
 -#line 2210 "wcsbth.l"
-+#line 2207 "wcsbth.l"
++#line 2172 "wcsbth.l"
  case 259:
 -#line 2211 "wcsbth.l"
-+#line 2208 "wcsbth.l"
++#line 2173 "wcsbth.l"
  case 260:
 -#line 2212 "wcsbth.l"
-+#line 2209 "wcsbth.l"
++#line 2174 "wcsbth.l"
  case 261:
 -#line 2213 "wcsbth.l"
-+#line 2210 "wcsbth.l"
++#line 2175 "wcsbth.l"
  case 262:
 -#line 2214 "wcsbth.l"
-+#line 2211 "wcsbth.l"
++#line 2176 "wcsbth.l"
  case 263:
 -#line 2215 "wcsbth.l"
-+#line 2212 "wcsbth.l"
++#line 2177 "wcsbth.l"
  case 264:
  YY_RULE_SETUP
 -#line 2215 "wcsbth.l"
-+#line 2212 "wcsbth.l"
++#line 2177 "wcsbth.l"
  {
  	  if (relax & WCSHDR_ALLIMG) {
  	    errmsg = errtxt;
-@@ -28446,16 +28443,16 @@ YY_RULE_SETUP
+@@ -28446,16 +28405,16 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -6556,14 +7479,14 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  case 265:
  YY_RULE_SETUP
 -#line 2234 "wcsbth.l"
-+#line 2231 "wcsbth.l"
++#line 2196 "wcsbth.l"
  {
 -	  /* This covers the defunct forms CD00i00j and PC00i00j. */
 +	  // This covers the defunct forms CD00i00j and PC00i00j.
  	  if (relax & WCSHDR_ALLIMG) {
  	    if (((altlin == 1) && (relax & WCSHDR_PC00i00j)) ||
  	        ((altlin == 2) && (relax & WCSHDR_CD00i00j))) {
-@@ -28472,7 +28469,7 @@ YY_RULE_SETUP
+@@ -28472,7 +28431,7 @@ YY_RULE_SETUP
  	      BEGIN(ERROR);
  	
  	    } else {
@@ -6572,7 +7495,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	      BEGIN(DISCARD);
  	    }
  	
-@@ -28483,25 +28480,25 @@ YY_RULE_SETUP
+@@ -28483,25 +28442,25 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -6585,50 +7508,50 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  case 266:
  YY_RULE_SETUP
 -#line 2268 "wcsbth.l"
-+#line 2265 "wcsbth.l"
++#line 2230 "wcsbth.l"
  {
  	  BEGIN(DISCARD);
  	}
  	YY_BREAK
  case 267:
 -#line 2273 "wcsbth.l"
-+#line 2270 "wcsbth.l"
++#line 2235 "wcsbth.l"
  case 268:
 -#line 2274 "wcsbth.l"
-+#line 2271 "wcsbth.l"
++#line 2236 "wcsbth.l"
  case 269:
  YY_RULE_SETUP
 -#line 2274 "wcsbth.l"
-+#line 2271 "wcsbth.l"
++#line 2236 "wcsbth.l"
  {
  	  sscanf(yytext, "%d%c", &n, &a);
  	  keytype = BIMGARR;
-@@ -28509,18 +28506,18 @@ YY_RULE_SETUP
+@@ -28509,18 +28468,18 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 270:
 -#line 2281 "wcsbth.l"
-+#line 2278 "wcsbth.l"
++#line 2243 "wcsbth.l"
  case 271:
 -#line 2282 "wcsbth.l"
-+#line 2279 "wcsbth.l"
++#line 2244 "wcsbth.l"
  case 272:
 -#line 2283 "wcsbth.l"
-+#line 2280 "wcsbth.l"
++#line 2245 "wcsbth.l"
  case 273:
 -#line 2284 "wcsbth.l"
-+#line 2281 "wcsbth.l"
++#line 2246 "wcsbth.l"
  case 274:
 -#line 2285 "wcsbth.l"
-+#line 2282 "wcsbth.l"
++#line 2247 "wcsbth.l"
  case 275:
  YY_RULE_SETUP
 -#line 2285 "wcsbth.l"
-+#line 2282 "wcsbth.l"
++#line 2247 "wcsbth.l"
  {
  	  if (relax & WCSHDR_LONGKEY) {
  	    WCSBTH_PUTBACK;
-@@ -28532,31 +28529,31 @@ YY_RULE_SETUP
+@@ -28532,31 +28491,31 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -6641,76 +7564,76 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  case 276:
  YY_RULE_SETUP
 -#line 2301 "wcsbth.l"
-+#line 2298 "wcsbth.l"
++#line 2263 "wcsbth.l"
  {
  	  BEGIN(DISCARD);
  	}
  	YY_BREAK
  case 277:
 -#line 2306 "wcsbth.l"
-+#line 2303 "wcsbth.l"
++#line 2268 "wcsbth.l"
  case 278:
 -#line 2307 "wcsbth.l"
-+#line 2304 "wcsbth.l"
++#line 2269 "wcsbth.l"
  case 279:
 -#line 2308 "wcsbth.l"
-+#line 2305 "wcsbth.l"
++#line 2270 "wcsbth.l"
  case 280:
 -#line 2309 "wcsbth.l"
-+#line 2306 "wcsbth.l"
++#line 2271 "wcsbth.l"
  case 281:
 -#line 2310 "wcsbth.l"
-+#line 2307 "wcsbth.l"
++#line 2272 "wcsbth.l"
  case 282:
  YY_RULE_SETUP
 -#line 2310 "wcsbth.l"
-+#line 2307 "wcsbth.l"
++#line 2272 "wcsbth.l"
  {
  	  sscanf(yytext, "%d_%d%c", &n, &k, &a);
  	  i = wcsbth_colax(*wcs, &alts, n, a);
-@@ -28566,14 +28563,14 @@ YY_RULE_SETUP
+@@ -28566,14 +28525,14 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 283:
 -#line 2319 "wcsbth.l"
-+#line 2316 "wcsbth.l"
++#line 2281 "wcsbth.l"
  case 284:
 -#line 2320 "wcsbth.l"
-+#line 2317 "wcsbth.l"
++#line 2282 "wcsbth.l"
  case 285:
 -#line 2321 "wcsbth.l"
-+#line 2318 "wcsbth.l"
++#line 2283 "wcsbth.l"
  case 286:
  YY_RULE_SETUP
 -#line 2321 "wcsbth.l"
-+#line 2318 "wcsbth.l"
++#line 2283 "wcsbth.l"
  {
  	  sscanf(yytext, "%d_%d", &n, &k);
  	  a = ' ';
-@@ -28585,18 +28582,18 @@ YY_RULE_SETUP
+@@ -28585,18 +28544,18 @@ YY_RULE_SETUP
  	YY_BREAK
  case 287:
  YY_RULE_SETUP
 -#line 2330 "wcsbth.l"
-+#line 2327 "wcsbth.l"
++#line 2292 "wcsbth.l"
  {
  	  BEGIN(DISCARD);
  	}
  	YY_BREAK
  case 288:
 -#line 2335 "wcsbth.l"
-+#line 2332 "wcsbth.l"
++#line 2297 "wcsbth.l"
  case 289:
 -#line 2336 "wcsbth.l"
-+#line 2333 "wcsbth.l"
++#line 2298 "wcsbth.l"
  case 290:
  YY_RULE_SETUP
 -#line 2336 "wcsbth.l"
-+#line 2333 "wcsbth.l"
++#line 2298 "wcsbth.l"
  {
  	  if (relax & WCSHDR_ALLIMG) {
  	    a = ' ';
-@@ -28615,7 +28612,7 @@ YY_RULE_SETUP
+@@ -28615,7 +28574,7 @@ YY_RULE_SETUP
  	      BEGIN(ERROR);
  	
  	    } else {
@@ -6719,7 +7642,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	      BEGIN(DISCARD);
  	    }
  	
-@@ -28626,51 +28623,51 @@ YY_RULE_SETUP
+@@ -28626,51 +28585,51 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -6732,7 +7655,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  case 291:
  YY_RULE_SETUP
 -#line 2370 "wcsbth.l"
-+#line 2367 "wcsbth.l"
++#line 2332 "wcsbth.l"
  {
  	  if (relax & WCSHDR_ALLIMG) {
  	    yyless(0);
@@ -6746,23 +7669,23 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 292:
 -#line 2381 "wcsbth.l"
-+#line 2378 "wcsbth.l"
++#line 2343 "wcsbth.l"
  case 293:
 -#line 2382 "wcsbth.l"
-+#line 2379 "wcsbth.l"
++#line 2344 "wcsbth.l"
  case 294:
 -#line 2383 "wcsbth.l"
-+#line 2380 "wcsbth.l"
++#line 2345 "wcsbth.l"
  case 295:
 -#line 2384 "wcsbth.l"
-+#line 2381 "wcsbth.l"
++#line 2346 "wcsbth.l"
  case 296:
 -#line 2385 "wcsbth.l"
-+#line 2382 "wcsbth.l"
++#line 2347 "wcsbth.l"
  case 297:
  YY_RULE_SETUP
 -#line 2385 "wcsbth.l"
-+#line 2382 "wcsbth.l"
++#line 2347 "wcsbth.l"
  {
  	  WCSBTH_PUTBACK;
  	  BEGIN((YY_START == iCROTn) ? iCCCna : TCCCna);
@@ -6770,21 +7693,21 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 298:
 -#line 2391 "wcsbth.l"
-+#line 2388 "wcsbth.l"
++#line 2353 "wcsbth.l"
  case 299:
 -#line 2392 "wcsbth.l"
-+#line 2389 "wcsbth.l"
++#line 2354 "wcsbth.l"
  case 300:
 -#line 2393 "wcsbth.l"
-+#line 2390 "wcsbth.l"
++#line 2355 "wcsbth.l"
  case 301:
  YY_RULE_SETUP
 -#line 2393 "wcsbth.l"
-+#line 2390 "wcsbth.l"
++#line 2355 "wcsbth.l"
  {
  	  if (relax & WCSHDR_CROTAia) {
  	    WCSBTH_PUTBACK;
-@@ -28683,27 +28680,27 @@ YY_RULE_SETUP
+@@ -28683,27 +28642,27 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -6796,29 +7719,29 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 302:
 -#line 2411 "wcsbth.l"
-+#line 2408 "wcsbth.l"
++#line 2373 "wcsbth.l"
  case 303:
  YY_RULE_SETUP
 -#line 2411 "wcsbth.l"
-+#line 2408 "wcsbth.l"
++#line 2373 "wcsbth.l"
  {
  	  BEGIN(DISCARD);
  	}
  	YY_BREAK
  case 304:
 -#line 2416 "wcsbth.l"
-+#line 2413 "wcsbth.l"
++#line 2378 "wcsbth.l"
  case 305:
  YY_RULE_SETUP
 -#line 2416 "wcsbth.l"
-+#line 2413 "wcsbth.l"
++#line 2378 "wcsbth.l"
  {
 -	  /* Image-header keyword. */
 +	  // Image-header keyword.
  	  if (imherit || (relax & (WCSHDR_AUXIMG | WCSHDR_ALLIMG))) {
  	    if (YY_START == CCCCCCCa) {
  	      sscanf(yytext, "%c", &a);
-@@ -28721,39 +28718,39 @@ YY_RULE_SETUP
+@@ -28721,39 +28680,39 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -6831,7 +7754,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  case 306:
  YY_RULE_SETUP
 -#line 2440 "wcsbth.l"
-+#line 2437 "wcsbth.l"
++#line 2402 "wcsbth.l"
  {
  	  if (relax & WCSHDR_reject) {
 -	    /* Looks too much like a FITS WCS keyword not to flag it. */
@@ -6850,105 +7773,105 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 307:
 -#line 2455 "wcsbth.l"
-+#line 2452 "wcsbth.l"
++#line 2417 "wcsbth.l"
  case 308:
 -#line 2456 "wcsbth.l"
-+#line 2453 "wcsbth.l"
++#line 2418 "wcsbth.l"
  case 309:
 -#line 2457 "wcsbth.l"
-+#line 2454 "wcsbth.l"
++#line 2419 "wcsbth.l"
  case 310:
 -#line 2458 "wcsbth.l"
-+#line 2455 "wcsbth.l"
++#line 2420 "wcsbth.l"
  case 311:
  YY_RULE_SETUP
 -#line 2458 "wcsbth.l"
-+#line 2455 "wcsbth.l"
++#line 2420 "wcsbth.l"
  {
  	  sscanf(yytext, "%d%c", &n, &a);
  	  keytype = BINTAB;
-@@ -28762,7 +28759,7 @@ YY_RULE_SETUP
+@@ -28762,7 +28721,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 312:
  YY_RULE_SETUP
 -#line 2464 "wcsbth.l"
-+#line 2461 "wcsbth.l"
++#line 2426 "wcsbth.l"
  {
  	  sscanf(yytext, "%d", &n);
  	  a = ' ';
-@@ -28771,29 +28768,29 @@ YY_RULE_SETUP
+@@ -28771,29 +28730,29 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 313:
 -#line 2472 "wcsbth.l"
-+#line 2469 "wcsbth.l"
++#line 2434 "wcsbth.l"
  case 314:
  YY_RULE_SETUP
 -#line 2472 "wcsbth.l"
-+#line 2469 "wcsbth.l"
++#line 2434 "wcsbth.l"
  {
  	  BEGIN(DISCARD);
  	}
  	YY_BREAK
  case 315:
 -#line 2477 "wcsbth.l"
-+#line 2474 "wcsbth.l"
++#line 2439 "wcsbth.l"
  case 316:
 -#line 2478 "wcsbth.l"
-+#line 2475 "wcsbth.l"
++#line 2440 "wcsbth.l"
  case 317:
 -#line 2479 "wcsbth.l"
-+#line 2476 "wcsbth.l"
++#line 2441 "wcsbth.l"
  case 318:
 -#line 2480 "wcsbth.l"
-+#line 2477 "wcsbth.l"
++#line 2442 "wcsbth.l"
  case 319:
 -#line 2481 "wcsbth.l"
-+#line 2478 "wcsbth.l"
++#line 2443 "wcsbth.l"
  case 320:
 -#line 2482 "wcsbth.l"
-+#line 2479 "wcsbth.l"
++#line 2444 "wcsbth.l"
  case 321:
  YY_RULE_SETUP
 -#line 2482 "wcsbth.l"
-+#line 2479 "wcsbth.l"
++#line 2444 "wcsbth.l"
  {
  	  sscanf(yytext, "%d", &n);
  	  a = 0;
-@@ -28802,25 +28799,25 @@ YY_RULE_SETUP
+@@ -28802,25 +28761,25 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 322:
 -#line 2490 "wcsbth.l"
-+#line 2487 "wcsbth.l"
++#line 2452 "wcsbth.l"
  case 323:
  YY_RULE_SETUP
 -#line 2490 "wcsbth.l"
-+#line 2487 "wcsbth.l"
++#line 2452 "wcsbth.l"
  {
  	  BEGIN(DISCARD);
  	}
  	YY_BREAK
  case 324:
 -#line 2495 "wcsbth.l"
-+#line 2492 "wcsbth.l"
++#line 2457 "wcsbth.l"
  case 325:
 -#line 2496 "wcsbth.l"
-+#line 2493 "wcsbth.l"
++#line 2458 "wcsbth.l"
  case 326:
 -#line 2497 "wcsbth.l"
-+#line 2494 "wcsbth.l"
++#line 2459 "wcsbth.l"
  case 327:
  YY_RULE_SETUP
 -#line 2497 "wcsbth.l"
-+#line 2494 "wcsbth.l"
++#line 2459 "wcsbth.l"
  {
 -	  /* Image-header keyword. */
 +	  // Image-header keyword.
  	  if (relax & WCSHDR_ALLIMG) {
  	    sscanf(yytext, "%d_%d%c", &i, &m, &a);
  	    keytype = IMGAXIS;
-@@ -28833,54 +28830,54 @@ YY_RULE_SETUP
+@@ -28833,54 +28792,54 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -6960,72 +7883,72 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 328:
 -#line 2517 "wcsbth.l"
-+#line 2514 "wcsbth.l"
++#line 2479 "wcsbth.l"
  case 329:
 -#line 2518 "wcsbth.l"
-+#line 2515 "wcsbth.l"
++#line 2480 "wcsbth.l"
  case 330:
 -#line 2519 "wcsbth.l"
-+#line 2516 "wcsbth.l"
++#line 2481 "wcsbth.l"
  case 331:
 -#line 2520 "wcsbth.l"
-+#line 2517 "wcsbth.l"
++#line 2482 "wcsbth.l"
  case 332:
 -#line 2521 "wcsbth.l"
-+#line 2518 "wcsbth.l"
++#line 2483 "wcsbth.l"
  case 333:
 -#line 2522 "wcsbth.l"
-+#line 2519 "wcsbth.l"
++#line 2484 "wcsbth.l"
  case 334:
 -#line 2523 "wcsbth.l"
-+#line 2520 "wcsbth.l"
++#line 2485 "wcsbth.l"
  case 335:
 -#line 2524 "wcsbth.l"
-+#line 2521 "wcsbth.l"
++#line 2486 "wcsbth.l"
  case 336:
 -#line 2525 "wcsbth.l"
-+#line 2522 "wcsbth.l"
++#line 2487 "wcsbth.l"
  case 337:
 -#line 2526 "wcsbth.l"
-+#line 2523 "wcsbth.l"
++#line 2488 "wcsbth.l"
  case 338:
 -#line 2527 "wcsbth.l"
-+#line 2524 "wcsbth.l"
++#line 2489 "wcsbth.l"
  case 339:
 -#line 2528 "wcsbth.l"
-+#line 2525 "wcsbth.l"
++#line 2490 "wcsbth.l"
  case 340:
 -#line 2529 "wcsbth.l"
-+#line 2526 "wcsbth.l"
++#line 2491 "wcsbth.l"
  case 341:
 -#line 2530 "wcsbth.l"
-+#line 2527 "wcsbth.l"
++#line 2492 "wcsbth.l"
  case 342:
 -#line 2531 "wcsbth.l"
-+#line 2528 "wcsbth.l"
++#line 2493 "wcsbth.l"
  case 343:
 -#line 2532 "wcsbth.l"
-+#line 2529 "wcsbth.l"
++#line 2494 "wcsbth.l"
  case 344:
 -#line 2533 "wcsbth.l"
-+#line 2530 "wcsbth.l"
++#line 2495 "wcsbth.l"
  case 345:
 -#line 2534 "wcsbth.l"
-+#line 2531 "wcsbth.l"
++#line 2496 "wcsbth.l"
  case 346:
 -#line 2535 "wcsbth.l"
-+#line 2532 "wcsbth.l"
++#line 2497 "wcsbth.l"
  case 347:
 -#line 2536 "wcsbth.l"
-+#line 2533 "wcsbth.l"
++#line 2498 "wcsbth.l"
  case 348:
  YY_RULE_SETUP
 -#line 2536 "wcsbth.l"
-+#line 2533 "wcsbth.l"
++#line 2498 "wcsbth.l"
  {
  	  if (relax & WCSHDR_ALLIMG) {
  	    if (((valtype == FLOAT)  && (relax & WCSHDR_PV0i_0ma)) ||
-@@ -28895,7 +28892,7 @@ YY_RULE_SETUP
+@@ -28895,7 +28854,7 @@ YY_RULE_SETUP
  	      BEGIN(ERROR);
  	
  	    } else {
@@ -7034,7 +7957,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	      BEGIN(DISCARD);
  	    }
  	
-@@ -28906,36 +28903,36 @@ YY_RULE_SETUP
+@@ -28906,36 +28865,36 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -7046,35 +7969,35 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 349:
 -#line 2567 "wcsbth.l"
-+#line 2564 "wcsbth.l"
++#line 2529 "wcsbth.l"
  case 350:
 -#line 2568 "wcsbth.l"
-+#line 2565 "wcsbth.l"
++#line 2530 "wcsbth.l"
  case 351:
 -#line 2569 "wcsbth.l"
-+#line 2566 "wcsbth.l"
++#line 2531 "wcsbth.l"
  case 352:
 -#line 2570 "wcsbth.l"
-+#line 2567 "wcsbth.l"
++#line 2532 "wcsbth.l"
  case 353:
 -#line 2571 "wcsbth.l"
-+#line 2568 "wcsbth.l"
++#line 2533 "wcsbth.l"
  case 354:
 -#line 2572 "wcsbth.l"
-+#line 2569 "wcsbth.l"
++#line 2534 "wcsbth.l"
  case 355:
 -#line 2573 "wcsbth.l"
-+#line 2570 "wcsbth.l"
++#line 2535 "wcsbth.l"
  case 356:
 -#line 2574 "wcsbth.l"
-+#line 2571 "wcsbth.l"
++#line 2536 "wcsbth.l"
  case 357:
 -#line 2575 "wcsbth.l"
-+#line 2572 "wcsbth.l"
++#line 2537 "wcsbth.l"
  case 358:
  YY_RULE_SETUP
 -#line 2575 "wcsbth.l"
-+#line 2572 "wcsbth.l"
++#line 2537 "wcsbth.l"
  {
  	  if (relax & WCSHDR_ALLIMG) {
 -	    /* Anything that has fallen through to this point must contain */
@@ -7084,7 +8007,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	    errmsg = "axis number must exceed 0";
  	    BEGIN(ERROR);
  	
-@@ -28946,32 +28943,32 @@ YY_RULE_SETUP
+@@ -28946,32 +28905,32 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -7096,89 +8019,89 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 359:
 -#line 2595 "wcsbth.l"
-+#line 2592 "wcsbth.l"
++#line 2557 "wcsbth.l"
  case 360:
 -#line 2596 "wcsbth.l"
-+#line 2593 "wcsbth.l"
++#line 2558 "wcsbth.l"
  case 361:
 -#line 2597 "wcsbth.l"
-+#line 2594 "wcsbth.l"
++#line 2559 "wcsbth.l"
  case 362:
 -#line 2598 "wcsbth.l"
-+#line 2595 "wcsbth.l"
++#line 2560 "wcsbth.l"
  case 363:
 -#line 2599 "wcsbth.l"
-+#line 2596 "wcsbth.l"
++#line 2561 "wcsbth.l"
  case 364:
 -#line 2600 "wcsbth.l"
-+#line 2597 "wcsbth.l"
++#line 2562 "wcsbth.l"
  case 365:
 -#line 2601 "wcsbth.l"
-+#line 2598 "wcsbth.l"
++#line 2563 "wcsbth.l"
  case 366:
 -#line 2602 "wcsbth.l"
-+#line 2599 "wcsbth.l"
++#line 2564 "wcsbth.l"
  case 367:
 -#line 2603 "wcsbth.l"
-+#line 2600 "wcsbth.l"
++#line 2565 "wcsbth.l"
  case 368:
  YY_RULE_SETUP
 -#line 2603 "wcsbth.l"
-+#line 2600 "wcsbth.l"
++#line 2565 "wcsbth.l"
  {
  	  errmsg = errtxt;
  	  sprintf(errmsg, "%s keyword must use an underscore, not a dash",
-@@ -28981,36 +28978,36 @@ YY_RULE_SETUP
+@@ -28981,36 +28940,36 @@ YY_RULE_SETUP
  	YY_BREAK
  case 369:
  YY_RULE_SETUP
 -#line 2610 "wcsbth.l"
-+#line 2607 "wcsbth.l"
++#line 2572 "wcsbth.l"
  {
  	  BEGIN(DISCARD);
  	}
  	YY_BREAK
  case 370:
 -#line 2615 "wcsbth.l"
-+#line 2612 "wcsbth.l"
++#line 2577 "wcsbth.l"
  case 371:
 -#line 2616 "wcsbth.l"
-+#line 2613 "wcsbth.l"
++#line 2578 "wcsbth.l"
  case 372:
 -#line 2617 "wcsbth.l"
-+#line 2614 "wcsbth.l"
++#line 2579 "wcsbth.l"
  case 373:
 -#line 2618 "wcsbth.l"
-+#line 2615 "wcsbth.l"
++#line 2580 "wcsbth.l"
  case 374:
 -#line 2619 "wcsbth.l"
-+#line 2616 "wcsbth.l"
++#line 2581 "wcsbth.l"
  case 375:
 -#line 2620 "wcsbth.l"
-+#line 2617 "wcsbth.l"
++#line 2582 "wcsbth.l"
  case 376:
 -#line 2621 "wcsbth.l"
-+#line 2618 "wcsbth.l"
++#line 2583 "wcsbth.l"
  case 377:
 -#line 2622 "wcsbth.l"
-+#line 2619 "wcsbth.l"
++#line 2584 "wcsbth.l"
  case 378:
 -#line 2623 "wcsbth.l"
-+#line 2620 "wcsbth.l"
++#line 2585 "wcsbth.l"
  case 379:
 -#line 2624 "wcsbth.l"
-+#line 2621 "wcsbth.l"
++#line 2586 "wcsbth.l"
  case 380:
 -#line 2625 "wcsbth.l"
-+#line 2622 "wcsbth.l"
++#line 2587 "wcsbth.l"
  case 381:
  YY_RULE_SETUP
 -#line 2625 "wcsbth.l"
-+#line 2622 "wcsbth.l"
++#line 2587 "wcsbth.l"
  {
  	  if (relax & WCSHDR_LONGKEY) {
  	    WCSBTH_PUTBACK;
-@@ -29022,45 +29019,45 @@ YY_RULE_SETUP
+@@ -29022,45 +28981,45 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -7190,99 +8113,99 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 382:
 -#line 2642 "wcsbth.l"
-+#line 2639 "wcsbth.l"
++#line 2604 "wcsbth.l"
  case 383:
  YY_RULE_SETUP
 -#line 2642 "wcsbth.l"
-+#line 2639 "wcsbth.l"
++#line 2604 "wcsbth.l"
  {
  	  BEGIN(DISCARD);
  	}
  	YY_BREAK
  case 384:
 -#line 2647 "wcsbth.l"
-+#line 2644 "wcsbth.l"
++#line 2609 "wcsbth.l"
  case 385:
 -#line 2648 "wcsbth.l"
-+#line 2645 "wcsbth.l"
++#line 2610 "wcsbth.l"
  case 386:
 -#line 2649 "wcsbth.l"
-+#line 2646 "wcsbth.l"
++#line 2611 "wcsbth.l"
  case 387:
 -#line 2650 "wcsbth.l"
-+#line 2647 "wcsbth.l"
++#line 2612 "wcsbth.l"
  case 388:
 -#line 2651 "wcsbth.l"
-+#line 2648 "wcsbth.l"
++#line 2613 "wcsbth.l"
  case 389:
 -#line 2652 "wcsbth.l"
-+#line 2649 "wcsbth.l"
++#line 2614 "wcsbth.l"
  case 390:
 -#line 2653 "wcsbth.l"
-+#line 2650 "wcsbth.l"
++#line 2615 "wcsbth.l"
  case 391:
 -#line 2654 "wcsbth.l"
-+#line 2651 "wcsbth.l"
++#line 2616 "wcsbth.l"
  case 392:
 -#line 2655 "wcsbth.l"
-+#line 2652 "wcsbth.l"
++#line 2617 "wcsbth.l"
  case 393:
 -#line 2656 "wcsbth.l"
-+#line 2653 "wcsbth.l"
++#line 2618 "wcsbth.l"
  case 394:
 -#line 2657 "wcsbth.l"
-+#line 2654 "wcsbth.l"
++#line 2619 "wcsbth.l"
  case 395:
  YY_RULE_SETUP
 -#line 2657 "wcsbth.l"
-+#line 2654 "wcsbth.l"
++#line 2619 "wcsbth.l"
  {
  	  sscanf(yytext, "%d_%d%c", &n, &m, &a);
  	  if (YY_START == TCn_ma) i = wcsbth_colax(*wcs, &alts, n, a);
-@@ -29069,24 +29066,24 @@ YY_RULE_SETUP
+@@ -29069,24 +29028,24 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 396:
 -#line 2665 "wcsbth.l"
-+#line 2662 "wcsbth.l"
++#line 2627 "wcsbth.l"
  case 397:
 -#line 2666 "wcsbth.l"
-+#line 2663 "wcsbth.l"
++#line 2628 "wcsbth.l"
  case 398:
 -#line 2667 "wcsbth.l"
-+#line 2664 "wcsbth.l"
++#line 2629 "wcsbth.l"
  case 399:
 -#line 2668 "wcsbth.l"
-+#line 2665 "wcsbth.l"
++#line 2630 "wcsbth.l"
  case 400:
 -#line 2669 "wcsbth.l"
-+#line 2666 "wcsbth.l"
++#line 2631 "wcsbth.l"
  case 401:
 -#line 2670 "wcsbth.l"
-+#line 2667 "wcsbth.l"
++#line 2632 "wcsbth.l"
  case 402:
 -#line 2671 "wcsbth.l"
-+#line 2668 "wcsbth.l"
++#line 2633 "wcsbth.l"
  case 403:
  YY_RULE_SETUP
 -#line 2671 "wcsbth.l"
-+#line 2668 "wcsbth.l"
++#line 2633 "wcsbth.l"
  {
 -	  /* Invalid combinations will be flagged by <VALUE>. */
 +	  // Invalid combinations will be flagged by <VALUE>.
  	  sscanf(yytext, "%d_%d", &n, &m);
  	  a = ' ';
  	  if (YY_START == TCn_ma) i = wcsbth_colax(*wcs, &alts, n, a);
-@@ -29095,17 +29092,17 @@ YY_RULE_SETUP
+@@ -29095,17 +29054,17 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 404:
 -#line 2681 "wcsbth.l"
-+#line 2678 "wcsbth.l"
++#line 2643 "wcsbth.l"
  case 405:
  YY_RULE_SETUP
 -#line 2681 "wcsbth.l"
-+#line 2678 "wcsbth.l"
++#line 2643 "wcsbth.l"
  {
  	  BEGIN(DISCARD);
  	}
@@ -7290,11 +8213,11 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  case 406:
  YY_RULE_SETUP
 -#line 2685 "wcsbth.l"
-+#line 2682 "wcsbth.l"
++#line 2647 "wcsbth.l"
  {
  	  if (relax & WCSHDR_PROJPn) {
  	    sscanf(yytext, "%d", &m);
-@@ -29119,16 +29116,16 @@ YY_RULE_SETUP
+@@ -29119,16 +29078,16 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -7306,20 +8229,20 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	YY_BREAK
  case 407:
 -#line 2704 "wcsbth.l"
-+#line 2701 "wcsbth.l"
++#line 2666 "wcsbth.l"
  case 408:
  YY_RULE_SETUP
 -#line 2704 "wcsbth.l"
-+#line 2701 "wcsbth.l"
++#line 2666 "wcsbth.l"
  {
  	  if (relax & (WCSHDR_PROJPn | WCSHDR_reject)) {
  	    errmsg = "invalid PROJPn keyword";
-@@ -29141,25 +29138,25 @@ YY_RULE_SETUP
+@@ -29141,26 +29100,26 @@ YY_RULE_SETUP
  	YY_BREAK
  case 409:
  YY_RULE_SETUP
 -#line 2714 "wcsbth.l"
-+#line 2711 "wcsbth.l"
++#line 2676 "wcsbth.l"
  {
  	  BEGIN(DISCARD);
  	}
@@ -7327,7 +8250,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  case 410:
  YY_RULE_SETUP
 -#line 2718 "wcsbth.l"
-+#line 2715 "wcsbth.l"
++#line 2680 "wcsbth.l"
  {
 -	  /* Do checks on i, j, m, n, k. */
 +	  // Do checks on i, j, m, n, k.
@@ -7342,12 +8265,14 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	    if (k && (exclude[n] != exclude[k])) {
 -	      /* For keywords such as TCn_ka, both columns must be excluded.
 -	         User error, so return immediately. */
+-	      return 3;
 +	      // For keywords such as TCn_ka, both columns must be excluded.
 +	      // User error, so return immediately.
- 	      return 3;
++	      return WCSHDRERR_BAD_COLUMN;
  	
  	    } else {
-@@ -29179,18 +29176,18 @@ YY_RULE_SETUP
+ 	      BEGIN(DISCARD);
+@@ -29179,18 +29138,18 @@ YY_RULE_SETUP
  	      BEGIN(ERROR);
  	
  	    } else {
@@ -7370,21 +8295,21 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	      vptr = 0x0;
  	    }
  	
-@@ -29213,7 +29210,7 @@ YY_RULE_SETUP
+@@ -29213,7 +29172,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 411:
  YY_RULE_SETUP
 -#line 2780 "wcsbth.l"
-+#line 2777 "wcsbth.l"
++#line 2742 "wcsbth.l"
  {
  	  errmsg = "invalid KEYWORD = VALUE syntax";
  	  BEGIN(ERROR);
-@@ -29221,13 +29218,13 @@ YY_RULE_SETUP
+@@ -29221,13 +29180,13 @@ YY_RULE_SETUP
  	YY_BREAK
  case 412:
  YY_RULE_SETUP
 -#line 2785 "wcsbth.l"
-+#line 2782 "wcsbth.l"
++#line 2747 "wcsbth.l"
  {
  	  if (ipass == 1) {
  	    BEGIN(COMMENT);
@@ -7395,21 +8320,21 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	    sscanf(yytext, "%d", &inttmp);
  	
  	    BEGIN(COMMENT);
-@@ -29236,7 +29233,7 @@ YY_RULE_SETUP
+@@ -29236,7 +29195,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 413:
  YY_RULE_SETUP
 -#line 2797 "wcsbth.l"
-+#line 2794 "wcsbth.l"
++#line 2759 "wcsbth.l"
  {
  	  errmsg = "an integer value was expected";
  	  BEGIN(ERROR);
-@@ -29244,13 +29241,13 @@ YY_RULE_SETUP
+@@ -29244,13 +29203,13 @@ YY_RULE_SETUP
  	YY_BREAK
  case 414:
  YY_RULE_SETUP
 -#line 2802 "wcsbth.l"
-+#line 2799 "wcsbth.l"
++#line 2764 "wcsbth.l"
  {
  	  if (ipass == 1) {
  	    BEGIN(COMMENT);
@@ -7420,21 +8345,21 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	    wcsutil_str2double(yytext, &dbltmp);
  	
  	    if (chekval && chekval(dbltmp)) {
-@@ -29264,7 +29261,7 @@ YY_RULE_SETUP
+@@ -29264,7 +29223,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 415:
  YY_RULE_SETUP
 -#line 2819 "wcsbth.l"
-+#line 2816 "wcsbth.l"
++#line 2781 "wcsbth.l"
  {
  	  errmsg = "a floating-point value was expected";
  	  BEGIN(ERROR);
-@@ -29272,13 +29269,13 @@ YY_RULE_SETUP
+@@ -29272,13 +29231,13 @@ YY_RULE_SETUP
  	YY_BREAK
  case 416:
  YY_RULE_SETUP
 -#line 2824 "wcsbth.l"
-+#line 2821 "wcsbth.l"
++#line 2786 "wcsbth.l"
  {
  	  if (ipass == 1) {
  	    BEGIN(COMMENT);
@@ -7445,50 +8370,55 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	    wcsutil_str2double2(yytext, dbl2tmp);
  	
  	    BEGIN(COMMENT);
-@@ -29287,7 +29284,7 @@ YY_RULE_SETUP
+@@ -29287,7 +29246,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 417:
  YY_RULE_SETUP
 -#line 2836 "wcsbth.l"
-+#line 2833 "wcsbth.l"
++#line 2798 "wcsbth.l"
  {
  	  errmsg = "a floating-point value was expected";
  	  BEGIN(ERROR);
-@@ -29296,16 +29293,16 @@ YY_RULE_SETUP
+@@ -29296,18 +29255,18 @@ YY_RULE_SETUP
  case 418:
  /* rule 418 can match eol */
  YY_RULE_SETUP
 -#line 2841 "wcsbth.l"
-+#line 2838 "wcsbth.l"
++#line 2803 "wcsbth.l"
  {
  	  if (ipass == 1) {
  	    BEGIN(COMMENT);
  	
  	  } else {
 -	    /* Read the keyvalue. */
+-	      strcpy(strtmp, yytext+1);
 +	    // Read the keyvalue.
- 	      strcpy(strtmp, yytext+1);
++	    strcpy(strtmp, yytext+1);
  	
 -	    /* Squeeze out repeated quotes. */
+-	    ix = 0;
+-	    for (jx = 0; jx < 72; jx++) {
 +	    // Squeeze out repeated quotes.
- 	    ix = 0;
- 	    for (jx = 0; jx < 72; jx++) {
++	    int ix = 0;
++	    for (int jx = 0; jx < 72; jx++) {
  	      if (ix < jx) {
-@@ -29328,7 +29325,7 @@ YY_RULE_SETUP
+ 	        strtmp[ix] = strtmp[jx];
+ 	      }
+@@ -29328,7 +29287,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 419:
  YY_RULE_SETUP
 -#line 2870 "wcsbth.l"
-+#line 2867 "wcsbth.l"
++#line 2832 "wcsbth.l"
  {
  	  errmsg = "a string value was expected";
  	  BEGIN(ERROR);
-@@ -29339,31 +29336,31 @@ case 420:
+@@ -29339,32 +29298,34 @@ case 420:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 2875 "wcsbth.l"
-+#line 2872 "wcsbth.l"
++#line 2837 "wcsbth.l"
  {
  	  if (ipass == 1) {
 -	    /* Do first-pass bookkeeping. */
@@ -7503,34 +8433,43 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	    alts.ialt = 0;
  	
 -	    /* Update each coordinate representation. */
+-	    gotone = 0;
 +	    // Update each coordinate representation.
- 	    gotone = 0;
++	    int gotone = 0;
++	    struct wcsprm *wcsp;
  	    while ((wcsp = wcsbth_idx(*wcs, &alts, keytype, n, a))) {
  	      gotone = 1;
  	
  	      if (vptr) {
++	        void *wptr;
  	        if (auxprm) {
 -	          /* Additional auxiliary parameter. */
 +	          // Additional auxiliary parameter.
  	          auxp = wcsp->aux;
- 	          voff = (char *)vptr - (char *)(&auxtem);
+-	          voff = (char *)vptr - (char *)(&auxtem);
++	          ptrdiff_t voff = (char *)vptr - (char *)(&auxtem);
  	          wptr = (void *)((char *)auxp + voff);
  	        } else {
 -	          /* A parameter that lives directly in wcsprm. */
+-	          voff = (char *)vptr - (char *)(&wcstem);
 +	          // A parameter that lives directly in wcsprm.
- 	          voff = (char *)vptr - (char *)(&wcstem);
++	          ptrdiff_t voff = (char *)vptr - (char *)(&wcstem);
  	          wptr = (void *)((char *)wcsp + voff);
  	        }
-@@ -29372,7 +29369,7 @@ YY_RULE_SETUP
+ 	
+@@ -29372,9 +29333,9 @@ YY_RULE_SETUP
  	          *((int *)wptr) = inttmp;
  	
  	        } else if (valtype == FLOAT) {
 -	          /* Apply keyword parameterization. */
 +	          // Apply keyword parameterization.
  	          if (ptype == 'v') {
- 	            ipx = (wcsp->npv)++;
+-	            ipx = (wcsp->npv)++;
++	            int ipx = (wcsp->npv)++;
  	            wcsp->pv[ipx].i = i;
-@@ -29393,14 +29390,14 @@ YY_RULE_SETUP
+ 	            wcsp->pv[ipx].m = m;
+ 	            wptr = &(wcsp->pv[ipx].value);
+@@ -29393,14 +29354,14 @@ YY_RULE_SETUP
  	            *((double *)wptr) = dbltmp;
  	          }
  	
@@ -7547,57 +8486,69 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	            if (special) {
  	              special(wptr, dbl2tmp);
  	            } else {
-@@ -29409,7 +29406,7 @@ YY_RULE_SETUP
+@@ -29409,9 +29370,9 @@ YY_RULE_SETUP
  	            }
  	
  	        } else if (valtype == STRING) {
 -	          /* Apply keyword parameterization. */
 +	          // Apply keyword parameterization.
  	          if (ptype == 's') {
- 	            ipx = wcsp->nps++;
+-	            ipx = wcsp->nps++;
++	            int ipx = wcsp->nps++;
  	            wcsp->ps[ipx].i = i;
-@@ -29460,7 +29457,7 @@ case 421:
+ 	            wcsp->ps[ipx].m = m;
+ 	            wptr = wcsp->ps[ipx].value;
+@@ -29424,7 +29385,7 @@ YY_RULE_SETUP
+ 	            wptr = *((char (**)[72])wptr) + (i - 1);
+ 	          }
+ 	
+-	          cptr = (char *)wptr;
++	          char *cptr = (char *)wptr;
+ 	          strcpy(cptr, strtmp);
+ 	        }
+ 	      }
+@@ -29460,7 +29421,7 @@ case 421:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 2990 "wcsbth.l"
-+#line 2987 "wcsbth.l"
++#line 2954 "wcsbth.l"
  {
  	  errmsg = "invalid keyvalue";
  	  BEGIN(ERROR);
-@@ -29471,7 +29468,7 @@ case 422:
+@@ -29471,7 +29432,7 @@ case 422:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 2995 "wcsbth.l"
-+#line 2992 "wcsbth.l"
++#line 2959 "wcsbth.l"
  {
  	  errmsg = "invalid keyvalue";
  	  BEGIN(ERROR);
-@@ -29482,7 +29479,7 @@ case 423:
+@@ -29482,7 +29443,7 @@ case 423:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 3000 "wcsbth.l"
-+#line 2997 "wcsbth.l"
++#line 2964 "wcsbth.l"
  {
  	  errmsg = "invalid keyvalue or malformed keycomment";
  	  BEGIN(ERROR);
-@@ -29493,7 +29490,7 @@ case 424:
+@@ -29493,7 +29454,7 @@ case 424:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 3005 "wcsbth.l"
-+#line 3002 "wcsbth.l"
++#line 2969 "wcsbth.l"
  {
  	  errmsg = "malformed keycomment";
  	  BEGIN(ERROR);
-@@ -29504,11 +29501,11 @@ case 425:
+@@ -29504,11 +29465,11 @@ case 425:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 3010 "wcsbth.l"
-+#line 3007 "wcsbth.l"
++#line 2974 "wcsbth.l"
  {
  	  if (ipass == npass) {
  	    if (ctrl < 0) {
@@ -7606,25 +8557,25 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	      keep = keyrec;
  	
  	    } else if (2 < ctrl) {
-@@ -29525,7 +29522,7 @@ case 426:
+@@ -29525,7 +29486,7 @@ case 426:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 3025 "wcsbth.l"
-+#line 3022 "wcsbth.l"
++#line 2989 "wcsbth.l"
  {
  	  if (ipass == npass) {
  	    (*nreject)++;
-@@ -29545,7 +29542,7 @@ YY_RULE_SETUP
+@@ -29545,7 +29506,7 @@ YY_RULE_SETUP
  case 427:
  /* rule 427 can match eol */
  YY_RULE_SETUP
 -#line 3041 "wcsbth.l"
-+#line 3038 "wcsbth.l"
++#line 3005 "wcsbth.l"
  {
  	  if (ipass == npass && keep) {
  	    if (hptr < keep) {
-@@ -29556,7 +29553,7 @@ YY_RULE_SETUP
+@@ -29556,7 +29517,7 @@ YY_RULE_SETUP
  	
  	  naux += auxprm;
  	
@@ -7633,50 +8584,98 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
  	  i = j = 0;
  	  n = k = 0;
  	  m = 0;
-@@ -29611,9 +29608,9 @@ case YY_STATE_EOF(COMMENT):
+@@ -29611,10 +29572,11 @@ case YY_STATE_EOF(COMMENT):
  case YY_STATE_EOF(DISCARD):
  case YY_STATE_EOF(ERROR):
  case YY_STATE_EOF(FLUSH):
 -#line 3072 "wcsbth.l"
-+#line 3069 "wcsbth.l"
++#line 3036 "wcsbth.l"
  {
 -	  /* End-of-input. */
 +	  // End-of-input.
  	  if (ipass == 1) {
++	    int status;
  	    if ((status = wcsbth_init1(&alts, naux, nwcs, wcs)) ||
  	        (*nwcs == 0 && ctrl == 0)) {
-@@ -29682,10 +29679,10 @@ case YY_STATE_EOF(FLUSH):
+ 	      return status;
+@@ -29635,8 +29597,8 @@ case YY_STATE_EOF(FLUSH):
+ 	  }
+ 	
+ 	  if (ipass++ < npass) {
+-	    wcsbth_hdr = header;
+-	    wcsbth_nkeyrec = nkeyrec;
++	    yyextra->hdr = header;
++	    yyextra->nkeyrec = nkeyrec;
+ 	    keyrec = header;
+ 	    *nreject = 0;
+ 	
+@@ -29682,10 +29644,10 @@ case YY_STATE_EOF(FLUSH):
  	YY_BREAK
  case 428:
  YY_RULE_SETUP
 -#line 3140 "wcsbth.l"
-+#line 3137 "wcsbth.l"
++#line 3105 "wcsbth.l"
  ECHO;
  	YY_BREAK
 -#line 29689 "wcsbth.c"
-+#line 29686 "wcsbth.c"
++#line 29651 "wcsbth.c"
  
  	case YY_END_OF_BUFFER:
  		{
-@@ -30850,7 +30847,7 @@ void yyfree (void * ptr , yyscan_t yysca
+@@ -30850,8 +30812,38 @@ void yyfree (void * ptr , yyscan_t yysca
  
  #define YYTABLES_NAME "yytables"
  
 -#line 3140 "wcsbth.l"
-+#line 3137 "wcsbth.l"
++#line 3105 "wcsbth.l"
++
++
++/*----------------------------------------------------------------------------
++* External interface to the scanner.
++*---------------------------------------------------------------------------*/
++
++int wcsbth(
++  char *header,
++  int nkeyrec,
++  int relax,
++  int ctrl,
++  int keysel,
++  int *colsel,
++  int *nreject,
++  int *nwcs,
++  struct wcsprm **wcs)
++
++{
++  // Function prototypes.
++  int yylex_init_extra(YY_EXTRA_TYPE extra, yyscan_t *yyscanner);
++  int yylex_destroy(yyscan_t yyscanner);
++
++  struct wcsbth_extra extra;
++  yyscan_t yyscanner;
++  yylex_init_extra(&extra, &yyscanner);
++  int status = wcsbth_scanner(header, nkeyrec, relax, ctrl, keysel, colsel,
++                              nreject, nwcs, wcs, yyscanner);
++  yylex_destroy(yyscanner);
  
++  return status;
++}
  
  /*----------------------------------------------------------------------------
-@@ -30893,20 +30890,20 @@ int wcsbth_pass1(
-   int ialt, icol, mask, ncol;
+ * Perform first-pass tasks:
+@@ -30890,23 +30882,21 @@ int wcsbth_pass1(
+   struct wcsbth_alts *alts)
  
+ {
+-  int ialt, icol, mask, ncol;
+-
    if (a == 0) {
 -    /* Keywords such as DATE-OBS go along for the ride. */
 +    // Keywords such as DATE-OBS go along for the ride.
      return 0;
    }
  
-   ncol = alts->ncol;
+-  ncol = alts->ncol;
++  int ncol = alts->ncol;
  
 -  /* Do we need to allocate memory for alts? */
 +  // Do we need to allocate memory for alts?
@@ -7694,7 +8693,14 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
          ncol = 999;
        }
      }
-@@ -30925,7 +30922,7 @@ int wcsbth_pass1(
+@@ -30919,13 +30909,13 @@ int wcsbth_pass1(
+       if (alts->npv)     free(alts->npv);
+       if (alts->nps)     free(alts->nps);
+       if (alts->pixlist) free(alts->pixlist);
+-      return 2;
++      return WCSHDRERR_MEMORY;
+     }
+ 
      alts->ncol = ncol;
  
    } else if (n > ncol || k > ncol) {
@@ -7703,16 +8709,30 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
      ncol = 999;
      if (!(alts->arridx  = realloc(alts->arridx,
                                      27*(1 + ncol)*sizeof(short int))) ||
-@@ -30942,7 +30939,7 @@ int wcsbth_pass1(
-       return 2;
+@@ -30939,12 +30929,12 @@ int wcsbth_pass1(
+       if (alts->npv)     free(alts->npv);
+       if (alts->nps)     free(alts->nps);
+       if (alts->pixlist) free(alts->pixlist);
+-      return 2;
++      return WCSHDRERR_MEMORY;
      }
  
 -    /* Since realloc() doesn't initialize the extra memory. */
+-    for (icol = (1 + alts->ncol); icol < (1 + ncol); icol++) {
+-      for (ialt = 0; ialt < 27; ialt++) {
 +    // Since realloc() doesn't initialize the extra memory.
-     for (icol = (1 + alts->ncol); icol < (1 + ncol); icol++) {
-       for (ialt = 0; ialt < 27; ialt++) {
++    for (int icol = (1 + alts->ncol); icol < (1 + ncol); icol++) {
++      for (int ialt = 0; ialt < 27; ialt++) {
          alts->arridx[icol][ialt] = 0;
-@@ -30960,18 +30957,18 @@ int wcsbth_pass1(
+         alts->npv[icol][ialt] = 0;
+         alts->nps[icol][ialt] = 0;
+@@ -30955,23 +30945,23 @@ int wcsbth_pass1(
+     alts->ncol = ncol;
+   }
+ 
+-  ialt = 0;
++  int ialt = 0;
+   if (a != ' ') {
      ialt = a - 'A' + 1;
    }
  
@@ -7736,7 +8756,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
        if (alts->arridx[n][ialt] < i) {
          alts->arridx[n][ialt] = i;
        }
-@@ -30988,17 +30985,17 @@ int wcsbth_pass1(
+@@ -30988,17 +30978,17 @@ int wcsbth_pass1(
      }
    }
  
@@ -7747,7 +8767,8 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
 +  // image arrays, never contribute to recognizing a table column as a pixel
 +  // list axis.  A PIXLIST keytype is required for that.
    if (keytype == PIXLIST) {
-     mask = 1 << ialt;
+-    mask = 1 << ialt;
++    int mask = 1 << ialt;
  
 -    /* n > 0 for PIXLIST keytypes. */
 +    // n > 0 for PIXLIST keytypes.
@@ -7759,16 +8780,34 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
      alts->pixlist[0] |= mask;
  
      if (ptype == 'v') {
-@@ -31035,7 +31032,7 @@ int wcsbth_init1(
+@@ -31026,22 +31016,20 @@ int wcsbth_init1(
+   struct wcsprm **wcs)
+ 
+ {
+-  int ialt, icol, inherit[27], ix, mask, ncol, npsmax, npvmax, status = 0;
+-  struct wcsprm *wcsp;
+-
++  int status = 0;
+ 
+   if (alts->arridx == 0x0) {
+     *nwcs = 0;
      return 0;
    }
  
 -  /* Determine the number of axes in each pixel list representation. */
+-  ncol = alts->ncol;
 +  // Determine the number of axes in each pixel list representation.
-   ncol = alts->ncol;
++  int ialt, mask, ncol = alts->ncol;
    for (ialt = 0, mask = 1; ialt < 27; ialt++, mask <<= 1) {
      alts->pixidx[ialt] = 0;
-@@ -31049,7 +31046,7 @@ int wcsbth_init1(
+ 
+     if (alts->pixlist[0] | mask) {
+-      for (icol = 1; icol <= ncol; icol++) {
++      for (int icol = 1; icol <= ncol; icol++) {
+         if (alts->pixlist[icol] & mask) {
+           alts->pixidx[ialt]++;
+         }
+@@ -31049,18 +31037,19 @@ int wcsbth_init1(
      }
    }
  
@@ -7776,10 +8815,13 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
 +  // Find the total number of coordinate representations.
    *nwcs = 0;
    alts->imgherit = 0;
-   for (ialt = 0; ialt < 27; ialt++) {
-@@ -31057,10 +31054,10 @@ int wcsbth_init1(
+-  for (ialt = 0; ialt < 27; ialt++) {
++  int inherit[27];
++  for (int ialt = 0; ialt < 27; ialt++) {
+     inherit[ialt] = 0;
  
-     for (icol = 1; icol <= ncol; icol++) {
+-    for (icol = 1; icol <= ncol; icol++) {
++    for (int icol = 1; icol <= ncol; icol++) {
        if (alts->arridx[icol][ialt] < 0) {
 -        /* No BIMGARR keytype but there's at least one BINTAB. */
 +        // No BIMGARR keytype but there's at least one BINTAB.
@@ -7791,7 +8833,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
            alts->arridx[icol][ialt] = alts->arridx[0][ialt];
          } else {
            alts->arridx[icol][ialt] = 0;
-@@ -31069,11 +31066,11 @@ int wcsbth_init1(
+@@ -31069,11 +31058,11 @@ int wcsbth_init1(
  
        if (alts->arridx[icol][ialt]) {
          if (alts->arridx[0][ialt]) {
@@ -7805,7 +8847,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
              alts->arridx[icol][ialt] = alts->arridx[0][ialt];
            }
          }
-@@ -31082,10 +31079,10 @@ int wcsbth_init1(
+@@ -31082,10 +31071,10 @@ int wcsbth_init1(
        }
      }
  
@@ -7818,7 +8860,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
          alts->arridx[0][ialt] = 0;
          alts->imgherit = 1;
        } else if (alts->arridx[0][ialt] > 0) {
-@@ -31093,7 +31090,7 @@ int wcsbth_init1(
+@@ -31093,7 +31082,7 @@ int wcsbth_init1(
        }
      }
  
@@ -7827,31 +8869,39 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
      if (alts->pixidx[ialt]) {
        (*nwcs)++;
      }
-@@ -31101,19 +31098,19 @@ int wcsbth_init1(
+@@ -31101,95 +31090,95 @@ int wcsbth_init1(
  
  
    if (*nwcs) {
 -    /* Allocate memory for the required number of wcsprm structs. */
 +    // Allocate memory for the required number of wcsprm structs.
      if (!(*wcs = calloc(*nwcs, sizeof(struct wcsprm)))) {
-       return 2;
+-      return 2;
++      return WCSHDRERR_MEMORY;
      }
  
 -    /* Initialize each wcsprm struct. */
+-    wcsp = *wcs;
 +    // Initialize each wcsprm struct.
-     wcsp = *wcs;
++    struct wcsprm *wcsp = *wcs;
      *nwcs = 0;
-     for (icol = 0; icol <= ncol; icol++) {
-       for (ialt = 0; ialt < 27; ialt++) {
+-    for (icol = 0; icol <= ncol; icol++) {
+-      for (ialt = 0; ialt < 27; ialt++) {
++    for (int icol = 0; icol <= ncol; icol++) {
++      for (int ialt = 0; ialt < 27; ialt++) {
          if (alts->arridx[icol][ialt] > 0) {
 -          /* Image-header representations that are not for inheritance
 -             (icol == 0) or binary table image array representations. */
 +          // Image-header representations that are not for inheritance
 +          // (icol == 0) or binary table image array representations.
            wcsp->flag = -1;
-           npvmax = alts->npv[icol][ialt];
-           npsmax = alts->nps[icol][ialt];
-@@ -31123,29 +31120,29 @@ int wcsbth_init1(
+-          npvmax = alts->npv[icol][ialt];
+-          npsmax = alts->nps[icol][ialt];
++          int npvmax = alts->npv[icol][ialt];
++          int npsmax = alts->nps[icol][ialt];
+           if ((status = wcsinit(1, (int)(alts->arridx[icol][ialt]), wcsp,
+                                 npvmax, npsmax, -1))) {
+             wcsvfree(nwcs, wcs);
              break;
            }
  
@@ -7887,16 +8937,21 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
            alts->arridx[icol][ialt] = -1;
          }
        }
-@@ -31153,7 +31150,7 @@ int wcsbth_init1(
+     }
  
-     for (ialt = 0; ialt < 27; ialt++) {
+-    for (ialt = 0; ialt < 27; ialt++) {
++    for (int ialt = 0; ialt < 27; ialt++) {
        if (alts->pixidx[ialt]) {
 -        /* Pixel lists representations. */
 +        // Pixel lists representations.
          wcsp->flag = -1;
-         npvmax = alts->pixnpv[ialt];
-         npsmax = alts->pixnps[ialt];
-@@ -31163,19 +31160,19 @@ int wcsbth_init1(
+-        npvmax = alts->pixnpv[ialt];
+-        npsmax = alts->pixnps[ialt];
++        int npvmax = alts->pixnpv[ialt];
++        int npsmax = alts->pixnps[ialt];
+         if ((status = wcsinit(1, (int)(alts->pixidx[ialt]), wcsp, npvmax,
+                               npsmax, -1))) {
+           wcsvfree(nwcs, wcs);
            break;
          }
  
@@ -7915,11 +8970,12 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
          }
  
 -        /* Record the pixel list column numbers. */
+-        mask = (1 << ialt);
 +        // Record the pixel list column numbers.
-         mask = (1 << ialt);
++        int icol, ix, mask = (1 << ialt);
          for (icol = 1, ix = 0; icol <= ncol; icol++) {
            if (alts->pixlist[icol] & mask) {
-@@ -31183,13 +31180,13 @@ int wcsbth_init1(
+             wcsp->colax[ix++] = icol;
            }
          }
  
@@ -7935,9 +8991,16 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
          alts->pixidx[ialt] = -1;
        }
      }
-@@ -31219,22 +31216,22 @@ struct wcsprm *wcsbth_idx(
+@@ -31213,28 +31202,27 @@ struct wcsprm *wcsbth_idx(
  
-   iwcs = -1;
+ {
+   const char as[] = " ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+-  int iwcs;
+ 
+   if (!wcs) return 0x0;
+ 
+-  iwcs = -1;
++  int iwcs = -1;
    for (; iwcs < 0 && alts->ialt < 27; alts->ialt++) {
 -    /* Note that a == 0 applies to every alternate, otherwise this
 -       loop simply determines the appropriate value of alts->ialt. */
@@ -7964,7 +9027,27 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
        alts->icol = 0;
      }
  
-@@ -31286,7 +31283,7 @@ int wcsbth_colax(
+@@ -31259,17 +31247,14 @@ int wcsbth_colax(
+   char a)
+ 
+ {
+-  int ix;
+-  struct wcsprm *wcsp;
+-
+   if (!wcs) return 0;
+ 
+-  wcsp = wcs;
++  struct wcsprm *wcsp = wcs;
+   if (a != ' ') {
+     wcsp += alts->pixidx[a-'A'+1];
+   }
+ 
+-  for (ix = 0; ix < wcsp->naxis; ix++) {
++  for (int ix = 0; ix < wcsp->naxis; ix++) {
+     if (wcsp->colax[ix] == n) {
+       return ++ix;
+     }
+@@ -31286,7 +31271,7 @@ int wcsbth_colax(
  int wcsbth_jdref(double *mjdref, const double *jdref)
  
  {
@@ -7973,7 +9056,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
    if (undefined(mjdref[0] && undefined(mjdref[1]))) {
      mjdref[0] = jdref[0] - 2400000.0;
      mjdref[1] = jdref[1] - 0.5;
-@@ -31303,7 +31300,7 @@ int wcsbth_jdref(double *mjdref, const d
+@@ -31303,7 +31288,7 @@ int wcsbth_jdref(double *mjdref, const d
  int wcsbth_jdrefi(double *mjdref, const double *jdrefi)
  
  {
@@ -7982,7 +9065,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
    if (undefined(mjdref[0])) {
      mjdref[0] = *jdrefi - 2400000.5;
    }
-@@ -31315,7 +31312,7 @@ int wcsbth_jdrefi(double *mjdref, const
+@@ -31315,7 +31300,7 @@ int wcsbth_jdrefi(double *mjdref, const
  int wcsbth_jdreff(double *mjdref, const double *jdreff)
  
  {
@@ -7991,7 +9074,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
    if (undefined(mjdref[1])) {
      mjdref[1] = *jdreff;
    }
-@@ -31331,7 +31328,7 @@ int wcsbth_jdreff(double *mjdref, const
+@@ -31331,7 +31316,7 @@ int wcsbth_jdreff(double *mjdref, const
  int wcsbth_epoch(double *equinox, const double *epoch)
  
  {
@@ -8000,31 +9083,46 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsbth.c
    if (undefined(*equinox)) {
      *equinox = *epoch;
    }
-@@ -31349,9 +31346,9 @@ int wcsbth_vsource(double *zsource, cons
+@@ -31347,12 +31332,12 @@ int wcsbth_epoch(double *equinox, const
+ int wcsbth_vsource(double *zsource, const double *vsource)
+ 
  {
-   double beta, c = 299792458.0;
+-  double beta, c = 299792458.0;
++  const double c = 299792458.0;
  
 -  /* If ZSOURCEa is currently undefined then set it from VSOURCEa. */
 +  // If ZSOURCEa is currently undefined then set it from VSOURCEa.
    if (undefined(*zsource)) {
 -    /* Convert relativistic Doppler velocity to redshift. */
+-    beta = *vsource/c;
 +    // Convert relativistic Doppler velocity to redshift.
-     beta = *vsource/c;
++    double beta = *vsource/c;
      *zsource = (1.0 + beta)/sqrt(1.0 - beta*beta) - 1.0;
    }
-@@ -31389,7 +31386,7 @@ int wcsbth_final(
+ 
+@@ -31381,15 +31366,14 @@ int wcsbth_final(
+   struct wcsprm **wcs)
+ 
+ {
+-  int ialt, status;
+-
+   if (alts->arridx)  free(alts->arridx);
+   if (alts->npv)     free(alts->npv);
+   if (alts->nps)     free(alts->nps);
    if (alts->pixlist) free(alts->pixlist);
  
-   for (ialt = 0; ialt < *nwcs; ialt++) {
+-  for (ialt = 0; ialt < *nwcs; ialt++) {
 -    /* Interpret -TAB header keywords. */
++  for (int ialt = 0; ialt < *nwcs; ialt++) {
 +    // Interpret -TAB header keywords.
++    int status;
      if ((status = wcstab(*wcs+ialt))) {
         wcsvfree(nwcs, wcs);
         return status;
-Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
+Index: astropy-4.2.1/cextern/wcslib/C/flexed/wcspih.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/flexed/wcspih.c
-+++ astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/flexed/wcspih.c
++++ astropy-4.2.1/cextern/wcslib/C/flexed/wcspih.c
 @@ -20763,9 +20763,8 @@ static const yy_state_type yy_NUL_trans[
  #define YY_RESTORE_YY_MORE_OFFSET
  #line 1 "wcspih.l"
@@ -8032,7 +9130,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -8046,7 +9144,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcspih.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcspih.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcspih.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
  * wcspih.l is a Flex description file containing the definition of a lexical
@@ -8055,117 +9153,228 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  
  
 -#line 112 "wcspih.l"
-+#line 109 "wcspih.l"
++#line 110 "wcspih.l"
  #include <math.h>
  #include <setjmp.h>
  #include <stddef.h>
-@@ -20874,7 +20871,7 @@ static int wcspih_scanner(char *header,
-                           int *nreject, int *nwcs, struct wcsprm **wcs,
-                           yyscan_t yyscanner);
+@@ -20870,58 +20867,37 @@ static const yy_state_type yy_NUL_trans[
+ #define DSS     2
+ #define WAT     3
  
+-static int wcspih_scanner(char *header, int nkeyrec, int relax, int ctrl,
+-                          int *nreject, int *nwcs, struct wcsprm **wcs,
+-                          yyscan_t yyscanner);
+-
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
- 
- int wcspih(
-   char *header,
-@@ -20899,7 +20896,7 @@ int wcspih(
-   return status;
- }
- 
+-
+-int wcspih(
+-  char *header,
+-  int nkeyrec,
+-  int relax,
+-  int ctrl,
+-  int *nreject,
+-  int *nwcs,
+-  struct wcsprm **wcs)
+-
+-{
+-  int status;
+-  yyscan_t yyscanner;
+-  int yylex_init(yyscan_t *yyscanner);
+-  int yylex_destroy(yyscan_t yyscanner);
+-
+-  yylex_init(&yyscanner);
+-  status = wcspih_scanner(header, nkeyrec, relax, ctrl, nreject, nwcs, wcs,
+-                          yyscanner);
+-  yylex_destroy(yyscanner);
+-
+-  return status;
+-}
+-
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
++// User data associated with yyscanner.
++struct wcspih_extra {
++  // Values passed to YY_INPUT.
++  char *hdr;
++  int  nkeyrec;
++
++  // Used in preempting the call to exit() by yy_fatal_error().
++  jmp_buf abort_jmp_env;
++};
  
  #define YY_DECL int wcspih_scanner(char *header, int nkeyrec, int relax, \
   int ctrl, int *nreject, int *nwcs, struct wcsprm **wcs, yyscan_t yyscanner)
-@@ -20917,11 +20914,11 @@ int wcspih(
+ 
+ #define YY_INPUT(inbuff, count, bufsize) \
+ 	{ \
+-	  if (wcspih_nkeyrec) { \
+-	    strncpy(inbuff, wcspih_hdr, 80); \
++	  if (yyextra->nkeyrec) { \
++	    strncpy(inbuff, yyextra->hdr, 80); \
+ 	    inbuff[80] = '\n'; \
+-	    wcspih_hdr += 80; \
+-	    wcspih_nkeyrec--; \
++	    yyextra->hdr += 80; \
++	    yyextra->nkeyrec--; \
+ 	    count = 81; \
+ 	  } else { \
+ 	    count = YY_NULL; \
  	  } \
  	}
  
 -/* These global variables are required by YY_INPUT. */
-+// These global variables are required by YY_INPUT.
- static char *wcspih_hdr;
- static int  wcspih_nkeyrec;
+-static char *wcspih_hdr;
+-static int  wcspih_nkeyrec;
++// Preempt the call to exit() by yy_fatal_error().
++#define exit(status) longjmp(yyextra->abort_jmp_env, status);
  
 -/* Internal helper functions. */
 +// Internal helper functions.
++static YY_DECL;
  static int wcspih_final(int ndp[], int ndq[], int distran, double dsstmp[],
               char *wat[], int *nwcs, struct wcsprm **wcs);
  static int wcspih_init1(int naxis, int alts[], int dpq[], int npv[],
-@@ -20938,12 +20935,12 @@ static int wcspih_vsource(double *wptr,
+@@ -20938,12 +20914,8 @@ static int wcspih_vsource(double *wptr,
  
  static int wcspih_timepixr(double timepixr);
  
 -/* Used in preempting the call to exit() by yy_fatal_error(). */
-+// Used in preempting the call to exit() by yy_fatal_error().
- jmp_buf wcspih_abort_jmp_env;
- #define exit(status) longjmp(wcspih_abort_jmp_env, status)
- 
+-jmp_buf wcspih_abort_jmp_env;
+-#define exit(status) longjmp(wcspih_abort_jmp_env, status)
+-
 -#line 20946 "wcspih.c"
 -#line 20947 "wcspih.c"
-+#line 20943 "wcspih.c"
-+#line 20944 "wcspih.c"
++#line 20918 "wcspih.c"
++#line 20919 "wcspih.c"
  
  #define INITIAL 0
  #define CCia 1
-@@ -21216,10 +21213,10 @@ YY_DECL
+@@ -20981,9 +20953,7 @@ jmp_buf wcspih_abort_jmp_env;
+ #include <unistd.h>
+ #endif
+ 
+-#ifndef YY_EXTRA_TYPE
+-#define YY_EXTRA_TYPE void *
+-#endif
++#define YY_EXTRA_TYPE struct wcspih_extra *
+ 
+ /* Holds the entire state of the reentrant scanner. */
+ struct yyguts_t
+@@ -21216,30 +21186,20 @@ YY_DECL
  		}
  
  	{
 -#line 214 "wcspih.l"
-+#line 211 "wcspih.l"
++#line 187 "wcspih.l"
  
 -#line 216 "wcspih.l"
 -	/* Keyword indices, as used in the WCS papers, e.g. PCi_ja, PVi_ma. */
-+#line 213 "wcspih.l"
-+	// Keyword indices, as used in the WCS papers, e.g. PCi_ja, PVi_ma.
- 	char a;
- 	int  i, j, m, p, q;
+-	char a;
+-	int  i, j, m, p, q;
+-	
+-	char *cptr, *errmsg, errtxt[80], *hptr, *keep, *keyname, *keyrec,
+-	     keyword[16], strtmp[80], *wat[2], *watstr;
+-	int  altlin, alts[27], auxprm, distran, distype, dpq[27], dssflag,
+-	     gotone, ialt, inttmp, ipass, ipx, ix, jx, naux, naxis,
+-	     ndp[27], ndq[27], nother, *npptr, nps[27], npass, npv[27],
+-	     nvalid, rectype, sipflag, status, valtype, watflag, watn;
+-	ptrdiff_t voff;
++#line 189 "wcspih.l"
++	int  p, q;
++	char *errmsg, errtxt[80], *keyname, strtmp[80], *wat[2], *watstr;
++	int  alts[27], dpq[27], inttmp, ndp[27], ndq[27], nps[27], npv[27],
++	     rectype;
+ 	double dbltmp, dbl2tmp[2], dsstmp[20];
+-	void *vptr, *wptr;
+-	struct auxprm *auxp, auxtem;
+-	struct disprm *disp, distem;
+-	struct wcsprm *wcsp, wcstem;
+-	int (*chekval)(double);
+-	int (*special)(double *, const double *);
++	struct auxprm auxtem;
++	struct disprm distem;
++	struct wcsprm wcstem;
  	
-@@ -21248,34 +21245,34 @@ YY_DECL
+-	naxis = 0;
+-	for (ialt = 0; ialt < 27; ialt++) {
++	int naxis = 0;
++	for (int ialt = 0; ialt < 27; ialt++) {
+ 	  alts[ialt] = 0;
+ 	  dpq[ialt]  = 0;
+ 	  npv[ialt]  = 0;
+@@ -21248,63 +21208,64 @@ YY_DECL
  	  ndq[ialt]  = 0;
  	}
  	
 -	/* Parameters used to implement YY_INPUT. */
-+	// Parameters used to implement YY_INPUT.
- 	wcspih_hdr = header;
- 	wcspih_nkeyrec = nkeyrec;
- 	
+-	wcspih_hdr = header;
+-	wcspih_nkeyrec = nkeyrec;
+-	
 -	/* Our handle on the input stream. */
+-	keyrec = header;
+-	hptr = header;
+-	keep = 0x0;
 +	// Our handle on the input stream.
- 	keyrec = header;
- 	hptr = header;
- 	keep = 0x0;
++	char *keyrec = header;
++	char *hptr = header;
++	char *keep = 0x0;
  	
 -	/* For keeping tallies of keywords found. */
 +	// For keeping tallies of keywords found.
  	*nreject = 0;
- 	nvalid = 0;
- 	nother = 0;
+-	nvalid = 0;
+-	nother = 0;
++	int nvalid = 0;
++	int nother = 0;
  	
 -	/* If strict, then also reject. */
 +	// If strict, then also reject.
  	if (relax & WCSHDR_strict) relax |= WCSHDR_reject;
  	
 -	/* Keyword parameters. */
-+	// Keyword parameters.
- 	i = j = 0;
- 	m = 0;
- 	a = ' ';
- 	
+-	i = j = 0;
+-	m = 0;
+-	a = ' ';
+-	
 -	/* For decoding the keyvalue. */
-+	// For decoding the keyvalue.
- 	valtype = -1;
- 	distype =  0;
- 	vptr    = 0x0;
- 	
+-	valtype = -1;
+-	distype =  0;
+-	vptr    = 0x0;
+-	
 -	/* For keywords that require special handling. */
+-	altlin  = 0;
+-	npptr   = 0x0;
+-	chekval = 0x0;
+-	special = 0x0;
+-	auxprm  = 0;
+-	naux    = 0;
+-	distran = 0;
+-	sipflag = 0;
+-	dssflag = 0;
+-	watflag = 0;
+-	watn    = 0;
++	// Keyword indices, as used in the WCS papers, e.g. PCi_ja, PVi_ma.
++	int i = 0;
++	int j = 0;
++	int m = 0;
++	char a = ' ';
++	
++	// For decoding the keyvalue.
++	int valtype = -1;
++	int distype =  0;
++	void *vptr  = 0x0;
++	
 +	// For keywords that require special handling.
- 	altlin  = 0;
- 	npptr   = 0x0;
- 	chekval = 0x0;
-@@ -21288,15 +21285,15 @@ YY_DECL
- 	watflag = 0;
- 	watn    = 0;
++	int altlin  = 0;
++	int *npptr  = 0x0;
++	int (*chekval)(double) = 0x0;
++	int (*special)(double *, const double *) = 0x0;
++	int auxprm  = 0;
++	int naux    = 0;
++	int distran = 0;
++	int sipflag = 0;
++	int dssflag = 0;
++	int watflag = 0;
++	int watn    = 0;
  	
 -	/* The data structures produced. */
 +	// The data structures produced.
@@ -8173,330 +9382,339 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	*wcs  = 0x0;
  	
 -	/* Control variables. */
-+	// Control variables.
- 	ipass = 1;
- 	npass = 2;
- 	
+-	ipass = 1;
+-	npass = 2;
+-	
 -	/* Return here via longjmp() invoked by yy_fatal_error(). */
+-	if (setjmp(wcspih_abort_jmp_env)) {
+-	  return 3;
++	// Control variables.
++	int ipass = 1;
++	int npass = 2;
++	
++	// User data associated with yyscanner.
++	yyextra->hdr = header;
++	yyextra->nkeyrec = nkeyrec;
++	
 +	// Return here via longjmp() invoked by yy_fatal_error().
- 	if (setjmp(wcspih_abort_jmp_env)) {
- 	  return 3;
++	if (setjmp(yyextra->abort_jmp_env)) {
++	  return WCSHDRERR_PARSER;
  	}
-@@ -21304,7 +21301,7 @@ YY_DECL
+ 	
  	BEGIN(INITIAL);
  
  
 -#line 21308 "wcspih.c"
-+#line 21305 "wcspih.c"
++#line 21269 "wcspih.c"
  
  	while ( /*CONSTCOND*/1 )		/* loops until end-of-file is reached */
  		{
-@@ -21352,7 +21349,7 @@ do_action:	/* This label is used only to
+@@ -21352,7 +21313,7 @@ do_action:	/* This label is used only to
  
  case 1:
  YY_RULE_SETUP
 -#line 301 "wcspih.l"
-+#line 298 "wcspih.l"
++#line 265 "wcspih.l"
  {
  	  keyname = "NAXISn";
  	
-@@ -21375,7 +21372,7 @@ YY_RULE_SETUP
+@@ -21375,7 +21336,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 2:
  YY_RULE_SETUP
 -#line 321 "wcspih.l"
-+#line 318 "wcspih.l"
++#line 285 "wcspih.l"
  {
  	  sscanf(yytext, "WCSAXES%c= %d", &a, &i);
  	
-@@ -21394,7 +21391,7 @@ YY_RULE_SETUP
+@@ -21394,7 +21355,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 3:
  YY_RULE_SETUP
 -#line 337 "wcspih.l"
-+#line 334 "wcspih.l"
++#line 301 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.crpix);
-@@ -21405,7 +21402,7 @@ YY_RULE_SETUP
+@@ -21405,7 +21366,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 4:
  YY_RULE_SETUP
 -#line 345 "wcspih.l"
-+#line 342 "wcspih.l"
++#line 309 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.pc);
-@@ -21417,7 +21414,7 @@ YY_RULE_SETUP
+@@ -21417,7 +21378,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 5:
  YY_RULE_SETUP
 -#line 354 "wcspih.l"
-+#line 351 "wcspih.l"
++#line 318 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.cd);
-@@ -21429,7 +21426,7 @@ YY_RULE_SETUP
+@@ -21429,7 +21390,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 6:
  YY_RULE_SETUP
 -#line 363 "wcspih.l"
-+#line 360 "wcspih.l"
++#line 327 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.cdelt);
-@@ -21440,7 +21437,7 @@ YY_RULE_SETUP
+@@ -21440,7 +21401,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 7:
  YY_RULE_SETUP
 -#line 371 "wcspih.l"
-+#line 368 "wcspih.l"
++#line 335 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.crota);
-@@ -21452,7 +21449,7 @@ YY_RULE_SETUP
+@@ -21452,7 +21413,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 8:
  YY_RULE_SETUP
 -#line 380 "wcspih.l"
-+#line 377 "wcspih.l"
++#line 344 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = &(wcstem.cunit);
-@@ -21463,7 +21460,7 @@ YY_RULE_SETUP
+@@ -21463,7 +21424,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 9:
  YY_RULE_SETUP
 -#line 388 "wcspih.l"
-+#line 385 "wcspih.l"
++#line 352 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = &(wcstem.ctype);
-@@ -21474,7 +21471,7 @@ YY_RULE_SETUP
+@@ -21474,7 +21435,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 10:
  YY_RULE_SETUP
 -#line 396 "wcspih.l"
-+#line 393 "wcspih.l"
++#line 360 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.crval);
-@@ -21485,7 +21482,7 @@ YY_RULE_SETUP
+@@ -21485,7 +21446,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 11:
  YY_RULE_SETUP
 -#line 404 "wcspih.l"
-+#line 401 "wcspih.l"
++#line 368 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.lonpole);
-@@ -21496,7 +21493,7 @@ YY_RULE_SETUP
+@@ -21496,7 +21457,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 12:
  YY_RULE_SETUP
 -#line 412 "wcspih.l"
-+#line 409 "wcspih.l"
++#line 376 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.latpole);
-@@ -21507,7 +21504,7 @@ YY_RULE_SETUP
+@@ -21507,7 +21468,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 13:
  YY_RULE_SETUP
 -#line 420 "wcspih.l"
-+#line 417 "wcspih.l"
++#line 384 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.restfrq);
-@@ -21518,7 +21515,7 @@ YY_RULE_SETUP
+@@ -21518,7 +21479,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 14:
  YY_RULE_SETUP
 -#line 428 "wcspih.l"
-+#line 425 "wcspih.l"
++#line 392 "wcspih.l"
  {
  	  if (relax & WCSHDR_strict) {
  	    errmsg = "the RESTFREQ keyword is deprecated, use RESTFRQa";
-@@ -21537,7 +21534,7 @@ YY_RULE_SETUP
+@@ -21537,7 +21498,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 15:
  YY_RULE_SETUP
 -#line 444 "wcspih.l"
-+#line 441 "wcspih.l"
++#line 408 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.restwav);
-@@ -21548,7 +21545,7 @@ YY_RULE_SETUP
+@@ -21548,7 +21509,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 16:
  YY_RULE_SETUP
 -#line 452 "wcspih.l"
-+#line 449 "wcspih.l"
++#line 416 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.pv);
-@@ -21560,7 +21557,7 @@ YY_RULE_SETUP
+@@ -21560,7 +21521,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 17:
  YY_RULE_SETUP
 -#line 461 "wcspih.l"
-+#line 458 "wcspih.l"
++#line 425 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.pv);
-@@ -21572,7 +21569,7 @@ YY_RULE_SETUP
+@@ -21572,7 +21533,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 18:
  YY_RULE_SETUP
 -#line 470 "wcspih.l"
-+#line 467 "wcspih.l"
++#line 434 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = &(wcstem.ps);
-@@ -21584,7 +21581,7 @@ YY_RULE_SETUP
+@@ -21584,7 +21545,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 19:
  YY_RULE_SETUP
 -#line 479 "wcspih.l"
-+#line 476 "wcspih.l"
++#line 443 "wcspih.l"
  {
  	  sscanf(yytext, "VELREF%c", &a);
  	
-@@ -21612,7 +21609,7 @@ YY_RULE_SETUP
+@@ -21612,7 +21573,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 20:
  YY_RULE_SETUP
 -#line 504 "wcspih.l"
-+#line 501 "wcspih.l"
++#line 468 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = &(wcstem.cname);
-@@ -21623,7 +21620,7 @@ YY_RULE_SETUP
+@@ -21623,7 +21584,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 21:
  YY_RULE_SETUP
 -#line 512 "wcspih.l"
-+#line 509 "wcspih.l"
++#line 476 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.crder);
-@@ -21634,7 +21631,7 @@ YY_RULE_SETUP
+@@ -21634,7 +21595,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 22:
  YY_RULE_SETUP
 -#line 520 "wcspih.l"
-+#line 517 "wcspih.l"
++#line 484 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.csyer);
-@@ -21645,7 +21642,7 @@ YY_RULE_SETUP
+@@ -21645,7 +21606,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 23:
  YY_RULE_SETUP
 -#line 528 "wcspih.l"
-+#line 525 "wcspih.l"
++#line 492 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.czphs);
-@@ -21656,7 +21653,7 @@ YY_RULE_SETUP
+@@ -21656,7 +21617,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 24:
  YY_RULE_SETUP
 -#line 536 "wcspih.l"
-+#line 533 "wcspih.l"
++#line 500 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.cperi);
-@@ -21667,7 +21664,7 @@ YY_RULE_SETUP
+@@ -21667,7 +21628,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 25:
  YY_RULE_SETUP
 -#line 544 "wcspih.l"
-+#line 541 "wcspih.l"
++#line 508 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.wcsname;
-@@ -21678,7 +21675,7 @@ YY_RULE_SETUP
+@@ -21678,7 +21639,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 26:
  YY_RULE_SETUP
 -#line 552 "wcspih.l"
-+#line 549 "wcspih.l"
++#line 516 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.timesys;
-@@ -21689,7 +21686,7 @@ YY_RULE_SETUP
+@@ -21689,7 +21650,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 27:
  YY_RULE_SETUP
 -#line 560 "wcspih.l"
-+#line 557 "wcspih.l"
++#line 524 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.trefpos;
-@@ -21700,7 +21697,7 @@ YY_RULE_SETUP
+@@ -21700,7 +21661,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 28:
  YY_RULE_SETUP
 -#line 568 "wcspih.l"
-+#line 565 "wcspih.l"
++#line 532 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.trefdir;
-@@ -21711,7 +21708,7 @@ YY_RULE_SETUP
+@@ -21711,7 +21672,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 29:
  YY_RULE_SETUP
 -#line 576 "wcspih.l"
-+#line 573 "wcspih.l"
++#line 540 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.plephem;
-@@ -21722,7 +21719,7 @@ YY_RULE_SETUP
+@@ -21722,7 +21683,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 30:
  YY_RULE_SETUP
 -#line 584 "wcspih.l"
-+#line 581 "wcspih.l"
++#line 548 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.timeunit;
-@@ -21732,10 +21729,10 @@ YY_RULE_SETUP
+@@ -21732,10 +21693,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 31:
 -#line 593 "wcspih.l"
-+#line 590 "wcspih.l"
++#line 557 "wcspih.l"
  case 32:
  YY_RULE_SETUP
 -#line 593 "wcspih.l"
-+#line 590 "wcspih.l"
++#line 557 "wcspih.l"
  {
  	  if ((yytext[4] == 'R') || (relax & WCSHDR_DATEREF)) {
  	    valtype = STRING;
-@@ -21754,10 +21751,10 @@ YY_RULE_SETUP
+@@ -21754,10 +21715,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 33:
 -#line 611 "wcspih.l"
-+#line 608 "wcspih.l"
++#line 575 "wcspih.l"
  case 34:
  YY_RULE_SETUP
 -#line 611 "wcspih.l"
-+#line 608 "wcspih.l"
++#line 575 "wcspih.l"
  {
  	  if ((yytext[3] == 'R') || (relax & WCSHDR_DATEREF)) {
  	    valtype = FLOAT2;
-@@ -21776,13 +21773,13 @@ YY_RULE_SETUP
+@@ -21776,13 +21737,13 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 35:
 -#line 629 "wcspih.l"
-+#line 626 "wcspih.l"
++#line 593 "wcspih.l"
  case 36:
  YY_RULE_SETUP
 -#line 629 "wcspih.l"
-+#line 626 "wcspih.l"
++#line 593 "wcspih.l"
  {
  	  if ((yytext[3] == 'R') || (relax & WCSHDR_DATEREF)) {
 -	    /* Actually integer, but treated as float. */
@@ -8504,42 +9722,42 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	    valtype = FLOAT;
  	    vptr    = wcstem.mjdref;
  	
-@@ -21799,10 +21796,10 @@ YY_RULE_SETUP
+@@ -21799,10 +21760,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 37:
 -#line 648 "wcspih.l"
-+#line 645 "wcspih.l"
++#line 612 "wcspih.l"
  case 38:
  YY_RULE_SETUP
 -#line 648 "wcspih.l"
-+#line 645 "wcspih.l"
++#line 612 "wcspih.l"
  {
  	  if ((yytext[3] == 'R') || (relax & WCSHDR_DATEREF)) {
  	    valtype = FLOAT;
-@@ -21821,10 +21818,10 @@ YY_RULE_SETUP
+@@ -21821,10 +21782,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 39:
 -#line 666 "wcspih.l"
-+#line 663 "wcspih.l"
++#line 630 "wcspih.l"
  case 40:
  YY_RULE_SETUP
 -#line 666 "wcspih.l"
-+#line 663 "wcspih.l"
++#line 630 "wcspih.l"
  {
  	  if ((yytext[2] == 'R') || (relax & WCSHDR_DATEREF)) {
  	    valtype = FLOAT2;
-@@ -21844,13 +21841,13 @@ YY_RULE_SETUP
+@@ -21844,13 +21805,13 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 41:
 -#line 685 "wcspih.l"
-+#line 682 "wcspih.l"
++#line 649 "wcspih.l"
  case 42:
  YY_RULE_SETUP
 -#line 685 "wcspih.l"
-+#line 682 "wcspih.l"
++#line 649 "wcspih.l"
  {
  	  if ((yytext[2] == 'R') || (relax & WCSHDR_DATEREF)) {
 -	    /* Actually integer, but treated as float. */
@@ -8547,820 +9765,825 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	    valtype = FLOAT;
  	    vptr    = wcstem.mjdref;
  	    special = wcspih_jdrefi;
-@@ -21868,10 +21865,10 @@ YY_RULE_SETUP
+@@ -21868,10 +21829,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 43:
 -#line 705 "wcspih.l"
-+#line 702 "wcspih.l"
++#line 669 "wcspih.l"
  case 44:
  YY_RULE_SETUP
 -#line 705 "wcspih.l"
-+#line 702 "wcspih.l"
++#line 669 "wcspih.l"
  {
  	  if ((yytext[2] == 'R') || (relax & WCSHDR_DATEREF)) {
  	    valtype = FLOAT;
-@@ -21892,7 +21889,7 @@ YY_RULE_SETUP
+@@ -21892,7 +21853,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 45:
  YY_RULE_SETUP
 -#line 723 "wcspih.l"
-+#line 720 "wcspih.l"
++#line 687 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.timeoffs);
-@@ -21903,7 +21900,7 @@ YY_RULE_SETUP
+@@ -21903,7 +21864,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 46:
  YY_RULE_SETUP
 -#line 731 "wcspih.l"
-+#line 728 "wcspih.l"
++#line 695 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.dateobs;
-@@ -21915,7 +21912,7 @@ YY_RULE_SETUP
+@@ -21915,7 +21876,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 47:
  YY_RULE_SETUP
 -#line 740 "wcspih.l"
-+#line 737 "wcspih.l"
++#line 704 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.datebeg;
-@@ -21927,7 +21924,7 @@ YY_RULE_SETUP
+@@ -21927,7 +21888,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 48:
  YY_RULE_SETUP
 -#line 749 "wcspih.l"
-+#line 746 "wcspih.l"
++#line 713 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.dateavg;
-@@ -21939,7 +21936,7 @@ YY_RULE_SETUP
+@@ -21939,7 +21900,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 49:
  YY_RULE_SETUP
 -#line 758 "wcspih.l"
-+#line 755 "wcspih.l"
++#line 722 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.dateend;
-@@ -21951,7 +21948,7 @@ YY_RULE_SETUP
+@@ -21951,7 +21912,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 50:
  YY_RULE_SETUP
 -#line 767 "wcspih.l"
-+#line 764 "wcspih.l"
++#line 731 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.mjdobs);
-@@ -21963,7 +21960,7 @@ YY_RULE_SETUP
+@@ -21963,7 +21924,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 51:
  YY_RULE_SETUP
 -#line 776 "wcspih.l"
-+#line 773 "wcspih.l"
++#line 740 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.mjdbeg);
-@@ -21975,7 +21972,7 @@ YY_RULE_SETUP
+@@ -21975,7 +21936,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 52:
  YY_RULE_SETUP
 -#line 785 "wcspih.l"
-+#line 782 "wcspih.l"
++#line 749 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.mjdavg);
-@@ -21987,7 +21984,7 @@ YY_RULE_SETUP
+@@ -21987,7 +21948,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 53:
  YY_RULE_SETUP
 -#line 794 "wcspih.l"
-+#line 791 "wcspih.l"
++#line 758 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.mjdend);
-@@ -21999,7 +21996,7 @@ YY_RULE_SETUP
+@@ -21999,7 +21960,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 54:
  YY_RULE_SETUP
 -#line 803 "wcspih.l"
-+#line 800 "wcspih.l"
++#line 767 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.jepoch);
-@@ -22011,7 +22008,7 @@ YY_RULE_SETUP
+@@ -22011,7 +21972,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 55:
  YY_RULE_SETUP
 -#line 812 "wcspih.l"
-+#line 809 "wcspih.l"
++#line 776 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.bepoch);
-@@ -22023,7 +22020,7 @@ YY_RULE_SETUP
+@@ -22023,7 +21984,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 56:
  YY_RULE_SETUP
 -#line 821 "wcspih.l"
-+#line 818 "wcspih.l"
++#line 785 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.tstart);
-@@ -22035,7 +22032,7 @@ YY_RULE_SETUP
+@@ -22035,7 +21996,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 57:
  YY_RULE_SETUP
 -#line 830 "wcspih.l"
-+#line 827 "wcspih.l"
++#line 794 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.tstop);
-@@ -22047,7 +22044,7 @@ YY_RULE_SETUP
+@@ -22047,7 +22008,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 58:
  YY_RULE_SETUP
 -#line 839 "wcspih.l"
-+#line 836 "wcspih.l"
++#line 803 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.xposure);
-@@ -22059,7 +22056,7 @@ YY_RULE_SETUP
+@@ -22059,7 +22020,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 59:
  YY_RULE_SETUP
 -#line 848 "wcspih.l"
-+#line 845 "wcspih.l"
++#line 812 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.telapse);
-@@ -22071,7 +22068,7 @@ YY_RULE_SETUP
+@@ -22071,7 +22032,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 60:
  YY_RULE_SETUP
 -#line 857 "wcspih.l"
-+#line 854 "wcspih.l"
++#line 821 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.timsyer);
-@@ -22083,7 +22080,7 @@ YY_RULE_SETUP
+@@ -22083,7 +22044,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 61:
  YY_RULE_SETUP
 -#line 866 "wcspih.l"
-+#line 863 "wcspih.l"
++#line 830 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.timrder);
-@@ -22095,7 +22092,7 @@ YY_RULE_SETUP
+@@ -22095,7 +22056,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 62:
  YY_RULE_SETUP
 -#line 875 "wcspih.l"
-+#line 872 "wcspih.l"
++#line 839 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.timedel);
-@@ -22107,7 +22104,7 @@ YY_RULE_SETUP
+@@ -22107,7 +22068,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 63:
  YY_RULE_SETUP
 -#line 884 "wcspih.l"
-+#line 881 "wcspih.l"
++#line 848 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.timepixr);
-@@ -22120,7 +22117,7 @@ YY_RULE_SETUP
+@@ -22120,7 +22081,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 64:
  YY_RULE_SETUP
 -#line 894 "wcspih.l"
-+#line 891 "wcspih.l"
++#line 858 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = wcstem.obsgeo;
-@@ -22132,7 +22129,7 @@ YY_RULE_SETUP
+@@ -22132,7 +22093,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 65:
  YY_RULE_SETUP
 -#line 903 "wcspih.l"
-+#line 900 "wcspih.l"
++#line 867 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = wcstem.obsgeo + 1;
-@@ -22144,7 +22141,7 @@ YY_RULE_SETUP
+@@ -22144,7 +22105,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 66:
  YY_RULE_SETUP
 -#line 912 "wcspih.l"
-+#line 909 "wcspih.l"
++#line 876 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = wcstem.obsgeo + 2;
-@@ -22156,7 +22153,7 @@ YY_RULE_SETUP
+@@ -22156,7 +22117,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 67:
  YY_RULE_SETUP
 -#line 921 "wcspih.l"
-+#line 918 "wcspih.l"
++#line 885 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = wcstem.obsgeo + 3;
-@@ -22168,7 +22165,7 @@ YY_RULE_SETUP
+@@ -22168,7 +22129,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 68:
  YY_RULE_SETUP
 -#line 930 "wcspih.l"
-+#line 927 "wcspih.l"
++#line 894 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = wcstem.obsgeo + 4;
-@@ -22180,7 +22177,7 @@ YY_RULE_SETUP
+@@ -22180,7 +22141,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 69:
  YY_RULE_SETUP
 -#line 939 "wcspih.l"
-+#line 936 "wcspih.l"
++#line 903 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = wcstem.obsgeo + 5;
-@@ -22192,7 +22189,7 @@ YY_RULE_SETUP
+@@ -22192,7 +22153,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 70:
  YY_RULE_SETUP
 -#line 948 "wcspih.l"
-+#line 945 "wcspih.l"
++#line 912 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.obsorbit;
-@@ -22203,7 +22200,7 @@ YY_RULE_SETUP
+@@ -22203,7 +22164,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 71:
  YY_RULE_SETUP
 -#line 956 "wcspih.l"
-+#line 953 "wcspih.l"
++#line 920 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.radesys;
-@@ -22214,7 +22211,7 @@ YY_RULE_SETUP
+@@ -22214,7 +22175,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 72:
  YY_RULE_SETUP
 -#line 964 "wcspih.l"
-+#line 961 "wcspih.l"
++#line 928 "wcspih.l"
  {
  	  if (relax & WCSHDR_RADECSYS) {
  	    valtype = STRING;
-@@ -22236,7 +22233,7 @@ YY_RULE_SETUP
+@@ -22236,7 +22197,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 73:
  YY_RULE_SETUP
 -#line 983 "wcspih.l"
-+#line 980 "wcspih.l"
++#line 947 "wcspih.l"
  {
  	  sscanf(yytext, "EPOCH%c", &a);
  	
-@@ -22265,7 +22262,7 @@ YY_RULE_SETUP
+@@ -22265,7 +22226,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 74:
  YY_RULE_SETUP
 -#line 1009 "wcspih.l"
-+#line 1006 "wcspih.l"
++#line 973 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.equinox);
-@@ -22276,7 +22273,7 @@ YY_RULE_SETUP
+@@ -22276,7 +22237,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 75:
  YY_RULE_SETUP
 -#line 1017 "wcspih.l"
-+#line 1014 "wcspih.l"
++#line 981 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.specsys;
-@@ -22287,7 +22284,7 @@ YY_RULE_SETUP
+@@ -22287,7 +22248,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 76:
  YY_RULE_SETUP
 -#line 1025 "wcspih.l"
-+#line 1022 "wcspih.l"
++#line 989 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.ssysobs;
-@@ -22298,7 +22295,7 @@ YY_RULE_SETUP
+@@ -22298,7 +22259,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 77:
  YY_RULE_SETUP
 -#line 1033 "wcspih.l"
-+#line 1030 "wcspih.l"
++#line 997 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.velosys);
-@@ -22309,7 +22306,7 @@ YY_RULE_SETUP
+@@ -22309,7 +22270,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 78:
  YY_RULE_SETUP
 -#line 1041 "wcspih.l"
-+#line 1038 "wcspih.l"
++#line 1005 "wcspih.l"
  {
  	  if (relax & WCSHDR_VSOURCE) {
  	    valtype = FLOAT;
-@@ -22332,7 +22329,7 @@ YY_RULE_SETUP
+@@ -22332,7 +22293,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 79:
  YY_RULE_SETUP
 -#line 1061 "wcspih.l"
-+#line 1058 "wcspih.l"
++#line 1025 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.zsource);
-@@ -22343,7 +22340,7 @@ YY_RULE_SETUP
+@@ -22343,7 +22304,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 80:
  YY_RULE_SETUP
 -#line 1069 "wcspih.l"
-+#line 1066 "wcspih.l"
++#line 1033 "wcspih.l"
  {
  	  valtype = STRING;
  	  vptr    = wcstem.ssyssrc;
-@@ -22354,7 +22351,7 @@ YY_RULE_SETUP
+@@ -22354,7 +22315,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 81:
  YY_RULE_SETUP
 -#line 1077 "wcspih.l"
-+#line 1074 "wcspih.l"
++#line 1041 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  vptr    = &(wcstem.velangl);
-@@ -22365,7 +22362,7 @@ YY_RULE_SETUP
+@@ -22365,7 +22326,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 82:
  YY_RULE_SETUP
 -#line 1085 "wcspih.l"
-+#line 1082 "wcspih.l"
++#line 1049 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  auxprm  = 1;
-@@ -22377,7 +22374,7 @@ YY_RULE_SETUP
+@@ -22377,7 +22338,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 83:
  YY_RULE_SETUP
 -#line 1094 "wcspih.l"
-+#line 1091 "wcspih.l"
++#line 1058 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  auxprm  = 1;
-@@ -22389,7 +22386,7 @@ YY_RULE_SETUP
+@@ -22389,7 +22350,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 84:
  YY_RULE_SETUP
 -#line 1103 "wcspih.l"
-+#line 1100 "wcspih.l"
++#line 1067 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  auxprm  = 1;
-@@ -22401,7 +22398,7 @@ YY_RULE_SETUP
+@@ -22401,7 +22362,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 85:
  YY_RULE_SETUP
 -#line 1112 "wcspih.l"
-+#line 1109 "wcspih.l"
++#line 1076 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  auxprm  = 1;
-@@ -22412,10 +22409,10 @@ YY_RULE_SETUP
+@@ -22412,10 +22373,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 86:
 -#line 1122 "wcspih.l"
-+#line 1119 "wcspih.l"
++#line 1086 "wcspih.l"
  case 87:
  YY_RULE_SETUP
 -#line 1122 "wcspih.l"
-+#line 1119 "wcspih.l"
++#line 1086 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  auxprm  = 1;
-@@ -22427,7 +22424,7 @@ YY_RULE_SETUP
+@@ -22427,7 +22388,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 88:
  YY_RULE_SETUP
 -#line 1131 "wcspih.l"
-+#line 1128 "wcspih.l"
++#line 1095 "wcspih.l"
  {
  	  valtype = STRING;
  	  distype = PRIOR;
-@@ -22439,7 +22436,7 @@ YY_RULE_SETUP
+@@ -22439,7 +22400,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 89:
  YY_RULE_SETUP
 -#line 1140 "wcspih.l"
-+#line 1137 "wcspih.l"
++#line 1104 "wcspih.l"
  {
  	  valtype = STRING;
  	  distype = SEQUENT;
-@@ -22451,7 +22448,7 @@ YY_RULE_SETUP
+@@ -22451,7 +22412,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 90:
  YY_RULE_SETUP
 -#line 1149 "wcspih.l"
-+#line 1146 "wcspih.l"
++#line 1113 "wcspih.l"
  {
  	  valtype = RECORD;
  	  distype = PRIOR;
-@@ -22464,7 +22461,7 @@ YY_RULE_SETUP
+@@ -22464,7 +22425,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 91:
  YY_RULE_SETUP
 -#line 1159 "wcspih.l"
-+#line 1156 "wcspih.l"
++#line 1123 "wcspih.l"
  {
  	  valtype = RECORD;
  	  distype = SEQUENT;
-@@ -22477,7 +22474,7 @@ YY_RULE_SETUP
+@@ -22477,7 +22438,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 92:
  YY_RULE_SETUP
 -#line 1169 "wcspih.l"
-+#line 1166 "wcspih.l"
++#line 1133 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  distype = PRIOR;
-@@ -22489,7 +22486,7 @@ YY_RULE_SETUP
+@@ -22489,7 +22450,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 93:
  YY_RULE_SETUP
 -#line 1178 "wcspih.l"
-+#line 1175 "wcspih.l"
++#line 1142 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  distype = SEQUENT;
-@@ -22501,7 +22498,7 @@ YY_RULE_SETUP
+@@ -22501,7 +22462,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 94:
  YY_RULE_SETUP
 -#line 1187 "wcspih.l"
-+#line 1184 "wcspih.l"
++#line 1151 "wcspih.l"
  {
  	  valtype = FLOAT;
  	  distype = PRIOR;
-@@ -22513,9 +22510,9 @@ YY_RULE_SETUP
+@@ -22513,9 +22474,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 95:
  YY_RULE_SETUP
 -#line 1196 "wcspih.l"
-+#line 1193 "wcspih.l"
++#line 1160 "wcspih.l"
  {
 -	  /* SIP: axis 1 polynomial degree (not stored). */
 +	  // SIP: axis 1 polynomial degree (not stored).
  	  valtype = INTEGER;
  	  distype = PRIOR;
  	  vptr    = 0x0;
-@@ -22529,9 +22526,9 @@ YY_RULE_SETUP
+@@ -22529,9 +22490,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 96:
  YY_RULE_SETUP
 -#line 1209 "wcspih.l"
-+#line 1206 "wcspih.l"
++#line 1173 "wcspih.l"
  {
 -	  /* SIP: axis 2 polynomial degree (not stored). */
 +	  // SIP: axis 2 polynomial degree (not stored).
  	  valtype = INTEGER;
  	  distype = PRIOR;
  	  vptr    = 0x0;
-@@ -22545,9 +22542,9 @@ YY_RULE_SETUP
+@@ -22545,9 +22506,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 97:
  YY_RULE_SETUP
 -#line 1222 "wcspih.l"
-+#line 1219 "wcspih.l"
++#line 1186 "wcspih.l"
  {
 -	  /* SIP: axis 1 inverse polynomial degree (not stored). */
 +	  // SIP: axis 1 inverse polynomial degree (not stored).
  	  valtype = INTEGER;
  	  distype = PRIOR;
  	  vptr    = 0x0;
-@@ -22561,9 +22558,9 @@ YY_RULE_SETUP
+@@ -22561,9 +22522,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 98:
  YY_RULE_SETUP
 -#line 1235 "wcspih.l"
-+#line 1232 "wcspih.l"
++#line 1199 "wcspih.l"
  {
 -	  /* SIP: axis 2 inverse polynomial degree (not stored). */
 +	  // SIP: axis 2 inverse polynomial degree (not stored).
  	  valtype = INTEGER;
  	  distype = PRIOR;
  	  vptr    = 0x0;
-@@ -22577,9 +22574,9 @@ YY_RULE_SETUP
+@@ -22577,9 +22538,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 99:
  YY_RULE_SETUP
 -#line 1248 "wcspih.l"
-+#line 1245 "wcspih.l"
++#line 1212 "wcspih.l"
  {
 -	  /* SIP: axis 1 maximum distortion. */
 +	  // SIP: axis 1 maximum distortion.
  	  valtype = FLOAT;
  	  distype = PRIOR;
  	  vptr    = &(distem.maxdis);
-@@ -22593,9 +22590,9 @@ YY_RULE_SETUP
+@@ -22593,9 +22554,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 100:
  YY_RULE_SETUP
 -#line 1261 "wcspih.l"
-+#line 1258 "wcspih.l"
++#line 1225 "wcspih.l"
  {
 -	  /* SIP: axis 2 maximum distortion. */
 +	  // SIP: axis 2 maximum distortion.
  	  valtype = FLOAT;
  	  distype = PRIOR;
  	  vptr    = &(distem.maxdis);
-@@ -22609,9 +22606,9 @@ YY_RULE_SETUP
+@@ -22609,9 +22570,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 101:
  YY_RULE_SETUP
 -#line 1274 "wcspih.l"
-+#line 1271 "wcspih.l"
++#line 1238 "wcspih.l"
  {
 -	  /* SIP: axis 1 polynomial coefficient. */
 +	  // SIP: axis 1 polynomial coefficient.
  	  i = 1;
  	  sipflag = 2;
  	
-@@ -22621,9 +22618,9 @@ YY_RULE_SETUP
+@@ -22621,9 +22582,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 102:
  YY_RULE_SETUP
 -#line 1283 "wcspih.l"
-+#line 1280 "wcspih.l"
++#line 1247 "wcspih.l"
  {
 -	  /* SIP: axis 2 polynomial coefficient. */
 +	  // SIP: axis 2 polynomial coefficient.
  	  i = 2;
  	  sipflag = 2;
  	
-@@ -22633,9 +22630,9 @@ YY_RULE_SETUP
+@@ -22633,9 +22594,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 103:
  YY_RULE_SETUP
 -#line 1292 "wcspih.l"
-+#line 1289 "wcspih.l"
++#line 1256 "wcspih.l"
  {
 -	  /* SIP: axis 1 inverse polynomial coefficient. */
 +	  // SIP: axis 1 inverse polynomial coefficient.
  	  i = 1;
  	  sipflag = 3;
  	
-@@ -22645,9 +22642,9 @@ YY_RULE_SETUP
+@@ -22645,9 +22606,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 104:
  YY_RULE_SETUP
 -#line 1301 "wcspih.l"
-+#line 1298 "wcspih.l"
++#line 1265 "wcspih.l"
  {
 -	  /* SIP: axis 2 inverse polynomial coefficient. */
 +	  // SIP: axis 2 inverse polynomial coefficient.
  	  i = 2;
  	  sipflag = 3;
  	
-@@ -22657,9 +22654,9 @@ YY_RULE_SETUP
+@@ -22657,9 +22618,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 105:
  YY_RULE_SETUP
 -#line 1310 "wcspih.l"
-+#line 1307 "wcspih.l"
++#line 1274 "wcspih.l"
  {
 -	  /* DSS: LLH corner pixel coordinate 1. */
 +	  // DSS: LLH corner pixel coordinate 1.
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp;
-@@ -22672,9 +22669,9 @@ YY_RULE_SETUP
+@@ -22672,9 +22633,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 106:
  YY_RULE_SETUP
 -#line 1322 "wcspih.l"
-+#line 1319 "wcspih.l"
++#line 1286 "wcspih.l"
  {
 -	  /* DSS: LLH corner pixel coordinate 2. */
 +	  // DSS: LLH corner pixel coordinate 2.
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+1;
-@@ -22687,9 +22684,9 @@ YY_RULE_SETUP
+@@ -22687,9 +22648,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 107:
  YY_RULE_SETUP
 -#line 1334 "wcspih.l"
-+#line 1331 "wcspih.l"
++#line 1298 "wcspih.l"
  {
 -	  /* DSS: plate centre x-coordinate in micron. */
 +	  // DSS: plate centre x-coordinate in micron.
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+2;
-@@ -22702,9 +22699,9 @@ YY_RULE_SETUP
+@@ -22702,9 +22663,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 108:
  YY_RULE_SETUP
 -#line 1346 "wcspih.l"
-+#line 1343 "wcspih.l"
++#line 1310 "wcspih.l"
  {
 -	  /* DSS: plate centre y-coordinate in micron. */
 +	  // DSS: plate centre y-coordinate in micron.
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+3;
-@@ -22717,9 +22714,9 @@ YY_RULE_SETUP
+@@ -22717,9 +22678,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 109:
  YY_RULE_SETUP
 -#line 1358 "wcspih.l"
-+#line 1355 "wcspih.l"
++#line 1322 "wcspih.l"
  {
 -	  /* DSS: pixel x-dimension in micron. */
 +	  // DSS: pixel x-dimension in micron.
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+4;
-@@ -22732,9 +22729,9 @@ YY_RULE_SETUP
+@@ -22732,9 +22693,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 110:
  YY_RULE_SETUP
 -#line 1370 "wcspih.l"
-+#line 1367 "wcspih.l"
++#line 1334 "wcspih.l"
  {
 -	  /* DSS: pixel y-dimension in micron. */
 +	  // DSS: pixel y-dimension in micron.
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+5;
-@@ -22747,9 +22744,9 @@ YY_RULE_SETUP
+@@ -22747,9 +22708,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 111:
  YY_RULE_SETUP
 -#line 1382 "wcspih.l"
-+#line 1379 "wcspih.l"
++#line 1346 "wcspih.l"
  {
 -	  /* DSS: plate centre, right ascension - hours. */
 +	  // DSS: plate centre, right ascension - hours.
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+6;
-@@ -22762,9 +22759,9 @@ YY_RULE_SETUP
+@@ -22762,9 +22723,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 112:
  YY_RULE_SETUP
 -#line 1394 "wcspih.l"
-+#line 1391 "wcspih.l"
++#line 1358 "wcspih.l"
  {
 -	  /* DSS: plate centre, right ascension - minutes. */
 +	  // DSS: plate centre, right ascension - minutes.
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+7;
-@@ -22777,9 +22774,9 @@ YY_RULE_SETUP
+@@ -22777,9 +22738,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 113:
  YY_RULE_SETUP
 -#line 1406 "wcspih.l"
-+#line 1403 "wcspih.l"
++#line 1370 "wcspih.l"
  {
 -	  /* DSS: plate centre, right ascension - seconds. */
 +	  // DSS: plate centre, right ascension - seconds.
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+8;
-@@ -22792,9 +22789,9 @@ YY_RULE_SETUP
+@@ -22792,9 +22753,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 114:
  YY_RULE_SETUP
 -#line 1418 "wcspih.l"
-+#line 1415 "wcspih.l"
++#line 1382 "wcspih.l"
  {
 -	  /* DSS: plate centre, declination - sign. */
 +	  // DSS: plate centre, declination - sign.
  	  valtype = STRING;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+9;
-@@ -22807,9 +22804,9 @@ YY_RULE_SETUP
+@@ -22807,9 +22768,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 115:
  YY_RULE_SETUP
 -#line 1430 "wcspih.l"
-+#line 1427 "wcspih.l"
++#line 1394 "wcspih.l"
  {
 -	  /* DSS: plate centre, declination - degrees. */
 +	  // DSS: plate centre, declination - degrees.
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+10;
-@@ -22822,9 +22819,9 @@ YY_RULE_SETUP
+@@ -22822,9 +22783,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 116:
  YY_RULE_SETUP
 -#line 1442 "wcspih.l"
-+#line 1439 "wcspih.l"
++#line 1406 "wcspih.l"
  {
 -	  /* DSS: plate centre, declination - arcmin. */
 +	  // DSS: plate centre, declination - arcmin.
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+11;
-@@ -22837,9 +22834,9 @@ YY_RULE_SETUP
+@@ -22837,9 +22798,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 117:
  YY_RULE_SETUP
 -#line 1454 "wcspih.l"
-+#line 1451 "wcspih.l"
++#line 1418 "wcspih.l"
  {
 -	  /* DSS: plate centre, declination - arcsec. */
 +	  // DSS: plate centre, declination - arcsec.
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+12;
-@@ -22852,9 +22849,9 @@ YY_RULE_SETUP
+@@ -22852,9 +22813,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 118:
  YY_RULE_SETUP
 -#line 1466 "wcspih.l"
-+#line 1463 "wcspih.l"
++#line 1430 "wcspih.l"
  {
 -	  /* DSS: plate identification (insufficient to trigger DSS). */
 +	  // DSS: plate identification (insufficient to trigger DSS).
  	  valtype = STRING;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+13;
-@@ -22867,9 +22864,9 @@ YY_RULE_SETUP
+@@ -22867,9 +22828,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 119:
  YY_RULE_SETUP
 -#line 1478 "wcspih.l"
-+#line 1475 "wcspih.l"
++#line 1442 "wcspih.l"
  {
 -	  /* DSS: axis 1 polynomial coefficient. */
 +	  // DSS: axis 1 polynomial coefficient.
  	  i = 1;
  	  dssflag = 3;
  	
-@@ -22879,9 +22876,9 @@ YY_RULE_SETUP
+@@ -22879,9 +22840,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 120:
  YY_RULE_SETUP
 -#line 1487 "wcspih.l"
-+#line 1484 "wcspih.l"
++#line 1451 "wcspih.l"
  {
 -	  /* DSS: axis 2 polynomial coefficient. */
 +	  // DSS: axis 2 polynomial coefficient.
  	  i = 2;
  	  dssflag = 3;
  	
-@@ -22891,9 +22888,9 @@ YY_RULE_SETUP
+@@ -22891,9 +22852,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 121:
  YY_RULE_SETUP
 -#line 1496 "wcspih.l"
-+#line 1493 "wcspih.l"
++#line 1460 "wcspih.l"
  {
 -	  /* TNX or ZPX: string-encoded data array. */
 +	  // TNX or ZPX: string-encoded data array.
  	  sscanf(yytext, "WAT%d_%d", &i, &m);
  	  if (watn < m) watn = m;
  	  watflag = 1;
-@@ -22911,7 +22908,7 @@ YY_RULE_SETUP
+@@ -22911,10 +22872,10 @@ YY_RULE_SETUP
  	YY_BREAK
  case 122:
  YY_RULE_SETUP
 -#line 1513 "wcspih.l"
-+#line 1510 "wcspih.l"
++#line 1477 "wcspih.l"
  {
- 	  if (wcspih_nkeyrec) {
- 	    wcspih_nkeyrec = 0;
-@@ -22924,161 +22921,161 @@ YY_RULE_SETUP
+-	  if (wcspih_nkeyrec) {
+-	    wcspih_nkeyrec = 0;
++	  if (yyextra->nkeyrec) {
++	    yyextra->nkeyrec = 0;
+ 	    errmsg = "keyrecords following the END keyrecord were ignored";
+ 	    BEGIN(ERROR);
+ 	  } else {
+@@ -22924,161 +22885,161 @@ YY_RULE_SETUP
  	YY_BREAK
  case 123:
  YY_RULE_SETUP
 -#line 1523 "wcspih.l"
-+#line 1520 "wcspih.l"
++#line 1487 "wcspih.l"
  {
  	  BEGIN(DISCARD);
  	}
  	YY_BREAK
  case 124:
 -#line 1528 "wcspih.l"
-+#line 1525 "wcspih.l"
++#line 1492 "wcspih.l"
  case 125:
 -#line 1529 "wcspih.l"
-+#line 1526 "wcspih.l"
++#line 1493 "wcspih.l"
  case 126:
 -#line 1530 "wcspih.l"
-+#line 1527 "wcspih.l"
++#line 1494 "wcspih.l"
  case 127:
  YY_RULE_SETUP
 -#line 1530 "wcspih.l"
-+#line 1527 "wcspih.l"
++#line 1494 "wcspih.l"
  {
  	  sscanf(yytext, "%d%c", &i, &a);
  	  BEGIN(VALUE);
@@ -9368,26 +10591,26 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	YY_BREAK
  case 128:
 -#line 1536 "wcspih.l"
-+#line 1533 "wcspih.l"
++#line 1500 "wcspih.l"
  case 129:
 -#line 1537 "wcspih.l"
-+#line 1534 "wcspih.l"
++#line 1501 "wcspih.l"
  case 130:
 -#line 1538 "wcspih.l"
-+#line 1535 "wcspih.l"
++#line 1502 "wcspih.l"
  case 131:
 -#line 1539 "wcspih.l"
-+#line 1536 "wcspih.l"
++#line 1503 "wcspih.l"
  case 132:
 -#line 1540 "wcspih.l"
-+#line 1537 "wcspih.l"
++#line 1504 "wcspih.l"
  case 133:
 -#line 1541 "wcspih.l"
-+#line 1538 "wcspih.l"
++#line 1505 "wcspih.l"
  case 134:
  YY_RULE_SETUP
 -#line 1541 "wcspih.l"
-+#line 1538 "wcspih.l"
++#line 1505 "wcspih.l"
  {
  	  if (relax & WCSHDR_reject) {
 -	    /* Violates the basic FITS standard. */
@@ -9405,32 +10628,32 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	YY_BREAK
  case 135:
 -#line 1555 "wcspih.l"
-+#line 1552 "wcspih.l"
++#line 1519 "wcspih.l"
  case 136:
 -#line 1556 "wcspih.l"
-+#line 1553 "wcspih.l"
++#line 1520 "wcspih.l"
  case 137:
 -#line 1557 "wcspih.l"
-+#line 1554 "wcspih.l"
++#line 1521 "wcspih.l"
  case 138:
 -#line 1558 "wcspih.l"
-+#line 1555 "wcspih.l"
++#line 1522 "wcspih.l"
  case 139:
 -#line 1559 "wcspih.l"
-+#line 1556 "wcspih.l"
++#line 1523 "wcspih.l"
  case 140:
 -#line 1560 "wcspih.l"
-+#line 1557 "wcspih.l"
++#line 1524 "wcspih.l"
  case 141:
 -#line 1561 "wcspih.l"
-+#line 1558 "wcspih.l"
++#line 1525 "wcspih.l"
  case 142:
 -#line 1562 "wcspih.l"
-+#line 1559 "wcspih.l"
++#line 1526 "wcspih.l"
  case 143:
  YY_RULE_SETUP
 -#line 1562 "wcspih.l"
-+#line 1559 "wcspih.l"
++#line 1526 "wcspih.l"
  {
 -	  /* Anything that has fallen through to this point must contain */
 -	  /* an invalid axis number. */
@@ -9443,7 +10666,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  case 144:
  YY_RULE_SETUP
 -#line 1569 "wcspih.l"
-+#line 1566 "wcspih.l"
++#line 1533 "wcspih.l"
  {
 -	  /* Let it go. */
 +	  // Let it go.
@@ -9453,7 +10676,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  case 145:
  YY_RULE_SETUP
 -#line 1574 "wcspih.l"
-+#line 1571 "wcspih.l"
++#line 1538 "wcspih.l"
  {
  	  if (relax & WCSHDR_reject) {
 -	    /* Looks too much like a FITS WCS keyword not to flag it. */
@@ -9472,17 +10695,17 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	YY_BREAK
  case 146:
 -#line 1589 "wcspih.l"
-+#line 1586 "wcspih.l"
++#line 1553 "wcspih.l"
  case 147:
 -#line 1590 "wcspih.l"
-+#line 1587 "wcspih.l"
++#line 1554 "wcspih.l"
  case 148:
 -#line 1591 "wcspih.l"
-+#line 1588 "wcspih.l"
++#line 1555 "wcspih.l"
  case 149:
  YY_RULE_SETUP
 -#line 1591 "wcspih.l"
-+#line 1588 "wcspih.l"
++#line 1555 "wcspih.l"
  {
  	  sscanf(yytext, "%d_%d%c", &i, &j, &a);
  	  BEGIN(VALUE);
@@ -9490,72 +10713,72 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	YY_BREAK
  case 150:
 -#line 1598 "wcspih.l"
-+#line 1595 "wcspih.l"
++#line 1562 "wcspih.l"
  case 151:
 -#line 1599 "wcspih.l"
-+#line 1596 "wcspih.l"
++#line 1563 "wcspih.l"
  case 152:
 -#line 1600 "wcspih.l"
-+#line 1597 "wcspih.l"
++#line 1564 "wcspih.l"
  case 153:
 -#line 1601 "wcspih.l"
-+#line 1598 "wcspih.l"
++#line 1565 "wcspih.l"
  case 154:
 -#line 1602 "wcspih.l"
-+#line 1599 "wcspih.l"
++#line 1566 "wcspih.l"
  case 155:
 -#line 1603 "wcspih.l"
-+#line 1600 "wcspih.l"
++#line 1567 "wcspih.l"
  case 156:
 -#line 1604 "wcspih.l"
-+#line 1601 "wcspih.l"
++#line 1568 "wcspih.l"
  case 157:
 -#line 1605 "wcspih.l"
-+#line 1602 "wcspih.l"
++#line 1569 "wcspih.l"
  case 158:
 -#line 1606 "wcspih.l"
-+#line 1603 "wcspih.l"
++#line 1570 "wcspih.l"
  case 159:
 -#line 1607 "wcspih.l"
-+#line 1604 "wcspih.l"
++#line 1571 "wcspih.l"
  case 160:
 -#line 1608 "wcspih.l"
-+#line 1605 "wcspih.l"
++#line 1572 "wcspih.l"
  case 161:
 -#line 1609 "wcspih.l"
-+#line 1606 "wcspih.l"
++#line 1573 "wcspih.l"
  case 162:
 -#line 1610 "wcspih.l"
-+#line 1607 "wcspih.l"
++#line 1574 "wcspih.l"
  case 163:
 -#line 1611 "wcspih.l"
-+#line 1608 "wcspih.l"
++#line 1575 "wcspih.l"
  case 164:
 -#line 1612 "wcspih.l"
-+#line 1609 "wcspih.l"
++#line 1576 "wcspih.l"
  case 165:
 -#line 1613 "wcspih.l"
-+#line 1610 "wcspih.l"
++#line 1577 "wcspih.l"
  case 166:
 -#line 1614 "wcspih.l"
-+#line 1611 "wcspih.l"
++#line 1578 "wcspih.l"
  case 167:
 -#line 1615 "wcspih.l"
-+#line 1612 "wcspih.l"
++#line 1579 "wcspih.l"
  case 168:
 -#line 1616 "wcspih.l"
-+#line 1613 "wcspih.l"
++#line 1580 "wcspih.l"
  case 169:
 -#line 1617 "wcspih.l"
-+#line 1614 "wcspih.l"
++#line 1581 "wcspih.l"
  case 170:
  YY_RULE_SETUP
 -#line 1617 "wcspih.l"
-+#line 1614 "wcspih.l"
++#line 1581 "wcspih.l"
  {
  	  if (((altlin == 1) && (relax & WCSHDR_PC0i_0ja)) ||
  	      ((altlin == 2) && (relax & WCSHDR_CD0i_0ja))) {
-@@ -23091,60 +23088,60 @@ YY_RULE_SETUP
+@@ -23091,60 +23052,60 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -9567,35 +10790,35 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	YY_BREAK
  case 171:
 -#line 1635 "wcspih.l"
-+#line 1632 "wcspih.l"
++#line 1599 "wcspih.l"
  case 172:
 -#line 1636 "wcspih.l"
-+#line 1633 "wcspih.l"
++#line 1600 "wcspih.l"
  case 173:
 -#line 1637 "wcspih.l"
-+#line 1634 "wcspih.l"
++#line 1601 "wcspih.l"
  case 174:
 -#line 1638 "wcspih.l"
-+#line 1635 "wcspih.l"
++#line 1602 "wcspih.l"
  case 175:
 -#line 1639 "wcspih.l"
-+#line 1636 "wcspih.l"
++#line 1603 "wcspih.l"
  case 176:
 -#line 1640 "wcspih.l"
-+#line 1637 "wcspih.l"
++#line 1604 "wcspih.l"
  case 177:
 -#line 1641 "wcspih.l"
-+#line 1638 "wcspih.l"
++#line 1605 "wcspih.l"
  case 178:
 -#line 1642 "wcspih.l"
-+#line 1639 "wcspih.l"
++#line 1606 "wcspih.l"
  case 179:
 -#line 1643 "wcspih.l"
-+#line 1640 "wcspih.l"
++#line 1607 "wcspih.l"
  case 180:
  YY_RULE_SETUP
 -#line 1643 "wcspih.l"
-+#line 1640 "wcspih.l"
++#line 1607 "wcspih.l"
  {
 -	  /* Anything that has fallen through to this point must contain */
 -	  /* an invalid axis number. */
@@ -9607,51 +10830,51 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	YY_BREAK
  case 181:
 -#line 1651 "wcspih.l"
-+#line 1648 "wcspih.l"
++#line 1615 "wcspih.l"
  case 182:
 -#line 1652 "wcspih.l"
-+#line 1649 "wcspih.l"
++#line 1616 "wcspih.l"
  case 183:
 -#line 1653 "wcspih.l"
-+#line 1650 "wcspih.l"
++#line 1617 "wcspih.l"
  case 184:
 -#line 1654 "wcspih.l"
-+#line 1651 "wcspih.l"
++#line 1618 "wcspih.l"
  case 185:
 -#line 1655 "wcspih.l"
-+#line 1652 "wcspih.l"
++#line 1619 "wcspih.l"
  case 186:
 -#line 1656 "wcspih.l"
-+#line 1653 "wcspih.l"
++#line 1620 "wcspih.l"
  case 187:
 -#line 1657 "wcspih.l"
-+#line 1654 "wcspih.l"
++#line 1621 "wcspih.l"
  case 188:
 -#line 1658 "wcspih.l"
-+#line 1655 "wcspih.l"
++#line 1622 "wcspih.l"
  case 189:
 -#line 1659 "wcspih.l"
-+#line 1656 "wcspih.l"
++#line 1623 "wcspih.l"
  case 190:
  YY_RULE_SETUP
 -#line 1659 "wcspih.l"
-+#line 1656 "wcspih.l"
++#line 1623 "wcspih.l"
  {
  	  errmsg = errtxt;
  	  sprintf(errmsg, "%s keyword must use an underscore, not a dash",
-@@ -23154,9 +23151,9 @@ YY_RULE_SETUP
+@@ -23154,9 +23115,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 191:
  YY_RULE_SETUP
 -#line 1666 "wcspih.l"
-+#line 1663 "wcspih.l"
++#line 1630 "wcspih.l"
  {
 -	  /* This covers the defunct forms CD00i00j and PC00i00j. */
 +	  // This covers the defunct forms CD00i00j and PC00i00j.
  	  if (((altlin == 1) && (relax & WCSHDR_PC00i00j)) ||
  	      ((altlin == 2) && (relax & WCSHDR_CD00i00j))) {
  	    sscanf(yytext, "%3d%3d", &i, &j);
-@@ -23171,23 +23168,23 @@ YY_RULE_SETUP
+@@ -23171,23 +23132,23 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -9664,27 +10887,27 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  case 192:
  YY_RULE_SETUP
 -#line 1687 "wcspih.l"
-+#line 1684 "wcspih.l"
++#line 1651 "wcspih.l"
  {
  	  BEGIN(DISCARD);
  	}
  	YY_BREAK
  case 193:
 -#line 1692 "wcspih.l"
-+#line 1689 "wcspih.l"
++#line 1656 "wcspih.l"
  case 194:
  YY_RULE_SETUP
 -#line 1692 "wcspih.l"
-+#line 1689 "wcspih.l"
++#line 1656 "wcspih.l"
  {
  	  if (YY_START == CCCCCCCa) {
  	    sscanf(yytext, "%c", &a);
-@@ -23201,78 +23198,78 @@ YY_RULE_SETUP
+@@ -23201,78 +23162,78 @@ YY_RULE_SETUP
  	YY_BREAK
  case 195:
  YY_RULE_SETUP
 -#line 1703 "wcspih.l"
-+#line 1700 "wcspih.l"
++#line 1667 "wcspih.l"
  {
  	  if (relax & WCSHDR_reject) {
 -	    /* Looks too much like a FITS WCS keyword not to flag it. */
@@ -9703,17 +10926,17 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	YY_BREAK
  case 196:
 -#line 1718 "wcspih.l"
-+#line 1715 "wcspih.l"
++#line 1682 "wcspih.l"
  case 197:
 -#line 1719 "wcspih.l"
-+#line 1716 "wcspih.l"
++#line 1683 "wcspih.l"
  case 198:
 -#line 1720 "wcspih.l"
-+#line 1717 "wcspih.l"
++#line 1684 "wcspih.l"
  case 199:
  YY_RULE_SETUP
 -#line 1720 "wcspih.l"
-+#line 1717 "wcspih.l"
++#line 1684 "wcspih.l"
  {
  	  sscanf(yytext, "%d_%d%c", &i, &m, &a);
  	  BEGIN(VALUE);
@@ -9721,72 +10944,72 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	YY_BREAK
  case 200:
 -#line 1726 "wcspih.l"
-+#line 1723 "wcspih.l"
++#line 1690 "wcspih.l"
  case 201:
 -#line 1727 "wcspih.l"
-+#line 1724 "wcspih.l"
++#line 1691 "wcspih.l"
  case 202:
 -#line 1728 "wcspih.l"
-+#line 1725 "wcspih.l"
++#line 1692 "wcspih.l"
  case 203:
 -#line 1729 "wcspih.l"
-+#line 1726 "wcspih.l"
++#line 1693 "wcspih.l"
  case 204:
 -#line 1730 "wcspih.l"
-+#line 1727 "wcspih.l"
++#line 1694 "wcspih.l"
  case 205:
 -#line 1731 "wcspih.l"
-+#line 1728 "wcspih.l"
++#line 1695 "wcspih.l"
  case 206:
 -#line 1732 "wcspih.l"
-+#line 1729 "wcspih.l"
++#line 1696 "wcspih.l"
  case 207:
 -#line 1733 "wcspih.l"
-+#line 1730 "wcspih.l"
++#line 1697 "wcspih.l"
  case 208:
 -#line 1734 "wcspih.l"
-+#line 1731 "wcspih.l"
++#line 1698 "wcspih.l"
  case 209:
 -#line 1735 "wcspih.l"
-+#line 1732 "wcspih.l"
++#line 1699 "wcspih.l"
  case 210:
 -#line 1736 "wcspih.l"
-+#line 1733 "wcspih.l"
++#line 1700 "wcspih.l"
  case 211:
 -#line 1737 "wcspih.l"
-+#line 1734 "wcspih.l"
++#line 1701 "wcspih.l"
  case 212:
 -#line 1738 "wcspih.l"
-+#line 1735 "wcspih.l"
++#line 1702 "wcspih.l"
  case 213:
 -#line 1739 "wcspih.l"
-+#line 1736 "wcspih.l"
++#line 1703 "wcspih.l"
  case 214:
 -#line 1740 "wcspih.l"
-+#line 1737 "wcspih.l"
++#line 1704 "wcspih.l"
  case 215:
 -#line 1741 "wcspih.l"
-+#line 1738 "wcspih.l"
++#line 1705 "wcspih.l"
  case 216:
 -#line 1742 "wcspih.l"
-+#line 1739 "wcspih.l"
++#line 1706 "wcspih.l"
  case 217:
 -#line 1743 "wcspih.l"
-+#line 1740 "wcspih.l"
++#line 1707 "wcspih.l"
  case 218:
 -#line 1744 "wcspih.l"
-+#line 1741 "wcspih.l"
++#line 1708 "wcspih.l"
  case 219:
 -#line 1745 "wcspih.l"
-+#line 1742 "wcspih.l"
++#line 1709 "wcspih.l"
  case 220:
  YY_RULE_SETUP
 -#line 1745 "wcspih.l"
-+#line 1742 "wcspih.l"
++#line 1709 "wcspih.l"
  {
  	  if (((valtype == FLOAT)  && (relax & WCSHDR_PV0i_0ma)) ||
  	      ((valtype == STRING) && (relax & WCSHDR_PS0i_0ma))) {
-@@ -23285,60 +23282,60 @@ YY_RULE_SETUP
+@@ -23285,60 +23246,60 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -9798,35 +11021,35 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	YY_BREAK
  case 221:
 -#line 1763 "wcspih.l"
-+#line 1760 "wcspih.l"
++#line 1727 "wcspih.l"
  case 222:
 -#line 1764 "wcspih.l"
-+#line 1761 "wcspih.l"
++#line 1728 "wcspih.l"
  case 223:
 -#line 1765 "wcspih.l"
-+#line 1762 "wcspih.l"
++#line 1729 "wcspih.l"
  case 224:
 -#line 1766 "wcspih.l"
-+#line 1763 "wcspih.l"
++#line 1730 "wcspih.l"
  case 225:
 -#line 1767 "wcspih.l"
-+#line 1764 "wcspih.l"
++#line 1731 "wcspih.l"
  case 226:
 -#line 1768 "wcspih.l"
-+#line 1765 "wcspih.l"
++#line 1732 "wcspih.l"
  case 227:
 -#line 1769 "wcspih.l"
-+#line 1766 "wcspih.l"
++#line 1733 "wcspih.l"
  case 228:
 -#line 1770 "wcspih.l"
-+#line 1767 "wcspih.l"
++#line 1734 "wcspih.l"
  case 229:
 -#line 1771 "wcspih.l"
-+#line 1768 "wcspih.l"
++#line 1735 "wcspih.l"
  case 230:
  YY_RULE_SETUP
 -#line 1771 "wcspih.l"
-+#line 1768 "wcspih.l"
++#line 1735 "wcspih.l"
  {
 -	  /* Anything that has fallen through to this point must contain */
 -	  /* an invalid axis number. */
@@ -9838,62 +11061,62 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	YY_BREAK
  case 231:
 -#line 1779 "wcspih.l"
-+#line 1776 "wcspih.l"
++#line 1743 "wcspih.l"
  case 232:
 -#line 1780 "wcspih.l"
-+#line 1777 "wcspih.l"
++#line 1744 "wcspih.l"
  case 233:
 -#line 1781 "wcspih.l"
-+#line 1778 "wcspih.l"
++#line 1745 "wcspih.l"
  case 234:
 -#line 1782 "wcspih.l"
-+#line 1779 "wcspih.l"
++#line 1746 "wcspih.l"
  case 235:
 -#line 1783 "wcspih.l"
-+#line 1780 "wcspih.l"
++#line 1747 "wcspih.l"
  case 236:
 -#line 1784 "wcspih.l"
-+#line 1781 "wcspih.l"
++#line 1748 "wcspih.l"
  case 237:
 -#line 1785 "wcspih.l"
-+#line 1782 "wcspih.l"
++#line 1749 "wcspih.l"
  case 238:
 -#line 1786 "wcspih.l"
-+#line 1783 "wcspih.l"
++#line 1750 "wcspih.l"
  case 239:
 -#line 1787 "wcspih.l"
-+#line 1784 "wcspih.l"
++#line 1751 "wcspih.l"
  case 240:
  YY_RULE_SETUP
 -#line 1787 "wcspih.l"
-+#line 1784 "wcspih.l"
++#line 1751 "wcspih.l"
  {
  	  errmsg = errtxt;
  	  sprintf(errmsg, "%s keyword must use an underscore, not a dash",
-@@ -23348,18 +23345,18 @@ YY_RULE_SETUP
+@@ -23348,18 +23309,18 @@ YY_RULE_SETUP
  	YY_BREAK
  case 241:
  YY_RULE_SETUP
 -#line 1794 "wcspih.l"
-+#line 1791 "wcspih.l"
++#line 1758 "wcspih.l"
  {
  	  BEGIN(DISCARD);
  	}
  	YY_BREAK
  case 242:
 -#line 1799 "wcspih.l"
-+#line 1796 "wcspih.l"
++#line 1763 "wcspih.l"
  case 243:
 -#line 1800 "wcspih.l"
-+#line 1797 "wcspih.l"
++#line 1764 "wcspih.l"
  case 244:
  YY_RULE_SETUP
 -#line 1800 "wcspih.l"
-+#line 1797 "wcspih.l"
++#line 1764 "wcspih.l"
  {
  	  a = ' ';
  	  sscanf(yytext, "%d%c", &i, &a);
-@@ -23377,14 +23374,14 @@ YY_RULE_SETUP
+@@ -23377,14 +23338,14 @@ YY_RULE_SETUP
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -9906,97 +11129,97 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  case 245:
  YY_RULE_SETUP
 -#line 1822 "wcspih.l"
-+#line 1819 "wcspih.l"
++#line 1786 "wcspih.l"
  {
  	  yyless(0);
  	  BEGIN(CCCCCia);
-@@ -23392,7 +23389,7 @@ YY_RULE_SETUP
+@@ -23392,7 +23353,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 246:
  YY_RULE_SETUP
 -#line 1827 "wcspih.l"
-+#line 1824 "wcspih.l"
++#line 1791 "wcspih.l"
  {
  	  if (relax & WCSHDR_PROJPn) {
  	    sscanf(yytext, "%d", &m);
-@@ -23410,10 +23407,10 @@ YY_RULE_SETUP
+@@ -23410,10 +23371,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 247:
 -#line 1844 "wcspih.l"
-+#line 1841 "wcspih.l"
++#line 1808 "wcspih.l"
  case 248:
  YY_RULE_SETUP
 -#line 1844 "wcspih.l"
-+#line 1841 "wcspih.l"
++#line 1808 "wcspih.l"
  {
  	  if (relax & (WCSHDR_PROJPn | WCSHDR_reject)) {
  	    errmsg = "invalid PROJPn keyword";
-@@ -23426,18 +23423,18 @@ YY_RULE_SETUP
+@@ -23426,18 +23387,18 @@ YY_RULE_SETUP
  	YY_BREAK
  case 249:
  YY_RULE_SETUP
 -#line 1854 "wcspih.l"
-+#line 1851 "wcspih.l"
++#line 1818 "wcspih.l"
  {
  	  BEGIN(DISCARD);
  	}
  	YY_BREAK
  case 250:
 -#line 1859 "wcspih.l"
-+#line 1856 "wcspih.l"
++#line 1823 "wcspih.l"
  case 251:
  YY_RULE_SETUP
 -#line 1859 "wcspih.l"
-+#line 1856 "wcspih.l"
++#line 1823 "wcspih.l"
  {
 -	  /* SIP keywords. */
 +	  // SIP keywords.
  	  valtype = FLOAT;
  	  distype = PRIOR;
  	  vptr    = &(distem.dp);
-@@ -23451,21 +23448,21 @@ YY_RULE_SETUP
+@@ -23451,21 +23412,21 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 252:
 -#line 1874 "wcspih.l"
-+#line 1871 "wcspih.l"
++#line 1838 "wcspih.l"
  case 253:
  YY_RULE_SETUP
 -#line 1874 "wcspih.l"
-+#line 1871 "wcspih.l"
++#line 1838 "wcspih.l"
  {
  	  BEGIN(DISCARD);
  	}
  	YY_BREAK
  case 254:
 -#line 1879 "wcspih.l"
-+#line 1876 "wcspih.l"
++#line 1843 "wcspih.l"
  case 255:
  YY_RULE_SETUP
 -#line 1879 "wcspih.l"
-+#line 1876 "wcspih.l"
++#line 1843 "wcspih.l"
  {
 -	  /* DSS keywords. */
 +	  // DSS keywords.
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = &(distem.dp);
-@@ -23480,7 +23477,7 @@ YY_RULE_SETUP
+@@ -23480,7 +23441,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 256:
  YY_RULE_SETUP
 -#line 1893 "wcspih.l"
-+#line 1890 "wcspih.l"
++#line 1857 "wcspih.l"
  {
  	  BEGIN(DISCARD);
  	}
-@@ -23488,11 +23485,11 @@ YY_RULE_SETUP
+@@ -23488,11 +23449,11 @@ YY_RULE_SETUP
  case 257:
  /* rule 257 can match eol */
  YY_RULE_SETUP
 -#line 1897 "wcspih.l"
-+#line 1894 "wcspih.l"
++#line 1861 "wcspih.l"
  {
 -	  /* Special handling for this iconic DSS keyword. */
 +	  // Special handling for this iconic DSS keyword.
@@ -10006,12 +11229,12 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	    sscanf(yytext, "= '%s", strtmp);
  	    dbltmp = strcmp(strtmp, "-") ? 1.0 : -1.0;
  	  }
-@@ -23502,16 +23499,16 @@ YY_RULE_SETUP
+@@ -23502,16 +23463,16 @@ YY_RULE_SETUP
  	YY_BREAK
  case 258:
  YY_RULE_SETUP
 -#line 1908 "wcspih.l"
-+#line 1905 "wcspih.l"
++#line 1872 "wcspih.l"
  {
  	  BEGIN(DISCARD);
  	}
@@ -10019,14 +11242,14 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  case 259:
  YY_RULE_SETUP
 -#line 1912 "wcspih.l"
-+#line 1909 "wcspih.l"
++#line 1876 "wcspih.l"
  {
 -	  /* Do checks on i, j & m. */
 +	  // Do checks on i, j & m.
  	  if (99 < i || 99 < j || 99 < m) {
  	    if (relax & WCSHDR_reject) {
  	      if (99 < i || 99 < j) {
-@@ -23522,7 +23519,7 @@ YY_RULE_SETUP
+@@ -23522,7 +23483,7 @@ YY_RULE_SETUP
  	      BEGIN(ERROR);
  	
  	    } else {
@@ -10035,21 +11258,21 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	      BEGIN(DISCARD);
  	    }
  	
-@@ -23548,7 +23545,7 @@ YY_RULE_SETUP
+@@ -23548,7 +23509,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 260:
  YY_RULE_SETUP
 -#line 1948 "wcspih.l"
-+#line 1945 "wcspih.l"
++#line 1912 "wcspih.l"
  {
  	  errmsg = "invalid KEYWORD = VALUE syntax";
  	  BEGIN(ERROR);
-@@ -23556,13 +23553,13 @@ YY_RULE_SETUP
+@@ -23556,13 +23517,13 @@ YY_RULE_SETUP
  	YY_BREAK
  case 261:
  YY_RULE_SETUP
 -#line 1953 "wcspih.l"
-+#line 1950 "wcspih.l"
++#line 1917 "wcspih.l"
  {
  	  if (ipass == 1) {
  	    BEGIN(COMMENT);
@@ -10060,21 +11283,21 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	    sscanf(yytext, "%d", &inttmp);
  	
  	    BEGIN(COMMENT);
-@@ -23571,7 +23568,7 @@ YY_RULE_SETUP
+@@ -23571,7 +23532,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 262:
  YY_RULE_SETUP
 -#line 1965 "wcspih.l"
-+#line 1962 "wcspih.l"
++#line 1929 "wcspih.l"
  {
  	  errmsg = "an integer value was expected";
  	  BEGIN(ERROR);
-@@ -23579,13 +23576,13 @@ YY_RULE_SETUP
+@@ -23579,13 +23540,13 @@ YY_RULE_SETUP
  	YY_BREAK
  case 263:
  YY_RULE_SETUP
 -#line 1970 "wcspih.l"
-+#line 1967 "wcspih.l"
++#line 1934 "wcspih.l"
  {
  	  if (ipass == 1) {
  	    BEGIN(COMMENT);
@@ -10085,21 +11308,21 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	    wcsutil_str2double(yytext, &dbltmp);
  
  	    if (chekval && chekval(dbltmp)) {
-@@ -23599,7 +23596,7 @@ YY_RULE_SETUP
+@@ -23599,7 +23560,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 264:
  YY_RULE_SETUP
 -#line 1987 "wcspih.l"
-+#line 1984 "wcspih.l"
++#line 1951 "wcspih.l"
  {
  	  errmsg = "a floating-point value was expected";
  	  BEGIN(ERROR);
-@@ -23607,13 +23604,13 @@ YY_RULE_SETUP
+@@ -23607,13 +23568,13 @@ YY_RULE_SETUP
  	YY_BREAK
  case 265:
  YY_RULE_SETUP
 -#line 1992 "wcspih.l"
-+#line 1989 "wcspih.l"
++#line 1956 "wcspih.l"
  {
  	  if (ipass == 1) {
  	    BEGIN(COMMENT);
@@ -10110,21 +11333,21 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	    wcsutil_str2double2(yytext, dbl2tmp);
  	
  	    BEGIN(COMMENT);
-@@ -23622,7 +23619,7 @@ YY_RULE_SETUP
+@@ -23622,7 +23583,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 266:
  YY_RULE_SETUP
 -#line 2004 "wcspih.l"
-+#line 2001 "wcspih.l"
++#line 1968 "wcspih.l"
  {
  	  errmsg = "a floating-point value was expected";
  	  BEGIN(ERROR);
-@@ -23631,16 +23628,16 @@ YY_RULE_SETUP
+@@ -23631,18 +23592,18 @@ YY_RULE_SETUP
  case 267:
  /* rule 267 can match eol */
  YY_RULE_SETUP
 -#line 2009 "wcspih.l"
-+#line 2006 "wcspih.l"
++#line 1973 "wcspih.l"
  {
  	  if (ipass == 1) {
  	    BEGIN(COMMENT);
@@ -10135,61 +11358,65 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	    strcpy(strtmp, yytext+1);
  	
 -	    /* Squeeze out repeated quotes. */
+-	    ix = 0;
+-	    for (jx = 0; jx < 72; jx++) {
 +	    // Squeeze out repeated quotes.
- 	    ix = 0;
- 	    for (jx = 0; jx < 72; jx++) {
++	    int ix = 0;
++	    for (int jx = 0; jx < 72; jx++) {
  	      if (ix < jx) {
-@@ -23663,7 +23660,7 @@ YY_RULE_SETUP
+ 	        strtmp[ix] = strtmp[jx];
+ 	      }
+@@ -23663,7 +23624,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 268:
  YY_RULE_SETUP
 -#line 2038 "wcspih.l"
-+#line 2035 "wcspih.l"
++#line 2002 "wcspih.l"
  {
  	  errmsg = "a string value was expected";
  	  BEGIN(ERROR);
-@@ -23672,7 +23669,7 @@ YY_RULE_SETUP
+@@ -23672,7 +23633,7 @@ YY_RULE_SETUP
  case 269:
  /* rule 269 can match eol */
  YY_RULE_SETUP
 -#line 2043 "wcspih.l"
-+#line 2040 "wcspih.l"
++#line 2007 "wcspih.l"
  {
  	  if (ipass == 1) {
  	    BEGIN(COMMENT);
-@@ -23686,7 +23683,7 @@ YY_RULE_SETUP
+@@ -23686,7 +23647,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 270:
  YY_RULE_SETUP
 -#line 2054 "wcspih.l"
-+#line 2051 "wcspih.l"
++#line 2018 "wcspih.l"
  {
  	  errmsg = "a record was expected";
  	  BEGIN(ERROR);
-@@ -23694,7 +23691,7 @@ YY_RULE_SETUP
+@@ -23694,7 +23655,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 271:
  YY_RULE_SETUP
 -#line 2059 "wcspih.l"
-+#line 2056 "wcspih.l"
++#line 2023 "wcspih.l"
  {
  	  strcpy(strtmp, yytext);
  	  BEGIN(RECCOLON);
-@@ -23702,7 +23699,7 @@ YY_RULE_SETUP
+@@ -23702,7 +23663,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 272:
  YY_RULE_SETUP
 -#line 2064 "wcspih.l"
-+#line 2061 "wcspih.l"
++#line 2028 "wcspih.l"
  {
  	  errmsg = "invalid record field";
  	  BEGIN(ERROR);
-@@ -23710,14 +23707,14 @@ YY_RULE_SETUP
+@@ -23710,14 +23671,14 @@ YY_RULE_SETUP
  	YY_BREAK
  case 273:
  YY_RULE_SETUP
 -#line 2069 "wcspih.l"
-+#line 2066 "wcspih.l"
++#line 2033 "wcspih.l"
  {
  	  BEGIN(RECVALUE);
  	}
@@ -10197,52 +11424,52 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  case 274:
  YY_RULE_SETUP
 -#line 2073 "wcspih.l"
-+#line 2070 "wcspih.l"
++#line 2037 "wcspih.l"
  {
  	  errmsg = "invalid record syntax";
  	  BEGIN(ERROR);
-@@ -23725,7 +23722,7 @@ YY_RULE_SETUP
+@@ -23725,7 +23686,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 275:
  YY_RULE_SETUP
 -#line 2078 "wcspih.l"
-+#line 2075 "wcspih.l"
++#line 2042 "wcspih.l"
  {
  	  rectype = 0;
  	  sscanf(yytext, "%d", &inttmp);
-@@ -23734,7 +23731,7 @@ YY_RULE_SETUP
+@@ -23734,7 +23695,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 276:
  YY_RULE_SETUP
 -#line 2084 "wcspih.l"
-+#line 2081 "wcspih.l"
++#line 2048 "wcspih.l"
  {
  	  rectype = 1;
  	  wcsutil_str2double(yytext, &dbltmp);
-@@ -23743,7 +23740,7 @@ YY_RULE_SETUP
+@@ -23743,7 +23704,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 277:
  YY_RULE_SETUP
 -#line 2090 "wcspih.l"
-+#line 2087 "wcspih.l"
++#line 2054 "wcspih.l"
  {
  	  errmsg = "invalid record value";
  	  BEGIN(ERROR);
-@@ -23751,7 +23748,7 @@ YY_RULE_SETUP
+@@ -23751,7 +23712,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 278:
  YY_RULE_SETUP
 -#line 2095 "wcspih.l"
-+#line 2092 "wcspih.l"
++#line 2059 "wcspih.l"
  {
  	  BEGIN(COMMENT);
  	}
-@@ -23761,19 +23758,19 @@ case 279:
+@@ -23761,19 +23722,19 @@ case 279:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 2099 "wcspih.l"
-+#line 2096 "wcspih.l"
++#line 2063 "wcspih.l"
  {
  	  if (ipass == 1) {
 -	    /* Do first-pass bookkeeping. */
@@ -10252,31 +11479,36 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	
  	  } else if (*wcs) {
 -	    /* Store the value now that the keyrecord has been validated. */
-+	    // Store the value now that the keyrecord has been validated.
- 	    gotone = 0;
- 	    for (ialt = 0; ialt < *nwcs; ialt++) {
+-	    gotone = 0;
+-	    for (ialt = 0; ialt < *nwcs; ialt++) {
 -	      /* The loop here is for keywords that apply */
 -	      /* to every alternate; these have a == 0. */
++	    // Store the value now that the keyrecord has been validated.
++	    int gotone = 0;
++	    for (int ialt = 0; ialt < *nwcs; ialt++) {
 +	      // The loop here is for keywords that apply
 +	      // to every alternate; these have a == 0.
  	      if (a >= 'A') {
  	        ialt = alts[a-'A'+1];
  	        if (ialt < 0) break;
-@@ -23782,11 +23779,11 @@ YY_RULE_SETUP
+@@ -23782,11 +23743,12 @@ YY_RULE_SETUP
  	
  	      if (vptr) {
  	        if (sipflag) {
 -	          /* Translate a SIP keyword into DPja. */
+-	          disp = (*wcs)->lin.dispre;
+-	          ipx = (disp->ndp)++;
 +	          // Translate a SIP keyword into DPja.
- 	          disp = (*wcs)->lin.dispre;
- 	          ipx = (disp->ndp)++;
++	          struct disprm *disp = (*wcs)->lin.dispre;
++	          int ipx = (disp->ndp)++;
  	
 -	          /* SIP doesn't have alternates. */
 +	          // SIP doesn't have alternates.
++		  char keyword[16];
  	          sprintf(keyword, "DP%d", i);
  	          sprintf(strtmp, "SIP.%s.%d_%d", (sipflag==2)?"FWD":"REV",
  	                  p, q);
-@@ -23797,27 +23794,27 @@ YY_RULE_SETUP
+@@ -23797,27 +23759,28 @@ YY_RULE_SETUP
  	          }
  	
  	        } else if (dssflag) {
@@ -10296,11 +11528,14 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
 -	            /* Translate a DSS keyword into DQia. */
 +	            // Translate a DSS keyword into DQia.
  	            if (m <= 13 || dbltmp != 0.0) {
- 	              disp = (*wcs)->lin.disseq;
- 	              ipx = (disp->ndp)++;
+-	              disp = (*wcs)->lin.disseq;
+-	              ipx = (disp->ndp)++;
++	              struct disprm *disp = (*wcs)->lin.disseq;
++	              int ipx = (disp->ndp)++;
  	
 -	              /* DSS doesn't have alternates. */
 +	              // DSS doesn't have alternates.
++		      char keyword[16];
  	              sprintf(keyword, "DQ%d", i);
  	              sprintf(strtmp, "DSS.AMD.%d", m);
  	              dpfill(disp->dp+ipx, keyword, strtmp, i, 1, 0, dbltmp);
@@ -10310,7 +11545,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	              if (m <= 3) {
  	                dsstmp[13+(i-1)*3+m] = dbltmp;
  	              }
-@@ -23825,32 +23822,32 @@ YY_RULE_SETUP
+@@ -23825,32 +23788,35 @@ YY_RULE_SETUP
  	          }
  	
  	        } else if (watflag) {
@@ -10320,12 +11555,17 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	
  	        } else {
 -	          /* An "ordinary" keyword. */
+-	          wcsp = *wcs + ialt;
 +	          // An "ordinary" keyword.
- 	          wcsp = *wcs + ialt;
++	          struct wcsprm *wcsp = *wcs + ialt;
++		  struct disprm *disp;
++	          void *wptr;
++	          ptrdiff_t voff;
  	          if (auxprm) {
 -	            /* Additional auxiliary parameter. */
+-	            auxp = wcsp->aux;
 +	            // Additional auxiliary parameter.
- 	            auxp = wcsp->aux;
++	            struct auxprm *auxp = wcsp->aux;
  	            voff = (char *)vptr - (char *)(&auxtem);
  	            wptr = (void *)((char *)auxp + voff);
  	
@@ -10350,16 +11590,19 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	            voff = (char *)vptr - (char *)(&wcstem);
  	            wptr = (void *)((char *)wcsp + voff);
  	          }
-@@ -23859,7 +23856,7 @@ YY_RULE_SETUP
+@@ -23859,9 +23825,9 @@ YY_RULE_SETUP
  	            *((int *)wptr) = inttmp;
  	
  	          } else if (valtype == FLOAT) {
 -	            /* Apply keyword parameterization. */
 +	            // Apply keyword parameterization.
  	            if (npptr == npv) {
- 	              ipx = (wcsp->npv)++;
+-	              ipx = (wcsp->npv)++;
++	              int ipx = (wcsp->npv)++;
  	              wcsp->pv[ipx].i = i;
-@@ -23880,14 +23877,14 @@ YY_RULE_SETUP
+ 	              wcsp->pv[ipx].m = m;
+ 	              wptr = &(wcsp->pv[ipx].value);
+@@ -23880,14 +23846,14 @@ YY_RULE_SETUP
  	              *((double *)wptr) = dbltmp;
  	            }
  	
@@ -10376,57 +11619,85 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	            if (special) {
  	              special(wptr, dbl2tmp);
  	            } else {
-@@ -23896,7 +23893,7 @@ YY_RULE_SETUP
+@@ -23896,9 +23862,9 @@ YY_RULE_SETUP
  	            }
  	
  	          } else if (valtype == STRING) {
 -	            /* Apply keyword parameterization. */
 +	            // Apply keyword parameterization.
  	            if (npptr == nps) {
- 	              ipx = (wcsp->nps)++;
+-	              ipx = (wcsp->nps)++;
++	              int ipx = (wcsp->nps)++;
  	              wcsp->ps[ipx].i = i;
-@@ -23961,7 +23958,7 @@ case 280:
+ 	              wcsp->ps[ipx].m = m;
+ 	              wptr = wcsp->ps[ipx].value;
+@@ -23911,12 +23877,13 @@ YY_RULE_SETUP
+ 	              wptr = *((char (**)[72])wptr) + (i - 1);
+ 	            }
+ 	
+-	            cptr = (char *)wptr;
++	            char *cptr = (char *)wptr;
+ 	            strcpy(cptr, strtmp);
+ 	
+ 	          } else if (valtype == RECORD) {
+-	            ipx = (disp->ndp)++;
++	            int ipx = (disp->ndp)++;
+ 	
++		    char keyword[16];
+ 	            if (a == ' ') {
+ 	              sprintf(keyword, "%.2s%d", keyname, i);
+ 	            } else {
+@@ -23937,7 +23904,7 @@ YY_RULE_SETUP
+ 	      if (ctrl == 4) {
+ 	        if (distran || dssflag) {
+ 	          wcsfprintf(stderr, "%.80s\n  Accepted (%d) as a "
+-	            "recognised WCS convention.\n", keyrec, nvalid);
++	            "recognized WCS convention.\n", keyrec, nvalid);
+ 	        } else {
+ 	          wcsfprintf(stderr, "%.80s\n  Accepted (%d) as a "
+ 	            "valid WCS keyrecord.\n", keyrec, nvalid);
+@@ -23961,7 +23928,7 @@ case 280:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 2293 "wcspih.l"
-+#line 2290 "wcspih.l"
++#line 2263 "wcspih.l"
  {
  	  errmsg = "invalid keyvalue";
  	  BEGIN(ERROR);
-@@ -23972,7 +23969,7 @@ case 281:
+@@ -23972,7 +23939,7 @@ case 281:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 2298 "wcspih.l"
-+#line 2295 "wcspih.l"
++#line 2268 "wcspih.l"
  {
  	  errmsg = "invalid keyvalue";
  	  BEGIN(ERROR);
-@@ -23983,7 +23980,7 @@ case 282:
+@@ -23983,7 +23950,7 @@ case 282:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 2303 "wcspih.l"
-+#line 2300 "wcspih.l"
++#line 2273 "wcspih.l"
  {
  	  errmsg = "invalid keyvalue or malformed keycomment";
  	  BEGIN(ERROR);
-@@ -23994,7 +23991,7 @@ case 283:
+@@ -23994,7 +23961,7 @@ case 283:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 2308 "wcspih.l"
-+#line 2305 "wcspih.l"
++#line 2278 "wcspih.l"
  {
  	  errmsg = "malformed keycomment";
  	  BEGIN(ERROR);
-@@ -24005,11 +24002,11 @@ case 284:
+@@ -24005,11 +23972,11 @@ case 284:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 2313 "wcspih.l"
-+#line 2310 "wcspih.l"
++#line 2283 "wcspih.l"
  {
  	  if (ipass == npass) {
  	    if (ctrl < 0) {
@@ -10435,12 +11706,12 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	      keep = keyrec;
  	
  	    } else if (2 < ctrl) {
-@@ -24026,13 +24023,13 @@ case 285:
+@@ -24026,13 +23993,13 @@ case 285:
  yyg->yy_c_buf_p = yy_cp -= 1;
  YY_DO_BEFORE_ACTION; /* set up yytext again */
  YY_RULE_SETUP
 -#line 2328 "wcspih.l"
-+#line 2325 "wcspih.l"
++#line 2298 "wcspih.l"
  {
  	  if (ipass == npass) {
  	    (*nreject)++;
@@ -10451,16 +11722,16 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	      keep = keyrec;
  	    }
  	
-@@ -24047,7 +24044,7 @@ YY_RULE_SETUP
+@@ -24047,7 +24014,7 @@ YY_RULE_SETUP
  case 286:
  /* rule 286 can match eol */
  YY_RULE_SETUP
 -#line 2345 "wcspih.l"
-+#line 2342 "wcspih.l"
++#line 2315 "wcspih.l"
  {
  	  if (ipass == npass && keep) {
  	    if (hptr < keep) {
-@@ -24058,7 +24055,7 @@ YY_RULE_SETUP
+@@ -24058,7 +24025,7 @@ YY_RULE_SETUP
  	
  	  naux += auxprm;
  	
@@ -10469,52 +11740,105 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  	  i = j = 0;
  	  m = 0;
  	  a = ' ';
-@@ -24109,9 +24106,9 @@ case YY_STATE_EOF(COMMENT):
+@@ -24109,9 +24076,10 @@ case YY_STATE_EOF(COMMENT):
  case YY_STATE_EOF(DISCARD):
  case YY_STATE_EOF(ERROR):
  case YY_STATE_EOF(FLUSH):
 -#line 2379 "wcspih.l"
-+#line 2376 "wcspih.l"
++#line 2349 "wcspih.l"
  {
 -	  /* End-of-input. */
 +	  // End-of-input.
++	  int status;
  	  if (ipass == 1) {
  	    if ((status = wcspih_init1(naxis, alts, dpq, npv, nps, ndp, ndq,
  	                               naux, distran, nwcs, wcs)) ||
-@@ -24185,10 +24182,10 @@ case YY_STATE_EOF(FLUSH):
+@@ -24136,8 +24104,8 @@ case YY_STATE_EOF(FLUSH):
+ 	  }
+ 	
+ 	  if (ipass++ < npass) {
+-	    wcspih_hdr = header;
+-	    wcspih_nkeyrec = nkeyrec;
++	    yyextra->hdr = header;
++	    yyextra->nkeyrec = nkeyrec;
+ 	    keyrec = header;
+ 	    *nreject = 0;
+ 	
+@@ -24185,10 +24153,10 @@ case YY_STATE_EOF(FLUSH):
  	YY_BREAK
  case 287:
  YY_RULE_SETUP
 -#line 2452 "wcspih.l"
-+#line 2449 "wcspih.l"
++#line 2423 "wcspih.l"
  ECHO;
  	YY_BREAK
 -#line 24192 "wcspih.c"
-+#line 24189 "wcspih.c"
++#line 24160 "wcspih.c"
  
  	case YY_END_OF_BUFFER:
  		{
-@@ -25353,7 +25350,7 @@ void yyfree (void * ptr , yyscan_t yysca
+@@ -25353,7 +25321,36 @@ void yyfree (void * ptr , yyscan_t yysca
  
  #define YYTABLES_NAME "yytables"
  
 -#line 2452 "wcspih.l"
-+#line 2449 "wcspih.l"
++#line 2423 "wcspih.l"
++
++
++/*----------------------------------------------------------------------------
++* External interface to the scanner.
++*---------------------------------------------------------------------------*/
++
++int wcspih(
++  char *header,
++  int nkeyrec,
++  int relax,
++  int ctrl,
++  int *nreject,
++  int *nwcs,
++  struct wcsprm **wcs)
++
++{
++  // Function prototypes.
++  int yylex_init_extra(YY_EXTRA_TYPE extra, yyscan_t *yyscanner);
++  int yylex_destroy(yyscan_t yyscanner);
++
++  struct wcspih_extra extra;
++  yyscan_t yyscanner;
++  yylex_init_extra(&extra, &yyscanner);
++  int status = wcspih_scanner(header, nkeyrec, relax, ctrl, nreject, nwcs,
++                              wcs, yyscanner);
++  yylex_destroy(yyscanner);
++
++  return status;
++}
  
  
  /*----------------------------------------------------------------------------
-@@ -25373,8 +25370,8 @@ void wcspih_pass1(
+@@ -25373,26 +25370,24 @@ void wcspih_pass1(
    int *npptr)
  
  {
 -  /* On the first pass alts[] is used to determine the number of axes */
 -  /* for each of the 27 possible alternate coordinate descriptions.   */
+-  int ialt, *ip;
+-
 +  // On the first pass alts[] is used to determine the number of axes
 +  // for each of the 27 possible alternate coordinate descriptions.
-   int ialt, *ip;
- 
    if (a == 0) {
-@@ -25392,7 +25389,7 @@ void wcspih_pass1(
+     return;
+   }
+ 
+-  ialt = 0;
++  int ialt = 0;
+   if (a != ' ') {
+     ialt = a - 'A' + 1;
+   }
+ 
+-  ip = alts + ialt;
++  int *ip = alts + ialt;
+ 
+   if (*ip < naxis) {
      *ip = naxis;
    }
  
@@ -10523,7 +11847,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
    if (*ip < i) {
      *ip = i;
    }
-@@ -25401,10 +25398,10 @@ void wcspih_pass1(
+@@ -25401,10 +25396,10 @@ void wcspih_pass1(
      *ip = j;
    }
  
@@ -10536,17 +11860,24 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
    if (npptr) {
      npptr[ialt]++;
    }
-@@ -25434,37 +25431,37 @@ int wcspih_init1(
-   struct wcsprm *wcsp;
-   struct disprm *dis;
+@@ -25430,115 +25425,115 @@ int wcspih_init1(
+   struct wcsprm **wcs)
+ 
+ {
+-  int ialt, defaults, ndis, ndpmax, npsmax, npvmax, status = 0;
+-  struct wcsprm *wcsp;
+-  struct disprm *dis;
++  int status = 0;
  
 -  /* Find the number of coordinate descriptions. */
 +  // Find the number of coordinate descriptions.
    *nwcs = 0;
-   for (ialt = 0; ialt < 27; ialt++) {
+-  for (ialt = 0; ialt < 27; ialt++) {
++  for (int ialt = 0; ialt < 27; ialt++) {
      if (alts[ialt]) (*nwcs)++;
    }
  
++  int defaults;
    if ((defaults = !(*nwcs) && naxis)) {
 -    /* NAXIS is non-zero but there were no WCS keywords with an alternate
 -       version code; create a default WCS with blank alternate version. */
@@ -10563,7 +11894,8 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
        return WCSHDRERR_MEMORY;
      }
  
-     ndis = 0;
+-    ndis = 0;
++    int ndis = 0;
      if (distran == SIP) {
 -      /* DPja.NAXES and DPja.OFFSET.j to be added for SIP (see below and
 -         wcspih_final()). */
@@ -10578,11 +11910,20 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
      }
  
 -    /* Initialize each wcsprm struct. */
+-    wcsp = *wcs;
 +    // Initialize each wcsprm struct.
-     wcsp = *wcs;
++    struct wcsprm *wcsp = *wcs;
      *nwcs = 0;
-     for (ialt = 0; ialt < 27; ialt++) {
-@@ -25477,30 +25474,30 @@ int wcspih_init1(
+-    for (ialt = 0; ialt < 27; ialt++) {
++    for (int ialt = 0; ialt < 27; ialt++) {
+       if (alts[ialt]) {
+         wcsp->flag = -1;
+-        npvmax = npv[ialt];
+-        npsmax = nps[ialt];
++        int npvmax = npv[ialt];
++        int npsmax = nps[ialt];
+         if ((status = wcsinit(1, alts[ialt], wcsp, npvmax, npsmax, -1))) {
+           wcsvfree(nwcs, wcs);
            break;
          }
  
@@ -10608,26 +11949,39 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  
 -        /* Any distortions present? */
 +        // Any distortions present?
++        struct disprm *disp;
          if (dpq[ialt] & 1) {
-           if ((dis = calloc(1, sizeof(struct disprm))) == 0x0) {
+-          if ((dis = calloc(1, sizeof(struct disprm))) == 0x0) {
++          if ((disp = calloc(1, sizeof(struct disprm))) == 0x0) {
              return WCSHDRERR_MEMORY;
            }
  
 -          /* Attach it to linprm.  Also inits it. */
 +          // Attach it to linprm.  Also inits it.
            ndis++;
-           ndpmax = ndp[ialt];
-           dis->flag = -1;
-@@ -25512,33 +25509,33 @@ int wcspih_init1(
+-          ndpmax = ndp[ialt];
+-          dis->flag = -1;
+-          lindist(1, &(wcsp->lin), dis, ndpmax);
++          int ndpmax = ndp[ialt];
++          disp->flag = -1;
++          lindist(1, &(wcsp->lin), disp, ndpmax);
+         }
+ 
+         if (dpq[ialt] & 2) {
+-          if ((dis = calloc(1, sizeof(struct disprm))) == 0x0) {
++          if ((disp = calloc(1, sizeof(struct disprm))) == 0x0) {
              return WCSHDRERR_MEMORY;
            }
  
 -          /* Attach it to linprm.  Also inits it. */
 +          // Attach it to linprm.  Also inits it.
            ndis++;
-           ndpmax = ndq[ialt];
-           dis->flag = -1;
-           lindist(2, &(wcsp->lin), dis, ndpmax);
+-          ndpmax = ndq[ialt];
+-          dis->flag = -1;
+-          lindist(2, &(wcsp->lin), dis, ndpmax);
++          int ndpmax = ndq[ialt];
++          disp->flag = -1;
++          lindist(2, &(wcsp->lin), disp, ndpmax);
          }
  
 -        /* On the second pass alts[] indexes the array of wcsprm structs. */
@@ -10659,7 +12013,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
        (*wcs)->lin.dispre->ndp = 6;
        dpfill((*wcs)->lin.dispre->dp,   "DP1", "NAXES",  0, 0, 2, 0.0);
        dpfill((*wcs)->lin.dispre->dp+3, "DP2", "NAXES",  0, 0, 2, 0.0);
-@@ -25547,7 +25544,7 @@ int wcspih_init1(
+@@ -25547,7 +25542,7 @@ int wcspih_init1(
        strcpy((*wcs)->lin.disseq->dtype[0], "DSS");
        strcpy((*wcs)->lin.disseq->dtype[1], "DSS");
  
@@ -10668,7 +12022,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
        (*wcs)->lin.disseq->ndp = 2;
        dpfill((*wcs)->lin.disseq->dp,   "DQ1", "NAXES",  0, 0, 2, 0.0);
        dpfill((*wcs)->lin.disseq->dp+1, "DQ2", "NAXES",  0, 0, 2, 0.0);
-@@ -25565,7 +25562,7 @@ int wcspih_init1(
+@@ -25565,7 +25560,7 @@ int wcspih_init1(
  int wcspih_jdref(double *mjdref, const double *jdref)
  
  {
@@ -10677,7 +12031,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
    if (undefined(mjdref[0] && undefined(mjdref[1]))) {
      mjdref[0] = jdref[0] - 2400000.0;
      mjdref[1] = jdref[1] - 0.5;
-@@ -25582,7 +25579,7 @@ int wcspih_jdref(double *mjdref, const d
+@@ -25582,7 +25577,7 @@ int wcspih_jdref(double *mjdref, const d
  int wcspih_jdrefi(double *mjdref, const double *jdrefi)
  
  {
@@ -10686,7 +12040,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
    if (undefined(mjdref[0])) {
      mjdref[0] = *jdrefi - 2400000.5;
    }
-@@ -25594,7 +25591,7 @@ int wcspih_jdrefi(double *mjdref, const
+@@ -25594,7 +25589,7 @@ int wcspih_jdrefi(double *mjdref, const
  int wcspih_jdreff(double *mjdref, const double *jdreff)
  
  {
@@ -10695,7 +12049,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
    if (undefined(mjdref[1])) {
      mjdref[1] = *jdreff;
    }
-@@ -25610,7 +25607,7 @@ int wcspih_jdreff(double *mjdref, const
+@@ -25610,7 +25605,7 @@ int wcspih_jdreff(double *mjdref, const
  int wcspih_epoch(double *equinox, const double *epoch)
  
  {
@@ -10704,24 +12058,39 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
    if (undefined(*equinox)) {
      *equinox = *epoch;
    }
-@@ -25628,9 +25625,9 @@ int wcspih_vsource(double *zsource, cons
+@@ -25626,12 +25621,12 @@ int wcspih_epoch(double *equinox, const
+ int wcspih_vsource(double *zsource, const double *vsource)
+ 
  {
-   double beta, c = 299792458.0;
+-  double beta, c = 299792458.0;
++  const double c = 299792458.0;
  
 -  /* If ZSOURCEa is currently undefined then set it from VSOURCEa. */
 +  // If ZSOURCEa is currently undefined then set it from VSOURCEa.
    if (undefined(*zsource)) {
 -    /* Convert relativistic Doppler velocity to redshift. */
+-    beta = *vsource/c;
 +    // Convert relativistic Doppler velocity to redshift.
-     beta = *vsource/c;
++    double beta = *vsource/c;
      *zsource = (1.0 + beta)/sqrt(1.0 - beta*beta) - 1.0;
    }
-@@ -25672,23 +25669,23 @@ int wcspih_final(
-   struct wcsprm *wcsp;
  
-   for (ialt = 0; ialt < *nwcs; ialt++) {
+@@ -25664,58 +25659,52 @@ int wcspih_final(
+   struct wcsprm **wcs)
+ 
+ {
+-  char   field[32], *wp, wpoly[12], wtype[8];
+-  int    i, ialt, idp, ipv, m, npv, n, nterms, omax, omin, status, wctrl[4];
+-  double A1, A2, A3, B1, B2, B3, CNPIX1, CNPIX2, *crval, Rx, Ry, S, wval,
+-         X0, Y0, Xc, Yc;
+-  struct disprm *disp;
+-  struct wcsprm *wcsp;
+-
+-  for (ialt = 0; ialt < *nwcs; ialt++) {
 -    /* Interpret -TAB header keywords. */
++  for (int ialt = 0; ialt < *nwcs; ialt++) {
 +    // Interpret -TAB header keywords.
++    int status;
      if ((status = wcstab(*wcs+ialt))) {
         wcsvfree(nwcs, wcs);
         return status;
@@ -10737,26 +12106,72 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
    }
  
 -  /* Translated distortion functions; apply only to the primary WCS. */
+-  wcsp = *wcs;
 +  // Translated distortion functions; apply only to the primary WCS.
-   wcsp = *wcs;
++  struct wcsprm *wcsp = *wcs;
    if (distran == SIP) {
 -    /* SIP doesn't have alternates, nor axis mapping. */
+-    disp = wcsp->lin.dispre;
 +    // SIP doesn't have alternates, nor axis mapping.
-     disp = wcsp->lin.dispre;
++    struct disprm *disp = wcsp->lin.dispre;
      dpfill(disp->dp+1, "DP1", "OFFSET.1",  0, 1, 0, wcsp->crpix[0]);
      dpfill(disp->dp+2, "DP1", "OFFSET.2",  0, 1, 0, wcsp->crpix[1]);
-@@ -25696,8 +25693,8 @@ int wcspih_final(
+     dpfill(disp->dp+4, "DP2", "OFFSET.1",  0, 1, 0, wcsp->crpix[0]);
      dpfill(disp->dp+5, "DP2", "OFFSET.2",  0, 1, 0, wcsp->crpix[1]);
  
    } else if (distran == DSS) {
 -    /* DSS doesn't have alternates, nor axis mapping.  This translation */
 -    /* follows Paper IV, Sect. 5.2 using the same variable names.       */
+-    CNPIX1 = dsstmp[0];
+-    CNPIX2 = dsstmp[1];
+-
+-    Xc = dsstmp[2]/1000.0;
+-    Yc = dsstmp[3]/1000.0;
+-    Rx = dsstmp[4]/1000.0;
+-    Ry = dsstmp[5]/1000.0;
+-
+-    A1 = dsstmp[14];
+-    A2 = dsstmp[15];
+-    A3 = dsstmp[16];
+-    B1 = dsstmp[17];
+-    B2 = dsstmp[18];
+-    B3 = dsstmp[19];
+-    S  = sqrt(fabs(A1*B1 - A2*B2));
 +    // DSS doesn't have alternates, nor axis mapping.  This translation
 +    // follows Paper IV, Sect. 5.2 using the same variable names.
-     CNPIX1 = dsstmp[0];
-     CNPIX2 = dsstmp[1];
++    double CNPIX1 = dsstmp[0];
++    double CNPIX2 = dsstmp[1];
++
++    double Xc = dsstmp[2]/1000.0;
++    double Yc = dsstmp[3]/1000.0;
++    double Rx = dsstmp[4]/1000.0;
++    double Ry = dsstmp[5]/1000.0;
++
++    double A1 = dsstmp[14];
++    double A2 = dsstmp[15];
++    double A3 = dsstmp[16];
++    double B1 = dsstmp[17];
++    double B2 = dsstmp[18];
++    double B3 = dsstmp[19];
++    double S  = sqrt(fabs(A1*B1 - A2*B2));
  
-@@ -25739,17 +25736,17 @@ int wcspih_final(
+-    X0 = (A2*B3 - A3*B1) / (A1*B1 - A2*B2);
+-    Y0 = (A3*B2 - A1*B3) / (A1*B1 - A2*B2);
++    double X0 = (A2*B3 - A3*B1) / (A1*B1 - A2*B2);
++    double Y0 = (A3*B2 - A1*B3) / (A1*B1 - A2*B2);
+ 
+     wcsp->crpix[0] = (Xc - X0)/Rx - (CNPIX1 - 0.5);
+     wcsp->crpix[1] = (Yc + Y0)/Ry - (CNPIX2 - 0.5);
+@@ -25729,7 +25718,7 @@ int wcspih_final(
+     wcsp->cdelt[0] = -S/3600.0;
+     wcsp->cdelt[1] =  S/3600.0;
+ 
+-    crval = wcsp->crval;
++    double *crval = wcsp->crval;
+     crval[0] = (dsstmp[6]  + (dsstmp[7]  + dsstmp[8] /60.0)/60.0)*15.0;
+     crval[1] =  dsstmp[10] + (dsstmp[11] + dsstmp[12]/60.0)/60.0;
+     if (dsstmp[9] == -1.0) crval[1] *= -1.0;
+@@ -25739,19 +25728,23 @@ int wcspih_final(
  
      sprintf(wcsp->wcsname, "DSS PLATEID %.4s", (char *)(dsstmp+13));
  
@@ -10769,15 +12184,23 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
  
    } else if (distran == WAT) {
 -    /* TNX and ZPX don't have alternates, nor axis mapping. */
+-    disp = wcsp->lin.disseq;
 +    // TNX and ZPX don't have alternates, nor axis mapping.
-     disp = wcsp->lin.disseq;
++    char *wp;
++    int  omax, omin, wctrl[4];
++    double wval;
++    struct disprm *disp = wcsp->lin.disseq;
  
 -    /* Disassemble the core dump stored in the WATi_m strings. */
+-    nterms = 0;
 +    // Disassemble the core dump stored in the WATi_m strings.
-     nterms = 0;
++    int i, nterms = 0;
      for (i = 0; i < 2; i++) {
++      char wtype[8];
        sscanf(wat[i], "wtype=%s", wtype);
-@@ -25759,22 +25756,22 @@ int wcspih_final(
+ 
+       if (strcmp(wtype, "tnx") == 0) {
+@@ -25759,22 +25752,23 @@ int wcspih_final(
        } else if (strcmp(wtype, "zpx") == 0) {
          strcpy(disp->dtype[i], "WAT-ZPX");
        } else {
@@ -10792,9 +12215,11 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
        if (i == 1 && strcmp(wtype, "zpx") == 0) {
 -        /* Take those on the second (latitude) axis ignoring the other. */
 -        /* First we have to count them and allocate space in wcsprm.    */
+-        wp  = wat[i];
 +        // Take those on the second (latitude) axis ignoring the other.
 +        // First we have to count them and allocate space in wcsprm.
-         wp  = wat[i];
++        wp = wat[i];
++	int npv;
          for (npv = 0; npv < 30; npv++) {
            if ((wp = strstr(wp, "projp")) == 0x0) break;
            wp += 5;
@@ -10805,16 +12230,22 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
          if (npv) {
            wcsp->npvmax += npv;
            wcsp->pv = realloc(wcsp->pv, wcsp->npvmax*sizeof(struct pvcard));
-@@ -25785,7 +25782,7 @@ int wcspih_final(
+@@ -25785,11 +25779,12 @@ int wcspih_final(
            wcsp->m_pv = wcsp->pv;
          }
  
 -        /* Copy the values. */
 +        // Copy the values.
          wp = wat[i];
-         for (ipv = wcsp->npv; ipv < wcsp->npvmax; ipv++) {
+-        for (ipv = wcsp->npv; ipv < wcsp->npvmax; ipv++) {
++        for (int ipv = wcsp->npv; ipv < wcsp->npvmax; ipv++) {
            if ((wp = strstr(wp, "projp")) == 0x0) break;
-@@ -25801,7 +25798,7 @@ int wcspih_final(
+ 
++          int m;
+           sscanf(wp, "projp%d=%lf", &m, &wval);
+           wcsp->pv[ipv].i = 2;
+           wcsp->pv[ipv].m = m;
+@@ -25801,13 +25796,13 @@ int wcspih_final(
          wcsp->npv += npv;
        }
  
@@ -10823,7 +12254,14 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
        if ((wp = strchr(wat[i], '"')) == 0x0) {
          return WCSHDRERR_PARSER;
        }
-@@ -25815,24 +25812,24 @@ int wcspih_final(
+       wp++;
+ 
+-      for (m = 0; m < 4; m++) {
++      for (int m = 0; m < 4; m++) {
+         sscanf(wp, "%d", wctrl+m);
+         if ((wp = strchr(wp, ' ')) == 0x0) {
+           return WCSHDRERR_PARSER;
+@@ -25815,24 +25810,24 @@ int wcspih_final(
          wp++;
        }
  
@@ -10853,13 +12291,14 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
      ndq[0] += 2*(1 + 1 + 4) + nterms;
  
      disp->ndpmax += ndq[0];
-@@ -25844,12 +25841,12 @@ int wcspih_final(
+@@ -25844,18 +25839,18 @@ int wcspih_final(
      disp->m_dp = disp->dp;
  
  
 -    /* Populate dpkeys. */
+-    idp = disp->ndp;
 +    // Populate dpkeys.
-     idp = disp->ndp;
++    int idp = disp->ndp;
      for (i = 0; i < 2; i++) {
        dpfill(disp->dp+(idp++), "DQ", "NAXES", i+1, 0, 2, 0.0);
  
@@ -10868,12 +12307,20 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
        if ((wp = strchr(wat[i], '"')) == 0x0) {
          return WCSHDRERR_PARSER;
        }
-@@ -25863,23 +25860,23 @@ int wcspih_final(
+       wp++;
+ 
+-      for (m = 0; m < 4; m++) {
++      for (int m = 0; m < 4; m++) {
+         sscanf(wp, "%d", wctrl+m);
+         if ((wp = strchr(wp, ' ')) == 0x0) {
+           return WCSHDRERR_PARSER;
+@@ -25863,24 +25858,26 @@ int wcspih_final(
          wp++;
        }
  
 -      /* Polynomial type. */
 +      // Polynomial type.
++      char wpoly[12];
        dpfill(disp->dp+(idp++), "DQ", "WAT.POLY", i+1, 0, wctrl[0], 0.0);
        if (wctrl[0] == 1) {
 -        /* Chebyshev polynomial. */
@@ -10894,23 +12341,30 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcspih.c
        }
  
 -      /* Read the scaling parameters. */
+-      for (m = 0; m < 4; m++) {
 +      // Read the scaling parameters.
-       for (m = 0; m < 4; m++) {
++      char field[40];
++      for (int m = 0; m < 4; m++) {
          sscanf(wp, "%lf", &wval);
          sprintf(field, "WAT.%c%s", (m<2)?'X':'Y', (m%2)?"MAX":"MIN");
-@@ -25891,7 +25888,7 @@ int wcspih_final(
+         dpfill(disp->dp+(idp++), "DQ", field, i+1, 1, 0, wval);
+@@ -25891,9 +25888,9 @@ int wcspih_final(
          wp++;
        }
  
 -      /* Read the coefficients. */
+-      for (n = 0; n < wctrl[2]; n++) {
+-        for (m = 0; m < wctrl[1]; m++) {
 +      // Read the coefficients.
-       for (n = 0; n < wctrl[2]; n++) {
-         for (m = 0; m < wctrl[1]; m++) {
++      for (int n = 0; n < wctrl[2]; n++) {
++        for (int m = 0; m < wctrl[1]; m++) {
            if (wctrl[3] == 0) {
-Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
+             if (m && n) continue;
+           } else if (wctrl[3] == 2) {
+Index: astropy-4.2.1/cextern/wcslib/C/flexed/wcsulex.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/flexed/wcsulex.c
-+++ astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/flexed/wcsulex.c
++++ astropy-4.2.1/cextern/wcslib/C/flexed/wcsulex.c
 @@ -7150,9 +7150,8 @@ static const yy_state_type yy_NUL_trans[
  #define YY_RESTORE_YY_MORE_OFFSET
  #line 1 "wcsulex.l"
@@ -10918,7 +12372,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -10932,7 +12386,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcsulex.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcsulex.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcsulex.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
  * wcsulex.l is a Flex description file containing the definition of a
@@ -10941,27 +12395,49 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  /* Exclusive start states. */
  
 -#line 87 "wcsulex.l"
-+#line 84 "wcsulex.l"
++#line 85 "wcsulex.l"
  #include <math.h>
  #include <setjmp.h>
  #include <stdio.h>
-@@ -7213,7 +7210,7 @@ static int wcsulex_scanner(const char un
-                            double units[WCSUNITS_NTYPE], struct wcserr **err,
-                            yyscan_t yyscanner);
+@@ -7209,47 +7206,27 @@ static const yy_state_type yy_NUL_trans[
+ #include "wcsunits.h"
+ #include "wcsutil.h"
  
+-static int wcsulex_scanner(const char unitstr[], int *func, double *scale,
+-                           double units[WCSUNITS_NTYPE], struct wcserr **err,
+-                           yyscan_t yyscanner);
+-
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
- 
- int wcsulexe(
-   const char unitstr[],
-@@ -7235,21 +7232,21 @@ int wcsulexe(
-   return status;
- }
- 
+-
+-int wcsulexe(
+-  const char unitstr[],
+-  int *func,
+-  double *scale,
+-  double units[WCSUNITS_NTYPE],
+-  struct wcserr **err)
+-
+-{
+-  int status;
+-  yyscan_t yyscanner;
+-  int yylex_init(yyscan_t *yyscanner);
+-  int yylex_destroy(yyscan_t yyscanner);
+-
+-  yylex_init(&yyscanner);
+-  status = wcsulex_scanner(unitstr, func, scale, units, err, yyscanner);
+-  yylex_destroy(yyscanner);
+-
+-  return status;
+-}
+-
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
++// User data associated with yyscanner.
++struct wcsulex_extra {
++  // Used in preempting the call to exit() by yy_fatal_error().
++  jmp_buf abort_jmp_env;
++};
  
- #define YY_DECL int wcsulex_scanner(const char unitstr[], int *func, \
+-#define YY_DECL int wcsulex_scanner(const char unitstr[], int *func, \
++#define YY_DECL int wcsulexe_scanner(const char unitstr[], int *func, \
   double *scale, double units[WCSUNITS_NTYPE], struct wcserr **err, \
   yyscan_t yyscanner)
  
@@ -10970,32 +12446,82 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  #define YY_INPUT(inbuff, count, bufsize) { count = YY_NULL; }
  
 -/* Used in preempting the call to exit() by yy_fatal_error(). */
-+// Used in preempting the call to exit() by yy_fatal_error().
- jmp_buf wcsulex_abort_jmp_env;
- #define exit(status) longjmp(wcsulex_abort_jmp_env, status)
+-jmp_buf wcsulex_abort_jmp_env;
+-#define exit(status) longjmp(wcsulex_abort_jmp_env, status)
++// Preempt the call to exit() by yy_fatal_error().
++#define exit(status) longjmp(yyextra->abort_jmp_env, status);
++
++// Internal helper functions.
++static YY_DECL;
  
 -#line 7252 "wcsulex.c"
 -#line 7253 "wcsulex.c"
-+#line 7249 "wcsulex.c"
-+#line 7250 "wcsulex.c"
++#line 7229 "wcsulex.c"
++#line 7230 "wcsulex.c"
  
  #define INITIAL 0
  #define PAREN 1
-@@ -7501,9 +7498,9 @@ YY_DECL
+@@ -7266,9 +7243,7 @@ jmp_buf wcsulex_abort_jmp_env;
+ #include <unistd.h>
+ #endif
+ 
+-#ifndef YY_EXTRA_TYPE
+-#define YY_EXTRA_TYPE void *
+-#endif
++#define YY_EXTRA_TYPE struct wcsulex_extra *
+ 
+ /* Holds the entire state of the reentrant scanner. */
+ struct yyguts_t
+@@ -7501,42 +7476,45 @@ YY_DECL
  		}
  
  	{
 -#line 138 "wcsulex.l"
-+#line 135 "wcsulex.l"
++#line 116 "wcsulex.l"
  
 -#line 140 "wcsulex.l"
-+#line 137 "wcsulex.l"
- 	static const char *function = "wcsulexe";
+-	static const char *function = "wcsulexe";
++#line 118 "wcsulex.l"
++	static const char *function = "wcsulexe_scanner";
  	
- 	char ctmp[72];
-@@ -7528,14 +7525,14 @@ YY_DECL
- 	factor = 1.0;
- 	*scale = 1.0;
+-	char ctmp[72];
+-	int bracket  = 0;
+-	int operator = 0;
+-	int paren    = 0;
+-	int status   = 0;
+-	int func_r, i, j;
+-	double dexp, expon, factor, factor_r, types[WCSUNITS_NTYPE];
+-	YY_BUFFER_STATE buf;
+ 	void add(double *factor, double types[], double *expon, double *scale,
+ 	    double units[]);
+ 	
+-	if (err) *err = 0x0;
++	// Initialise returned values.
++	*func  = 0;
++	*scale = 1.0;
+ 	
+-	*func = 0;
+-	for (i = 0; i < WCSUNITS_NTYPE; i++) {
++	for (int i = 0; i < WCSUNITS_NTYPE; i++) {
+ 	  units[i] = 0.0;
++	}
++	
++	if (err) *err = 0x0;
++	
++	double types[WCSUNITS_NTYPE];
++	for (int i = 0; i < WCSUNITS_NTYPE; i++) {
+ 	  types[i] = 0.0;
+ 	}
+-	expon  = 1.0;
+-	factor = 1.0;
+-	*scale = 1.0;
++	double expon  = 1.0;
++	double factor = 1.0;
++	
++	int bracket  = 0;
++	int operator = 0;
++	int paren    = 0;
++	int status   = 0;
  	
 -	/* Avert a flex-induced memory leak. */
 +	// Avert a flex-induced memory leak.
@@ -11006,25 +12532,27 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  	yy_scan_string(unitstr, yyscanner);
  	
 -	/* Return here via longjmp() invoked by yy_fatal_error(). */
+-	if (setjmp(wcsulex_abort_jmp_env)) {
 +	// Return here via longjmp() invoked by yy_fatal_error().
- 	if (setjmp(wcsulex_abort_jmp_env)) {
++	if (setjmp(yyextra->abort_jmp_env)) {
  	  return wcserr_set(WCSERR_SET(UNITSERR_PARSER_ERROR),
  	    "Internal units parser error parsing '%s'", unitstr);
-@@ -7547,7 +7544,7 @@ YY_DECL
+ 	}
+@@ -7547,7 +7525,7 @@ YY_DECL
  	fprintf(stderr, "\n%s ->\n", unitstr);
  #endif
  
 -#line 7551 "wcsulex.c"
-+#line 7548 "wcsulex.c"
++#line 7529 "wcsulex.c"
  
  	while ( /*CONSTCOND*/1 )		/* loops until end-of-file is reached */
  		{
-@@ -7601,15 +7598,15 @@ do_action:	/* This label is used only to
+@@ -7601,15 +7579,15 @@ do_action:	/* This label is used only to
  
  case 1:
  YY_RULE_SETUP
 -#line 183 "wcsulex.l"
-+#line 180 "wcsulex.l"
++#line 164 "wcsulex.l"
  {
 -	  /* Pretend initial whitespace doesn't exist. */
 +	  // Pretend initial whitespace doesn't exist.
@@ -11034,89 +12562,89 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 2:
  YY_RULE_SETUP
 -#line 188 "wcsulex.l"
-+#line 185 "wcsulex.l"
++#line 169 "wcsulex.l"
  {
  	  if (bracket++) {
  	    BEGIN(FLUSH);
-@@ -7620,7 +7617,7 @@ YY_RULE_SETUP
+@@ -7620,7 +7598,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 3:
  YY_RULE_SETUP
 -#line 196 "wcsulex.l"
-+#line 193 "wcsulex.l"
++#line 177 "wcsulex.l"
  {
  	  status = wcserr_set(WCSERR_SET(UNITSERR_BAD_NUM_MULTIPLIER),
  	    "Invalid exponent in '%s'", unitstr);
-@@ -7629,7 +7626,7 @@ YY_RULE_SETUP
+@@ -7629,7 +7607,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 4:
  YY_RULE_SETUP
 -#line 202 "wcsulex.l"
-+#line 199 "wcsulex.l"
++#line 183 "wcsulex.l"
  {
  	  factor = 10.0;
  	  BEGIN(EXPON);
-@@ -7637,7 +7634,7 @@ YY_RULE_SETUP
+@@ -7637,7 +7615,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 5:
  YY_RULE_SETUP
 -#line 207 "wcsulex.l"
-+#line 204 "wcsulex.l"
++#line 188 "wcsulex.l"
  {
  	  *func = 1;
  	  unput('(');
-@@ -7646,7 +7643,7 @@ YY_RULE_SETUP
+@@ -7646,7 +7624,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 6:
  YY_RULE_SETUP
 -#line 213 "wcsulex.l"
-+#line 210 "wcsulex.l"
++#line 194 "wcsulex.l"
  {
  	  *func = 2;
  	  unput('(');
-@@ -7655,7 +7652,7 @@ YY_RULE_SETUP
+@@ -7655,7 +7633,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 7:
  YY_RULE_SETUP
 -#line 219 "wcsulex.l"
-+#line 216 "wcsulex.l"
++#line 200 "wcsulex.l"
  {
  	  *func = 3;
  	  unput('(');
-@@ -7664,9 +7661,9 @@ YY_RULE_SETUP
+@@ -7664,9 +7642,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 8:
  YY_RULE_SETUP
 -#line 225 "wcsulex.l"
-+#line 222 "wcsulex.l"
++#line 206 "wcsulex.l"
  {
 -	  /* Leading binary multiply. */
 +	  // Leading binary multiply.
  	  status = wcserr_set(WCSERR_SET(UNITSERR_DANGLING_BINOP),
  	    "Dangling binary operator in '%s'", unitstr);
  	  BEGIN(FLUSH);
-@@ -7674,12 +7671,12 @@ YY_RULE_SETUP
+@@ -7674,12 +7652,12 @@ YY_RULE_SETUP
  	YY_BREAK
  case 9:
  YY_RULE_SETUP
 -#line 232 "wcsulex.l"
 -/* Discard whitespace in INITIAL context. */
-+#line 229 "wcsulex.l"
++#line 213 "wcsulex.l"
 +// Discard whitespace in INITIAL context.
  	YY_BREAK
  case 10:
  YY_RULE_SETUP
 -#line 234 "wcsulex.l"
-+#line 231 "wcsulex.l"
++#line 215 "wcsulex.l"
  {
  	  expon /= 2.0;
  	  unput('(');
-@@ -7688,16 +7685,16 @@ YY_RULE_SETUP
+@@ -7688,16 +7666,16 @@ YY_RULE_SETUP
  	YY_BREAK
  case 11:
  YY_RULE_SETUP
 -#line 240 "wcsulex.l"
-+#line 237 "wcsulex.l"
++#line 221 "wcsulex.l"
  {
 -	  /* Gather terms in parentheses. */
 +	  // Gather terms in parentheses.
@@ -11127,81 +12655,81 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 12:
  YY_RULE_SETUP
 -#line 246 "wcsulex.l"
-+#line 243 "wcsulex.l"
++#line 227 "wcsulex.l"
  {
  	  if (operator++) {
  	    BEGIN(FLUSH);
-@@ -7705,10 +7702,10 @@ YY_RULE_SETUP
+@@ -7705,10 +7683,10 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 13:
 -#line 253 "wcsulex.l"
-+#line 250 "wcsulex.l"
++#line 234 "wcsulex.l"
  case 14:
  YY_RULE_SETUP
 -#line 253 "wcsulex.l"
-+#line 250 "wcsulex.l"
++#line 234 "wcsulex.l"
  {
  	  if (operator++) {
  	    BEGIN(FLUSH);
-@@ -7719,7 +7716,7 @@ YY_RULE_SETUP
+@@ -7719,7 +7697,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 15:
  YY_RULE_SETUP
 -#line 261 "wcsulex.l"
-+#line 258 "wcsulex.l"
++#line 242 "wcsulex.l"
  {
  	  operator = 0;
  	  yyless(0);
-@@ -7727,12 +7724,12 @@ YY_RULE_SETUP
+@@ -7727,12 +7705,12 @@ YY_RULE_SETUP
  	}
  	YY_BREAK
  case 16:
 -#line 268 "wcsulex.l"
-+#line 265 "wcsulex.l"
++#line 249 "wcsulex.l"
  case 17:
 -#line 269 "wcsulex.l"
-+#line 266 "wcsulex.l"
++#line 250 "wcsulex.l"
  case 18:
  YY_RULE_SETUP
 -#line 269 "wcsulex.l"
-+#line 266 "wcsulex.l"
++#line 250 "wcsulex.l"
  {
  	  operator = 0;
  	  yyless(0);
-@@ -7741,7 +7738,7 @@ YY_RULE_SETUP
+@@ -7741,7 +7719,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 19:
  YY_RULE_SETUP
 -#line 275 "wcsulex.l"
-+#line 272 "wcsulex.l"
++#line 256 "wcsulex.l"
  {
  	  bracket = !bracket;
  	  BEGIN(FLUSH);
-@@ -7749,7 +7746,7 @@ YY_RULE_SETUP
+@@ -7749,7 +7727,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 20:
  YY_RULE_SETUP
 -#line 280 "wcsulex.l"
-+#line 277 "wcsulex.l"
++#line 261 "wcsulex.l"
  {
  	  status = wcserr_set(WCSERR_SET(UNITSERR_BAD_INITIAL_SYMBOL),
  	    "Invalid symbol in INITIAL context in '%s'", unitstr);
-@@ -7758,7 +7755,7 @@ YY_RULE_SETUP
+@@ -7758,7 +7736,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 21:
  YY_RULE_SETUP
 -#line 286 "wcsulex.l"
-+#line 283 "wcsulex.l"
++#line 267 "wcsulex.l"
  {
  	  paren++;
  	  operator = 0;
-@@ -7767,15 +7764,15 @@ YY_RULE_SETUP
+@@ -7767,19 +7745,22 @@ YY_RULE_SETUP
  	YY_BREAK
  case 22:
  YY_RULE_SETUP
 -#line 292 "wcsulex.l"
-+#line 289 "wcsulex.l"
++#line 273 "wcsulex.l"
  {
  	  paren--;
  	  if (paren) {
@@ -11214,13 +12742,21 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
 +	    // Balanced; strip off the outer parentheses and recurse.
  	    yytext[yyleng-1] = '\0';
  	
- 	    buf = YY_CURRENT_BUFFER;
-@@ -7799,14 +7796,14 @@ YY_RULE_SETUP
+-	    buf = YY_CURRENT_BUFFER;
++	    int func_r;
++	    double factor_r;
+ 	    status = wcsulexe(yytext+1, &func_r, &factor_r, types, err);
++	
++	    YY_BUFFER_STATE buf = YY_CURRENT_BUFFER;
+ 	    yy_switch_to_buffer(buf, yyscanner);
+ 	
+ 	    if (func_r) {
+@@ -7799,14 +7780,14 @@ YY_RULE_SETUP
  case 23:
  /* rule 23 can match eol */
  YY_RULE_SETUP
 -#line 320 "wcsulex.l"
-+#line 317 "wcsulex.l"
++#line 304 "wcsulex.l"
  {
  	  yymore();
  	}
@@ -11228,223 +12764,223 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 24:
  YY_RULE_SETUP
 -#line 324 "wcsulex.l"
-+#line 321 "wcsulex.l"
++#line 308 "wcsulex.l"
  {
  	  factor = 1e-1;
  	  BEGIN(UNITS);
-@@ -7814,7 +7811,7 @@ YY_RULE_SETUP
+@@ -7814,7 +7795,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 25:
  YY_RULE_SETUP
 -#line 329 "wcsulex.l"
-+#line 326 "wcsulex.l"
++#line 313 "wcsulex.l"
  {
  	  factor = 1e-2;
  	  BEGIN(UNITS);
-@@ -7822,7 +7819,7 @@ YY_RULE_SETUP
+@@ -7822,7 +7803,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 26:
  YY_RULE_SETUP
 -#line 334 "wcsulex.l"
-+#line 331 "wcsulex.l"
++#line 318 "wcsulex.l"
  {
  	  factor = 1e-3;
  	  BEGIN(UNITS);
-@@ -7830,7 +7827,7 @@ YY_RULE_SETUP
+@@ -7830,7 +7811,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 27:
  YY_RULE_SETUP
 -#line 339 "wcsulex.l"
-+#line 336 "wcsulex.l"
++#line 323 "wcsulex.l"
  {
  	  factor = 1e-6;
  	  BEGIN(UNITS);
-@@ -7838,7 +7835,7 @@ YY_RULE_SETUP
+@@ -7838,7 +7819,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 28:
  YY_RULE_SETUP
 -#line 344 "wcsulex.l"
-+#line 341 "wcsulex.l"
++#line 328 "wcsulex.l"
  {
  	  factor = 1e-9;
  	  BEGIN(UNITS);
-@@ -7846,7 +7843,7 @@ YY_RULE_SETUP
+@@ -7846,7 +7827,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 29:
  YY_RULE_SETUP
 -#line 349 "wcsulex.l"
-+#line 346 "wcsulex.l"
++#line 333 "wcsulex.l"
  {
  	  factor = 1e-12;
  	  BEGIN(UNITS);
-@@ -7854,7 +7851,7 @@ YY_RULE_SETUP
+@@ -7854,7 +7835,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 30:
  YY_RULE_SETUP
 -#line 354 "wcsulex.l"
-+#line 351 "wcsulex.l"
++#line 338 "wcsulex.l"
  {
  	  factor = 1e-15;
  	  BEGIN(UNITS);
-@@ -7862,7 +7859,7 @@ YY_RULE_SETUP
+@@ -7862,7 +7843,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 31:
  YY_RULE_SETUP
 -#line 359 "wcsulex.l"
-+#line 356 "wcsulex.l"
++#line 343 "wcsulex.l"
  {
  	  factor = 1e-18;
  	  BEGIN(UNITS);
-@@ -7870,7 +7867,7 @@ YY_RULE_SETUP
+@@ -7870,7 +7851,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 32:
  YY_RULE_SETUP
 -#line 364 "wcsulex.l"
-+#line 361 "wcsulex.l"
++#line 348 "wcsulex.l"
  {
  	  factor = 1e-21;
  	  BEGIN(UNITS);
-@@ -7878,7 +7875,7 @@ YY_RULE_SETUP
+@@ -7878,7 +7859,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 33:
  YY_RULE_SETUP
 -#line 369 "wcsulex.l"
-+#line 366 "wcsulex.l"
++#line 353 "wcsulex.l"
  {
  	  factor = 1e-24;
  	  BEGIN(UNITS);
-@@ -7886,7 +7883,7 @@ YY_RULE_SETUP
+@@ -7886,7 +7867,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 34:
  YY_RULE_SETUP
 -#line 374 "wcsulex.l"
-+#line 371 "wcsulex.l"
++#line 358 "wcsulex.l"
  {
  	  factor = 1e+1;
  	  BEGIN(UNITS);
-@@ -7894,7 +7891,7 @@ YY_RULE_SETUP
+@@ -7894,7 +7875,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 35:
  YY_RULE_SETUP
 -#line 379 "wcsulex.l"
-+#line 376 "wcsulex.l"
++#line 363 "wcsulex.l"
  {
  	  factor = 1e+2;
  	  BEGIN(UNITS);
-@@ -7902,7 +7899,7 @@ YY_RULE_SETUP
+@@ -7902,7 +7883,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 36:
  YY_RULE_SETUP
 -#line 384 "wcsulex.l"
-+#line 381 "wcsulex.l"
++#line 368 "wcsulex.l"
  {
  	  factor = 1e+3;
  	  BEGIN(UNITS);
-@@ -7910,7 +7907,7 @@ YY_RULE_SETUP
+@@ -7910,7 +7891,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 37:
  YY_RULE_SETUP
 -#line 389 "wcsulex.l"
-+#line 386 "wcsulex.l"
++#line 373 "wcsulex.l"
  {
  	  factor = 1e+6;
  	  BEGIN(UNITS);
-@@ -7918,7 +7915,7 @@ YY_RULE_SETUP
+@@ -7918,7 +7899,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 38:
  YY_RULE_SETUP
 -#line 394 "wcsulex.l"
-+#line 391 "wcsulex.l"
++#line 378 "wcsulex.l"
  {
  	  factor = 1e+9;
  	  BEGIN(UNITS);
-@@ -7926,7 +7923,7 @@ YY_RULE_SETUP
+@@ -7926,7 +7907,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 39:
  YY_RULE_SETUP
 -#line 399 "wcsulex.l"
-+#line 396 "wcsulex.l"
++#line 383 "wcsulex.l"
  {
  	  factor = 1e+12;
  	  BEGIN(UNITS);
-@@ -7934,7 +7931,7 @@ YY_RULE_SETUP
+@@ -7934,7 +7915,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 40:
  YY_RULE_SETUP
 -#line 404 "wcsulex.l"
-+#line 401 "wcsulex.l"
++#line 388 "wcsulex.l"
  {
  	  factor = 1e+15;
  	  BEGIN(UNITS);
-@@ -7942,7 +7939,7 @@ YY_RULE_SETUP
+@@ -7942,7 +7923,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 41:
  YY_RULE_SETUP
 -#line 409 "wcsulex.l"
-+#line 406 "wcsulex.l"
++#line 393 "wcsulex.l"
  {
  	  factor = 1e+18;
  	  BEGIN(UNITS);
-@@ -7950,7 +7947,7 @@ YY_RULE_SETUP
+@@ -7950,7 +7931,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 42:
  YY_RULE_SETUP
 -#line 414 "wcsulex.l"
-+#line 411 "wcsulex.l"
++#line 398 "wcsulex.l"
  {
  	  factor = 1e+21;
  	  BEGIN(UNITS);
-@@ -7958,7 +7955,7 @@ YY_RULE_SETUP
+@@ -7958,7 +7939,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 43:
  YY_RULE_SETUP
 -#line 419 "wcsulex.l"
-+#line 416 "wcsulex.l"
++#line 403 "wcsulex.l"
  {
  	  factor = 1e+24;
  	  BEGIN(UNITS);
-@@ -7966,9 +7963,9 @@ YY_RULE_SETUP
+@@ -7966,9 +7947,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 44:
  YY_RULE_SETUP
 -#line 424 "wcsulex.l"
-+#line 421 "wcsulex.l"
++#line 408 "wcsulex.l"
  {
 -	  /* Internal parser error. */
 +	  // Internal parser error.
  	  status = wcserr_set(WCSERR_SET(UNITSERR_PARSER_ERROR),
  	    "Internal units parser error parsing '%s'", unitstr);
  	  BEGIN(FLUSH);
-@@ -7976,9 +7973,9 @@ YY_RULE_SETUP
+@@ -7976,9 +7957,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 45:
  YY_RULE_SETUP
 -#line 431 "wcsulex.l"
-+#line 428 "wcsulex.l"
++#line 415 "wcsulex.l"
  {
 -	  /* Ampere. */
 +	  // Ampere.
  	  types[WCSUNITS_CHARGE] += 1.0;
  	  types[WCSUNITS_TIME]   -= 1.0;
  	  BEGIN(EXPON);
-@@ -7986,9 +7983,9 @@ YY_RULE_SETUP
+@@ -7986,9 +7967,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 46:
  YY_RULE_SETUP
 -#line 438 "wcsulex.l"
-+#line 435 "wcsulex.l"
++#line 422 "wcsulex.l"
  {
 -	  /* Julian year (annum). */
 +	  // Julian year (annum).
  	  factor *= 31557600.0;
  	  types[WCSUNITS_TIME] += 1.0;
  	  BEGIN(EXPON);
-@@ -7996,18 +7993,18 @@ YY_RULE_SETUP
+@@ -7996,18 +7977,18 @@ YY_RULE_SETUP
  	YY_BREAK
  case 47:
  YY_RULE_SETUP
 -#line 445 "wcsulex.l"
-+#line 442 "wcsulex.l"
++#line 429 "wcsulex.l"
  {
 -	  /* Analogue-to-digital converter units. */
 +	  // Analogue-to-digital converter units.
@@ -11455,67 +12991,67 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 48:
  YY_RULE_SETUP
 -#line 451 "wcsulex.l"
-+#line 448 "wcsulex.l"
++#line 435 "wcsulex.l"
  {
 -	  /* Angstrom. */
 +	  // Angstrom.
  	  factor *= 1e-10;
  	  types[WCSUNITS_LENGTH] += 1.0;
  	  BEGIN(EXPON);
-@@ -8015,9 +8012,9 @@ YY_RULE_SETUP
+@@ -8015,9 +7996,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 49:
  YY_RULE_SETUP
 -#line 458 "wcsulex.l"
-+#line 455 "wcsulex.l"
++#line 442 "wcsulex.l"
  {
 -	  /* Minute of arc. */
 +	  // Minute of arc.
  	  factor /= 60.0;
  	  types[WCSUNITS_PLANE_ANGLE] += 1.0;
  	  BEGIN(EXPON);
-@@ -8025,9 +8022,9 @@ YY_RULE_SETUP
+@@ -8025,9 +8006,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 50:
  YY_RULE_SETUP
 -#line 465 "wcsulex.l"
-+#line 462 "wcsulex.l"
++#line 449 "wcsulex.l"
  {
 -	  /* Second of arc. */
 +	  // Second of arc.
  	  factor /= 3600.0;
  	  types[WCSUNITS_PLANE_ANGLE] += 1.0;
  	  BEGIN(EXPON);
-@@ -8035,9 +8032,9 @@ YY_RULE_SETUP
+@@ -8035,9 +8016,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 51:
  YY_RULE_SETUP
 -#line 472 "wcsulex.l"
-+#line 469 "wcsulex.l"
++#line 456 "wcsulex.l"
  {
 -	  /* Astronomical unit. */
 +	  // Astronomical unit.
  	  factor *= 1.49598e+11;
  	  types[WCSUNITS_LENGTH] += 1.0;
  	  BEGIN(EXPON);
-@@ -8045,9 +8042,9 @@ YY_RULE_SETUP
+@@ -8045,9 +8026,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 52:
  YY_RULE_SETUP
 -#line 479 "wcsulex.l"
-+#line 476 "wcsulex.l"
++#line 463 "wcsulex.l"
  {
 -	  /* Barn. */
 +	  // Barn.
  	  factor *= 1e-28;
  	  types[WCSUNITS_LENGTH] += 2.0;
  	  BEGIN(EXPON);
-@@ -8055,36 +8052,36 @@ YY_RULE_SETUP
+@@ -8055,36 +8036,36 @@ YY_RULE_SETUP
  	YY_BREAK
  case 53:
  YY_RULE_SETUP
 -#line 486 "wcsulex.l"
-+#line 483 "wcsulex.l"
++#line 470 "wcsulex.l"
  {
 -	  /* Beam, as in Jy/beam. */
 +	  // Beam, as in Jy/beam.
@@ -11526,7 +13062,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 54:
  YY_RULE_SETUP
 -#line 492 "wcsulex.l"
-+#line 489 "wcsulex.l"
++#line 476 "wcsulex.l"
  {
 -	  /* Bin (e.g. histogram). */
 +	  // Bin (e.g. histogram).
@@ -11537,7 +13073,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 55:
  YY_RULE_SETUP
 -#line 498 "wcsulex.l"
-+#line 495 "wcsulex.l"
++#line 482 "wcsulex.l"
  {
 -	  /* Bit. */
 +	  // Bit.
@@ -11548,19 +13084,19 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 56:
  YY_RULE_SETUP
 -#line 504 "wcsulex.l"
-+#line 501 "wcsulex.l"
++#line 488 "wcsulex.l"
  {
 -	  /* Byte. */
 +	  // Byte.
  	  factor *= 8.0;
  	  types[WCSUNITS_BIT] += 1.0;
  	  BEGIN(EXPON);
-@@ -8092,45 +8089,45 @@ YY_RULE_SETUP
+@@ -8092,45 +8073,45 @@ YY_RULE_SETUP
  	YY_BREAK
  case 57:
  YY_RULE_SETUP
 -#line 511 "wcsulex.l"
-+#line 508 "wcsulex.l"
++#line 495 "wcsulex.l"
  {
 -	  /* Coulomb. */
 +	  // Coulomb.
@@ -11571,7 +13107,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 58:
  YY_RULE_SETUP
 -#line 517 "wcsulex.l"
-+#line 514 "wcsulex.l"
++#line 501 "wcsulex.l"
  {
 -	  /* Candela. */
 +	  // Candela.
@@ -11582,7 +13118,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 59:
  YY_RULE_SETUP
 -#line 523 "wcsulex.l"
-+#line 520 "wcsulex.l"
++#line 507 "wcsulex.l"
  {
 -	  /* Channel. */
 +	  // Channel.
@@ -11593,7 +13129,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 60:
  YY_RULE_SETUP
 -#line 529 "wcsulex.l"
-+#line 526 "wcsulex.l"
++#line 513 "wcsulex.l"
  {
 -	  /* Count. */
 +	  // Count.
@@ -11604,43 +13140,43 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 61:
  YY_RULE_SETUP
 -#line 535 "wcsulex.l"
-+#line 532 "wcsulex.l"
++#line 519 "wcsulex.l"
  {
 -	  /* Julian century. */
 +	  // Julian century.
  	  factor *= 3155760000.0;
  	  types[WCSUNITS_TIME] += 1.0;
  	  BEGIN(EXPON);
-@@ -8138,9 +8135,9 @@ YY_RULE_SETUP
+@@ -8138,9 +8119,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 62:
  YY_RULE_SETUP
 -#line 542 "wcsulex.l"
-+#line 539 "wcsulex.l"
++#line 526 "wcsulex.l"
  {
 -	  /* Debye. */
 +	  // Debye.
  	  factor *= 1e-29 / 3.0;
  	  types[WCSUNITS_CHARGE] += 1.0;
  	  types[WCSUNITS_LENGTH] += 1.0;
-@@ -8149,9 +8146,9 @@ YY_RULE_SETUP
+@@ -8149,9 +8130,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 63:
  YY_RULE_SETUP
 -#line 550 "wcsulex.l"
-+#line 547 "wcsulex.l"
++#line 534 "wcsulex.l"
  {
 -	  /* Day. */
 +	  // Day.
  	  factor *= 86400.0;
  	  types[WCSUNITS_TIME] += 1.0;
  	  BEGIN(EXPON);
-@@ -8159,18 +8156,18 @@ YY_RULE_SETUP
+@@ -8159,18 +8140,18 @@ YY_RULE_SETUP
  	YY_BREAK
  case 64:
  YY_RULE_SETUP
 -#line 557 "wcsulex.l"
-+#line 554 "wcsulex.l"
++#line 541 "wcsulex.l"
  {
 -	  /* Degree. */
 +	  // Degree.
@@ -11651,91 +13187,91 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 65:
  YY_RULE_SETUP
 -#line 563 "wcsulex.l"
-+#line 560 "wcsulex.l"
++#line 547 "wcsulex.l"
  {
 -	  /* Erg. */
 +	  // Erg.
  	  factor *= 1e-7;
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
-@@ -8180,9 +8177,9 @@ YY_RULE_SETUP
+@@ -8180,9 +8161,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 66:
  YY_RULE_SETUP
 -#line 572 "wcsulex.l"
-+#line 569 "wcsulex.l"
++#line 556 "wcsulex.l"
  {
 -	  /* Electron volt. */
 +	  // Electron volt.
  	  factor *= 1.6021765e-19;
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
-@@ -8192,9 +8189,9 @@ YY_RULE_SETUP
+@@ -8192,9 +8173,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 67:
  YY_RULE_SETUP
 -#line 581 "wcsulex.l"
-+#line 578 "wcsulex.l"
++#line 565 "wcsulex.l"
  {
 -	  /* Farad. */
 +	  // Farad.
  	  types[WCSUNITS_MASS]   -= 1.0;
  	  types[WCSUNITS_LENGTH] -= 2.0;
  	  types[WCSUNITS_TIME]   += 3.0;
-@@ -8204,9 +8201,9 @@ YY_RULE_SETUP
+@@ -8204,9 +8185,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 68:
  YY_RULE_SETUP
 -#line 590 "wcsulex.l"
-+#line 587 "wcsulex.l"
++#line 574 "wcsulex.l"
  {
 -	  /* Gauss. */
 +	  // Gauss.
  	  factor *= 1e-4;
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_TIME]   += 1.0;
-@@ -8216,9 +8213,9 @@ YY_RULE_SETUP
+@@ -8216,9 +8197,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 69:
  YY_RULE_SETUP
 -#line 599 "wcsulex.l"
-+#line 596 "wcsulex.l"
++#line 583 "wcsulex.l"
  {
 -	  /* Gram. */
 +	  // Gram.
  	  factor *= 1e-3;
  	  types[WCSUNITS_MASS] += 1.0;
  	  BEGIN(EXPON);
-@@ -8226,9 +8223,9 @@ YY_RULE_SETUP
+@@ -8226,9 +8207,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 70:
  YY_RULE_SETUP
 -#line 606 "wcsulex.l"
-+#line 603 "wcsulex.l"
++#line 590 "wcsulex.l"
  {
 -	  /* Henry. */
 +	  // Henry.
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
  	  types[WCSUNITS_TIME]   += 2.0;
-@@ -8238,9 +8235,9 @@ YY_RULE_SETUP
+@@ -8238,9 +8219,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 71:
  YY_RULE_SETUP
 -#line 615 "wcsulex.l"
-+#line 612 "wcsulex.l"
++#line 599 "wcsulex.l"
  {
 -	  /* Hour. */
 +	  // Hour.
  	  factor *= 3600.0;
  	  types[WCSUNITS_TIME] += 1.0;
  	  BEGIN(EXPON);
-@@ -8248,18 +8245,18 @@ YY_RULE_SETUP
+@@ -8248,18 +8229,18 @@ YY_RULE_SETUP
  	YY_BREAK
  case 72:
  YY_RULE_SETUP
 -#line 622 "wcsulex.l"
-+#line 619 "wcsulex.l"
++#line 606 "wcsulex.l"
  {
 -	  /* Hertz. */
 +	  // Hertz.
@@ -11746,31 +13282,31 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 73:
  YY_RULE_SETUP
 -#line 628 "wcsulex.l"
-+#line 625 "wcsulex.l"
++#line 612 "wcsulex.l"
  {
 -	  /* Joule. */
 +	  // Joule.
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
  	  types[WCSUNITS_TIME]   -= 2.0;
-@@ -8268,9 +8265,9 @@ YY_RULE_SETUP
+@@ -8268,9 +8249,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 74:
  YY_RULE_SETUP
 -#line 636 "wcsulex.l"
-+#line 633 "wcsulex.l"
++#line 620 "wcsulex.l"
  {
 -	  /* Jansky. */
 +	  // Jansky.
  	  factor *= 1e-26;
  	  types[WCSUNITS_MASS] += 1.0;
  	  types[WCSUNITS_TIME] -= 2.0;
-@@ -8279,18 +8276,18 @@ YY_RULE_SETUP
+@@ -8279,18 +8260,18 @@ YY_RULE_SETUP
  	YY_BREAK
  case 75:
  YY_RULE_SETUP
 -#line 644 "wcsulex.l"
-+#line 641 "wcsulex.l"
++#line 628 "wcsulex.l"
  {
 -	  /* Kelvin. */
 +	  // Kelvin.
@@ -11781,43 +13317,43 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 76:
  YY_RULE_SETUP
 -#line 650 "wcsulex.l"
-+#line 647 "wcsulex.l"
++#line 634 "wcsulex.l"
  {
 -	  /* Lumen. */
 +	  // Lumen.
  	  types[WCSUNITS_LUMINTEN]    += 1.0;
  	  types[WCSUNITS_SOLID_ANGLE] += 1.0;
  	  BEGIN(EXPON);
-@@ -8298,9 +8295,9 @@ YY_RULE_SETUP
+@@ -8298,9 +8279,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 77:
  YY_RULE_SETUP
 -#line 657 "wcsulex.l"
-+#line 654 "wcsulex.l"
++#line 641 "wcsulex.l"
  {
 -	  /* Lux. */
 +	  // Lux.
  	  types[WCSUNITS_LUMINTEN]    += 1.0;
  	  types[WCSUNITS_SOLID_ANGLE] += 1.0;
  	  types[WCSUNITS_LENGTH]      -= 2.0;
-@@ -8309,9 +8306,9 @@ YY_RULE_SETUP
+@@ -8309,9 +8290,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 78:
  YY_RULE_SETUP
 -#line 665 "wcsulex.l"
-+#line 662 "wcsulex.l"
++#line 649 "wcsulex.l"
  {
 -	  /* Light year. */
 +	  // Light year.
  	  factor *= 2.99792458e8 * 31557600.0;
  	  types[WCSUNITS_LENGTH] += 1.0;
  	  BEGIN(EXPON);
-@@ -8319,27 +8316,27 @@ YY_RULE_SETUP
+@@ -8319,27 +8300,27 @@ YY_RULE_SETUP
  	YY_BREAK
  case 79:
  YY_RULE_SETUP
 -#line 672 "wcsulex.l"
-+#line 669 "wcsulex.l"
++#line 656 "wcsulex.l"
  {
 -	  /* Metre. */
 +	  // Metre.
@@ -11828,7 +13364,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 80:
  YY_RULE_SETUP
 -#line 678 "wcsulex.l"
-+#line 675 "wcsulex.l"
++#line 662 "wcsulex.l"
  {
 -	  /* Stellar magnitude. */
 +	  // Stellar magnitude.
@@ -11839,31 +13375,31 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 81:
  YY_RULE_SETUP
 -#line 684 "wcsulex.l"
-+#line 681 "wcsulex.l"
++#line 668 "wcsulex.l"
  {
 -	  /* Milli-arcsec. */
 +	  // Milli-arcsec.
  	  factor /= 3600e+3;
  	  types[WCSUNITS_PLANE_ANGLE] += 1.0;
  	  BEGIN(EXPON);
-@@ -8347,9 +8344,9 @@ YY_RULE_SETUP
+@@ -8347,9 +8328,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 82:
  YY_RULE_SETUP
 -#line 691 "wcsulex.l"
-+#line 688 "wcsulex.l"
++#line 675 "wcsulex.l"
  {
 -	  /* Minute. */
 +	  // Minute.
  	  factor *= 60.0;
  	  types[WCSUNITS_TIME] += 1.0;
  	  BEGIN(EXPON);
-@@ -8357,18 +8354,18 @@ YY_RULE_SETUP
+@@ -8357,18 +8338,18 @@ YY_RULE_SETUP
  	YY_BREAK
  case 83:
  YY_RULE_SETUP
 -#line 698 "wcsulex.l"
-+#line 695 "wcsulex.l"
++#line 682 "wcsulex.l"
  {
 -	  /* Mole. */
 +	  // Mole.
@@ -11874,55 +13410,55 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 84:
  YY_RULE_SETUP
 -#line 704 "wcsulex.l"
-+#line 701 "wcsulex.l"
++#line 688 "wcsulex.l"
  {
 -	  /* Newton. */
 +	  // Newton.
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 1.0;
  	  types[WCSUNITS_TIME]   -= 2.0;
-@@ -8377,9 +8374,9 @@ YY_RULE_SETUP
+@@ -8377,9 +8358,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 85:
  YY_RULE_SETUP
 -#line 712 "wcsulex.l"
-+#line 709 "wcsulex.l"
++#line 696 "wcsulex.l"
  {
 -	  /* Ohm. */
 +	  // Ohm.
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
  	  types[WCSUNITS_TIME]   -= 1.0;
-@@ -8389,9 +8386,9 @@ YY_RULE_SETUP
+@@ -8389,9 +8370,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 86:
  YY_RULE_SETUP
 -#line 721 "wcsulex.l"
-+#line 718 "wcsulex.l"
++#line 705 "wcsulex.l"
  {
 -	  /* Pascal. */
 +	  // Pascal.
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] -= 1.0;
  	  types[WCSUNITS_TIME]   -= 2.0;
-@@ -8400,9 +8397,9 @@ YY_RULE_SETUP
+@@ -8400,9 +8381,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 87:
  YY_RULE_SETUP
 -#line 729 "wcsulex.l"
-+#line 726 "wcsulex.l"
++#line 713 "wcsulex.l"
  {
 -	  /* Parsec. */
 +	  // Parsec.
  	  factor *= 3.0857e16;
  	  types[WCSUNITS_LENGTH] += 1.0;
  	  BEGIN(EXPON);
-@@ -8410,27 +8407,27 @@ YY_RULE_SETUP
+@@ -8410,27 +8391,27 @@ YY_RULE_SETUP
  	YY_BREAK
  case 88:
  YY_RULE_SETUP
 -#line 736 "wcsulex.l"
-+#line 733 "wcsulex.l"
++#line 720 "wcsulex.l"
  {
 -	  /* Photon. */
 +	  // Photon.
@@ -11933,7 +13469,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 89:
  YY_RULE_SETUP
 -#line 742 "wcsulex.l"
-+#line 739 "wcsulex.l"
++#line 726 "wcsulex.l"
  {
 -	  /* Pixel. */
 +	  // Pixel.
@@ -11944,55 +13480,55 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 90:
  YY_RULE_SETUP
 -#line 748 "wcsulex.l"
-+#line 745 "wcsulex.l"
++#line 732 "wcsulex.l"
  {
 -	  /* Rayleigh. */
 +	  // Rayleigh.
  	  factor *= 1e10 / (4.0 * PI);
  	  types[WCSUNITS_LENGTH]      -= 2.0;
  	  types[WCSUNITS_TIME]        -= 1.0;
-@@ -8440,9 +8437,9 @@ YY_RULE_SETUP
+@@ -8440,9 +8421,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 91:
  YY_RULE_SETUP
 -#line 757 "wcsulex.l"
-+#line 754 "wcsulex.l"
++#line 741 "wcsulex.l"
  {
 -	  /* Radian. */
 +	  // Radian.
  	  factor *= 180.0 / PI;
  	  types[WCSUNITS_PLANE_ANGLE] += 1.0;
  	  BEGIN(EXPON);
-@@ -8450,9 +8447,9 @@ YY_RULE_SETUP
+@@ -8450,9 +8431,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 92:
  YY_RULE_SETUP
 -#line 764 "wcsulex.l"
-+#line 761 "wcsulex.l"
++#line 748 "wcsulex.l"
  {
 -	  /* Rydberg. */
 +	  // Rydberg.
  	  factor *= 13.605692 * 1.6021765e-19;
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
-@@ -8462,9 +8459,9 @@ YY_RULE_SETUP
+@@ -8462,9 +8443,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 93:
  YY_RULE_SETUP
 -#line 773 "wcsulex.l"
-+#line 770 "wcsulex.l"
++#line 757 "wcsulex.l"
  {
 -	  /* Siemen. */
 +	  // Siemen.
  	  types[WCSUNITS_MASS]   -= 1.0;
  	  types[WCSUNITS_LENGTH] -= 2.0;
  	  types[WCSUNITS_TIME]   += 1.0;
-@@ -8474,18 +8471,18 @@ YY_RULE_SETUP
+@@ -8474,18 +8455,18 @@ YY_RULE_SETUP
  	YY_BREAK
  case 94:
  YY_RULE_SETUP
 -#line 782 "wcsulex.l"
-+#line 779 "wcsulex.l"
++#line 766 "wcsulex.l"
  {
 -	  /* Second. */
 +	  // Second.
@@ -12003,43 +13539,43 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 95:
  YY_RULE_SETUP
 -#line 788 "wcsulex.l"
-+#line 785 "wcsulex.l"
++#line 772 "wcsulex.l"
  {
 -	  /* Solar luminosity. */
 +	  // Solar luminosity.
  	  factor *= 3.8268e26;
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
-@@ -8495,9 +8492,9 @@ YY_RULE_SETUP
+@@ -8495,9 +8476,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 96:
  YY_RULE_SETUP
 -#line 797 "wcsulex.l"
-+#line 794 "wcsulex.l"
++#line 781 "wcsulex.l"
  {
 -	  /* Solar mass. */
 +	  // Solar mass.
  	  factor *= 1.9891e30;
  	  types[WCSUNITS_MASS] += 1.0;
  	  BEGIN(EXPON);
-@@ -8505,9 +8502,9 @@ YY_RULE_SETUP
+@@ -8505,9 +8486,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 97:
  YY_RULE_SETUP
 -#line 804 "wcsulex.l"
-+#line 801 "wcsulex.l"
++#line 788 "wcsulex.l"
  {
 -	  /* Solar radius. */
 +	  // Solar radius.
  	  factor *= 6.9599e8;
  	  types[WCSUNITS_LENGTH] += 1.0;
  	  BEGIN(EXPON);
-@@ -8515,27 +8512,27 @@ YY_RULE_SETUP
+@@ -8515,27 +8496,27 @@ YY_RULE_SETUP
  	YY_BREAK
  case 98:
  YY_RULE_SETUP
 -#line 811 "wcsulex.l"
-+#line 808 "wcsulex.l"
++#line 795 "wcsulex.l"
  {
 -	  /* Steradian. */
 +	  // Steradian.
@@ -12050,7 +13586,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 99:
  YY_RULE_SETUP
 -#line 817 "wcsulex.l"
-+#line 814 "wcsulex.l"
++#line 801 "wcsulex.l"
  {
 -	  /* Sun (with respect to). */
 +	  // Sun (with respect to).
@@ -12061,55 +13597,55 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 100:
  YY_RULE_SETUP
 -#line 823 "wcsulex.l"
-+#line 820 "wcsulex.l"
++#line 807 "wcsulex.l"
  {
 -	  /* Tesla. */
 +	  // Tesla.
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_TIME]   += 1.0;
  	  types[WCSUNITS_CHARGE] -= 1.0;
-@@ -8544,9 +8541,9 @@ YY_RULE_SETUP
+@@ -8544,9 +8525,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 101:
  YY_RULE_SETUP
 -#line 831 "wcsulex.l"
-+#line 828 "wcsulex.l"
++#line 815 "wcsulex.l"
  {
 -	  /* Turn. */
 +	  // Turn.
  	  factor *= 360.0;
  	  types[WCSUNITS_PLANE_ANGLE] += 1.0;
  	  BEGIN(EXPON);
-@@ -8554,9 +8551,9 @@ YY_RULE_SETUP
+@@ -8554,9 +8535,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 102:
  YY_RULE_SETUP
 -#line 838 "wcsulex.l"
-+#line 835 "wcsulex.l"
++#line 822 "wcsulex.l"
  {
 -	  /* Unified atomic mass unit. */
 +	  // Unified atomic mass unit.
  	  factor *= 1.6605387e-27;
  	  types[WCSUNITS_MASS] += 1.0;
  	  BEGIN(EXPON);
-@@ -8564,9 +8561,9 @@ YY_RULE_SETUP
+@@ -8564,9 +8545,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 103:
  YY_RULE_SETUP
 -#line 845 "wcsulex.l"
-+#line 842 "wcsulex.l"
++#line 829 "wcsulex.l"
  {
 -	  /* Volt. */
 +	  // Volt.
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 1.0;
  	  types[WCSUNITS_TIME]   -= 2.0;
-@@ -8576,18 +8573,18 @@ YY_RULE_SETUP
+@@ -8576,18 +8557,18 @@ YY_RULE_SETUP
  	YY_BREAK
  case 104:
  YY_RULE_SETUP
 -#line 854 "wcsulex.l"
-+#line 851 "wcsulex.l"
++#line 838 "wcsulex.l"
  {
 -	  /* Voxel. */
 +	  // Voxel.
@@ -12120,201 +13656,261 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsulex.c
  case 105:
  YY_RULE_SETUP
 -#line 860 "wcsulex.l"
-+#line 857 "wcsulex.l"
++#line 844 "wcsulex.l"
  {
 -	  /* Watt. */
 +	  // Watt.
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
  	  types[WCSUNITS_TIME]   -= 3.0;
-@@ -8596,9 +8593,9 @@ YY_RULE_SETUP
+@@ -8596,9 +8577,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 106:
  YY_RULE_SETUP
 -#line 868 "wcsulex.l"
-+#line 865 "wcsulex.l"
++#line 852 "wcsulex.l"
  {
 -	  /* Weber. */
 +	  // Weber.
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
  	  types[WCSUNITS_TIME]   += 1.0;
-@@ -8608,9 +8605,9 @@ YY_RULE_SETUP
+@@ -8608,9 +8589,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 107:
  YY_RULE_SETUP
 -#line 877 "wcsulex.l"
-+#line 874 "wcsulex.l"
++#line 861 "wcsulex.l"
  {
 -	  /* Internal parser error. */
 +	  // Internal parser error.
  	  status = wcserr_set(WCSERR_SET(UNITSERR_PARSER_ERROR),
  	    "Internal units parser error parsing '%s'", unitstr);
  	  BEGIN(FLUSH);
-@@ -8618,9 +8615,9 @@ YY_RULE_SETUP
+@@ -8618,9 +8599,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 108:
  YY_RULE_SETUP
 -#line 884 "wcsulex.l"
-+#line 881 "wcsulex.l"
++#line 868 "wcsulex.l"
  {
 -	  /* Exponentiation. */
 +	  // Exponentiation.
  	  if (operator++) {
  	    BEGIN(FLUSH);
  	  }
-@@ -8628,7 +8625,7 @@ YY_RULE_SETUP
+@@ -8628,8 +8609,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 109:
  YY_RULE_SETUP
 -#line 891 "wcsulex.l"
-+#line 888 "wcsulex.l"
++#line 875 "wcsulex.l"
  {
++	  int i;
  	  sscanf(yytext, " %d", &i);
  	  expon *= (double)i;
-@@ -8639,7 +8636,7 @@ YY_RULE_SETUP
+ 	  add(&factor, types, &expon, scale, units);
+@@ -8639,8 +8621,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 110:
  YY_RULE_SETUP
 -#line 899 "wcsulex.l"
-+#line 896 "wcsulex.l"
++#line 884 "wcsulex.l"
  {
++	  int i;
  	  sscanf(yytext, " (%d)", &i);
  	  expon *= (double)i;
-@@ -8650,7 +8647,7 @@ YY_RULE_SETUP
+ 	  add(&factor, types, &expon, scale, units);
+@@ -8650,8 +8633,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 111:
  YY_RULE_SETUP
 -#line 907 "wcsulex.l"
-+#line 904 "wcsulex.l"
++#line 893 "wcsulex.l"
  {
++	  int i, j;
  	  sscanf(yytext, " (%d/%d)", &i, &j);
  	  expon *= (double)i / (double)j;
-@@ -8661,7 +8658,7 @@ YY_RULE_SETUP
+ 	  add(&factor, types, &expon, scale, units);
+@@ -8661,9 +8645,11 @@ YY_RULE_SETUP
  	YY_BREAK
  case 112:
  YY_RULE_SETUP
 -#line 915 "wcsulex.l"
-+#line 912 "wcsulex.l"
++#line 902 "wcsulex.l"
  {
++	  char ctmp[72];
  	  sscanf(yytext, " (%s)", ctmp);
++	  double dexp;
  	  wcsutil_str2double(ctmp, &dexp);
-@@ -8673,9 +8670,9 @@ YY_RULE_SETUP
+ 	  expon *= dexp;
+ 	  add(&factor, types, &expon, scale, units);
+@@ -8673,9 +8659,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 113:
  YY_RULE_SETUP
 -#line 924 "wcsulex.l"
-+#line 921 "wcsulex.l"
++#line 913 "wcsulex.l"
  {
 -	  /* Multiply. */
 +	  // Multiply.
  	  if (operator++) {
  	    BEGIN(FLUSH);
  	  } else {
-@@ -8686,9 +8683,9 @@ YY_RULE_SETUP
+@@ -8686,9 +8672,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 114:
  YY_RULE_SETUP
 -#line 934 "wcsulex.l"
-+#line 931 "wcsulex.l"
++#line 923 "wcsulex.l"
  {
 -	  /* Multiply. */
 +	  // Multiply.
  	  if (operator) {
  	    BEGIN(FLUSH);
  	  } else {
-@@ -8700,9 +8697,9 @@ YY_RULE_SETUP
+@@ -8700,9 +8686,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 115:
  YY_RULE_SETUP
 -#line 945 "wcsulex.l"
-+#line 942 "wcsulex.l"
++#line 934 "wcsulex.l"
  {
 -	  /* Multiply. */
 +	  // Multiply.
  	  if (operator) {
  	    BEGIN(FLUSH);
  	  } else {
-@@ -8713,9 +8710,9 @@ YY_RULE_SETUP
+@@ -8713,9 +8699,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 116:
  YY_RULE_SETUP
 -#line 955 "wcsulex.l"
-+#line 952 "wcsulex.l"
++#line 944 "wcsulex.l"
  {
 -	  /* Divide. */
 +	  // Divide.
  	  if (operator++) {
  	    BEGIN(FLUSH);
  	  } else {
-@@ -8727,7 +8724,7 @@ YY_RULE_SETUP
+@@ -8727,7 +8713,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 117:
  YY_RULE_SETUP
 -#line 966 "wcsulex.l"
-+#line 963 "wcsulex.l"
++#line 955 "wcsulex.l"
  {
  	  add(&factor, types, &expon, scale, units);
  	  bracket = !bracket;
-@@ -8736,7 +8733,7 @@ YY_RULE_SETUP
+@@ -8736,7 +8722,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 118:
  YY_RULE_SETUP
 -#line 972 "wcsulex.l"
-+#line 969 "wcsulex.l"
++#line 961 "wcsulex.l"
  {
  	  status = wcserr_set(WCSERR_SET(UNITSERR_BAD_EXPON_SYMBOL),
  	    "Invalid symbol in EXPON context in '%s'", unitstr);
-@@ -8745,9 +8742,9 @@ YY_RULE_SETUP
+@@ -8745,9 +8731,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 119:
  YY_RULE_SETUP
 -#line 978 "wcsulex.l"
-+#line 975 "wcsulex.l"
++#line 967 "wcsulex.l"
  {
 -	  /* Discard any remaining input. */
 +	  // Discard any remaining input.
  	}
  	YY_BREAK
  case YY_STATE_EOF(INITIAL):
-@@ -8756,9 +8753,9 @@ case YY_STATE_EOF(PREFIX):
+@@ -8756,9 +8742,9 @@ case YY_STATE_EOF(PREFIX):
  case YY_STATE_EOF(UNITS):
  case YY_STATE_EOF(EXPON):
  case YY_STATE_EOF(FLUSH):
 -#line 982 "wcsulex.l"
-+#line 979 "wcsulex.l"
++#line 971 "wcsulex.l"
  {
 -	  /* End-of-string. */
 +	  // End-of-string.
  	  if (YY_START == EXPON) {
  	    add(&factor, types, &expon, scale, units);
  	  }
-@@ -8793,10 +8790,10 @@ case YY_STATE_EOF(FLUSH):
+@@ -8782,7 +8768,7 @@ case YY_STATE_EOF(FLUSH):
+ 	  }
+ 	
+ 	  if (status) {
+-	    for (i = 0; i < WCSUNITS_NTYPE; i++) {
++	    for (int i = 0; i < WCSUNITS_NTYPE; i++) {
+ 	      units[i] = 0.0;
+ 	      *scale = 0.0;
+ 	    }
+@@ -8793,10 +8779,10 @@ case YY_STATE_EOF(FLUSH):
  	YY_BREAK
  case 120:
  YY_RULE_SETUP
 -#line 1016 "wcsulex.l"
-+#line 1013 "wcsulex.l"
++#line 1005 "wcsulex.l"
  ECHO;
  	YY_BREAK
 -#line 8800 "wcsulex.c"
-+#line 8797 "wcsulex.c"
++#line 8786 "wcsulex.c"
  
  	case YY_END_OF_BUFFER:
  		{
-@@ -9961,7 +9958,7 @@ void yyfree (void * ptr , yyscan_t yysca
+@@ -9961,7 +9947,35 @@ void yyfree (void * ptr , yyscan_t yysca
  
  #define YYTABLES_NAME "yytables"
  
 -#line 1016 "wcsulex.l"
-+#line 1013 "wcsulex.l"
++#line 1005 "wcsulex.l"
++
++
++/*----------------------------------------------------------------------------
++* External interface to the scanner.
++*---------------------------------------------------------------------------*/
++
++int wcsulexe(
++  const char unitstr[],
++  int *func,
++  double *scale,
++  double units[WCSUNITS_NTYPE],
++  struct wcserr **err)
++
++{
++  static const char *function = "wcsulexe";
++
++  // Function prototypes.
++  int yylex_init_extra(YY_EXTRA_TYPE extra, yyscan_t *yyscanner);
++  int yylex_destroy(yyscan_t yyscanner);
++
++  struct wcsulex_extra extra;
++  yyscan_t yyscanner;
++  yylex_init_extra(&extra, &yyscanner);
++  int status = wcsulexe_scanner(unitstr, func, scale, units, err, yyscanner);
++  yylex_destroy(yyscanner);
++
++  return status;
++}
  
  
  /*----------------------------------------------------------------------------
-Index: astropy-4.2/cextern/wcslib/C/flexed/wcsutrn.c
+@@ -9976,11 +9990,9 @@ void add(
+   double units[])
+ 
+ {
+-  int i;
+-
+   *scale *= pow(*factor, *expon);
+ 
+-  for (i = 0; i < WCSUNITS_NTYPE; i++) {
++  for (int i = 0; i < WCSUNITS_NTYPE; i++) {
+     units[i] += *expon * types[i];
+     types[i] = 0.0;
+   }
+Index: astropy-4.2.1/cextern/wcslib/C/flexed/wcsutrn.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/flexed/wcsutrn.c
-+++ astropy-4.2/cextern/wcslib/C/flexed/wcsutrn.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/flexed/wcsutrn.c
++++ astropy-4.2.1/cextern/wcslib/C/flexed/wcsutrn.c
 @@ -724,7 +724,7 @@ static const flex_int16_t yy_nxt[][128]
         43,  -10,  -10,  -10,  -10,  -10,  -10,   43,   43,   43,
  
@@ -14654,7 +16250,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsutrn.c
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -14668,7 +16264,7 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsutrn.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcsutrn.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcsutrn.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcsutrn.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
  * wcsutrn.l is a Flex description file containing the definition of a lexical
@@ -14677,25 +16273,43 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsutrn.c
  /* Exclusive start states. */
  
 -#line 51 "wcsutrn.l"
-+#line 48 "wcsutrn.l"
++#line 49 "wcsutrn.l"
  #include <setjmp.h>
  #include <stdio.h>
  #include <stdlib.h>
-@@ -4292,7 +4430,7 @@ static const yy_state_type yy_NUL_trans[
- static int wcsutrne_scanner(int ctrl, char unitstr[], struct wcserr **err,
-                             yyscan_t yyscanner);
+@@ -4289,43 +4427,26 @@ static const yy_state_type yy_NUL_trans[
+ #include "wcserr.h"
+ #include "wcsunits.h"
  
+-static int wcsutrne_scanner(int ctrl, char unitstr[], struct wcserr **err,
+-                            yyscan_t yyscanner);
+-
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
- 
- int wcsutrne(
-   int ctrl,
-@@ -4312,20 +4450,20 @@ int wcsutrne(
-   return status;
- }
- 
+-
+-int wcsutrne(
+-  int ctrl,
+-  char unitstr[],
+-  struct wcserr **err)
+-
+-{
+-  int status;
+-  yyscan_t yyscanner;
+-  int yylex_init(yyscan_t *yyscanner);
+-  int yylex_destroy(yyscan_t yyscanner);
+-
+-  yylex_init(&yyscanner);
+-  status = wcsutrne_scanner(ctrl, unitstr, err, yyscanner);
+-  yylex_destroy(yyscanner);
+-
+-  return status;
+-}
+-
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
++// User data associated with yyscanner.
++struct wcsutrn_extra {
++  // Used in preempting the call to exit() by yy_fatal_error().
++  jmp_buf abort_jmp_env;
++};
  
  #define YY_DECL int wcsutrne_scanner(int ctrl, char unitstr[], \
   struct wcserr **err, yyscan_t yyscanner)
@@ -14705,53 +16319,88 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsutrn.c
  #define YY_INPUT(inbuff, count, bufsize) { count = YY_NULL; }
  
 -/* Used in preempting the call to exit() by yy_fatal_error(). */
-+// Used in preempting the call to exit() by yy_fatal_error().
- jmp_buf wcsutrn_abort_jmp_env;
- #define exit(status) longjmp(wcsutrn_abort_jmp_env, status)
+-jmp_buf wcsutrn_abort_jmp_env;
+-#define exit(status) longjmp(wcsutrn_abort_jmp_env, status)
++// Preempt the call to exit() by yy_fatal_error().
++#define exit(status) longjmp(yyextra->abort_jmp_env, status);
++
++// Internal helper functions.
++static YY_DECL;
  
 -#line 4328 "wcsutrn.c"
 -#line 4329 "wcsutrn.c"
-+#line 4466 "wcsutrn.c"
-+#line 4467 "wcsutrn.c"
++#line 4449 "wcsutrn.c"
++#line 4450 "wcsutrn.c"
  
  #define INITIAL 0
  #define NEXT 1
-@@ -4574,9 +4712,9 @@ YY_DECL
+@@ -4339,9 +4460,7 @@ jmp_buf wcsutrn_abort_jmp_env;
+ #include <unistd.h>
+ #endif
+ 
+-#ifndef YY_EXTRA_TYPE
+-#define YY_EXTRA_TYPE void *
+-#endif
++#define YY_EXTRA_TYPE struct wcsutrn_extra *
+ 
+ /* Holds the entire state of the reentrant scanner. */
+ struct yyguts_t
+@@ -4574,29 +4693,29 @@ YY_DECL
  		}
  
  	{
 -#line 96 "wcsutrn.l"
-+#line 93 "wcsutrn.l"
++#line 77 "wcsutrn.l"
  
 -#line 98 "wcsutrn.l"
-+#line 95 "wcsutrn.l"
- 	static const char *function = "wcsutrne";
+-	static const char *function = "wcsutrne";
+-	
+-	char orig[80], subs[80];
+-	int bracket = 0;
+-	int unsafe  = 0;
+-	int status  = -1;
++#line 79 "wcsutrn.l"
++	static const char *function = "wcsutrne_scanner";
  	
- 	char orig[80], subs[80];
-@@ -4593,7 +4731,7 @@ YY_DECL
+ 	if (err) *err = 0x0;
+ 	
++	char orig[80], subs[80];
+ 	*orig = '\0';
+ 	*subs = '\0';
+ 	
++	int bracket = 0;
++	int unsafe  = 0;
++	int status  = -1;
++	
+ 	yy_delete_buffer(YY_CURRENT_BUFFER, yyscanner);
  	yy_scan_string(unitstr, yyscanner);
  	*unitstr = '\0';
  	
 -	/* Return here via longjmp() invoked by yy_fatal_error(). */
+-	if (setjmp(wcsutrn_abort_jmp_env)) {
 +	// Return here via longjmp() invoked by yy_fatal_error().
- 	if (setjmp(wcsutrn_abort_jmp_env)) {
++	if (setjmp(yyextra->abort_jmp_env)) {
  	  return wcserr_set(WCSERR_SET(UNITSERR_PARSER_ERROR),
- 	    "Internal units translator error parsing '%s'", unitstr);
-@@ -4605,7 +4743,7 @@ YY_DECL
+-	    "Internal units translator error parsing '%s'", unitstr);
++	    "Internal units translator error");
+ 	}
+ 	
+ 	BEGIN(INITIAL);
+@@ -4605,7 +4724,7 @@ YY_DECL
  	fprintf(stderr, "\n%s ->\n", unitstr);
  #endif
  
 -#line 4609 "wcsutrn.c"
-+#line 4747 "wcsutrn.c"
++#line 4728 "wcsutrn.c"
  
  	while ( /*CONSTCOND*/1 )		/* loops until end-of-file is reached */
  		{
-@@ -4638,24 +4776,24 @@ do_action:	/* This label is used only to
+@@ -4638,24 +4757,24 @@ do_action:	/* This label is used only to
  	{ /* beginning of action switch */
  case 1:
  YY_RULE_SETUP
 -#line 126 "wcsutrn.l"
-+#line 123 "wcsutrn.l"
++#line 107 "wcsutrn.l"
  {
 -	  /* Looks like a keycomment. */
 +	  // Looks like a keycomment.
@@ -14763,293 +16412,293 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsutrn.c
  YY_RULE_SETUP
 -#line 132 "wcsutrn.l"
 -/* Discard leading whitespace. */
-+#line 129 "wcsutrn.l"
++#line 113 "wcsutrn.l"
 +// Discard leading whitespace.
  	YY_BREAK
  case 3:
  /* rule 3 can match eol */
  YY_RULE_SETUP
 -#line 134 "wcsutrn.l"
-+#line 131 "wcsutrn.l"
++#line 115 "wcsutrn.l"
  {
 -	  /* Non-alphabetic character. */
 +	  // Non-alphabetic character.
  	  strcat(unitstr, yytext);
  	  if (bracket && *yytext == ']') {
  	    BEGIN(FLUSH);
-@@ -4664,7 +4802,7 @@ YY_RULE_SETUP
+@@ -4664,7 +4783,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 4:
  YY_RULE_SETUP
 -#line 142 "wcsutrn.l"
-+#line 139 "wcsutrn.l"
++#line 123 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "Angstrom");
-@@ -4673,7 +4811,7 @@ YY_RULE_SETUP
+@@ -4673,7 +4792,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 5:
  YY_RULE_SETUP
 -#line 148 "wcsutrn.l"
-+#line 145 "wcsutrn.l"
++#line 129 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "arcmin");
-@@ -4682,7 +4820,7 @@ YY_RULE_SETUP
+@@ -4682,7 +4801,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 6:
  YY_RULE_SETUP
 -#line 154 "wcsutrn.l"
-+#line 151 "wcsutrn.l"
++#line 135 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "arcsec");
-@@ -4691,7 +4829,7 @@ YY_RULE_SETUP
+@@ -4691,7 +4810,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 7:
  YY_RULE_SETUP
 -#line 160 "wcsutrn.l"
-+#line 157 "wcsutrn.l"
++#line 141 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "beam");
-@@ -4700,7 +4838,7 @@ YY_RULE_SETUP
+@@ -4700,7 +4819,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 8:
  YY_RULE_SETUP
 -#line 166 "wcsutrn.l"
-+#line 163 "wcsutrn.l"
++#line 147 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "byte");
-@@ -4709,7 +4847,7 @@ YY_RULE_SETUP
+@@ -4709,7 +4828,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 9:
  YY_RULE_SETUP
 -#line 172 "wcsutrn.l"
-+#line 169 "wcsutrn.l"
++#line 153 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "d");
-@@ -4718,7 +4856,7 @@ YY_RULE_SETUP
+@@ -4718,7 +4837,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 10:
  YY_RULE_SETUP
 -#line 178 "wcsutrn.l"
-+#line 175 "wcsutrn.l"
++#line 159 "wcsutrn.l"
  {
  	  unsafe = 1;
  	  strcpy(orig, yytext);
-@@ -4728,7 +4866,7 @@ YY_RULE_SETUP
+@@ -4728,7 +4847,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 11:
  YY_RULE_SETUP
 -#line 185 "wcsutrn.l"
-+#line 182 "wcsutrn.l"
++#line 166 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "deg");
-@@ -4737,7 +4875,7 @@ YY_RULE_SETUP
+@@ -4737,7 +4856,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 12:
  YY_RULE_SETUP
 -#line 191 "wcsutrn.l"
-+#line 188 "wcsutrn.l"
++#line 172 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "GHz");
-@@ -4746,7 +4884,7 @@ YY_RULE_SETUP
+@@ -4746,7 +4865,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 13:
  YY_RULE_SETUP
 -#line 197 "wcsutrn.l"
-+#line 194 "wcsutrn.l"
++#line 178 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "h");
-@@ -4755,7 +4893,7 @@ YY_RULE_SETUP
+@@ -4755,7 +4874,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 14:
  YY_RULE_SETUP
 -#line 203 "wcsutrn.l"
-+#line 200 "wcsutrn.l"
++#line 184 "wcsutrn.l"
  {
  	  unsafe = 1;
  	  strcpy(orig, yytext);
-@@ -4765,7 +4903,7 @@ YY_RULE_SETUP
+@@ -4765,7 +4884,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 15:
  YY_RULE_SETUP
 -#line 210 "wcsutrn.l"
-+#line 207 "wcsutrn.l"
++#line 191 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "Hz");
-@@ -4774,7 +4912,7 @@ YY_RULE_SETUP
+@@ -4774,7 +4893,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 16:
  YY_RULE_SETUP
 -#line 216 "wcsutrn.l"
-+#line 213 "wcsutrn.l"
++#line 197 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "kHz");
-@@ -4783,7 +4921,7 @@ YY_RULE_SETUP
+@@ -4783,7 +4902,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 17:
  YY_RULE_SETUP
 -#line 222 "wcsutrn.l"
-+#line 219 "wcsutrn.l"
++#line 203 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "Jy");
-@@ -4792,7 +4930,7 @@ YY_RULE_SETUP
+@@ -4792,7 +4911,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 18:
  YY_RULE_SETUP
 -#line 228 "wcsutrn.l"
-+#line 225 "wcsutrn.l"
++#line 209 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "K");
-@@ -4801,7 +4939,7 @@ YY_RULE_SETUP
+@@ -4801,7 +4920,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 19:
  YY_RULE_SETUP
 -#line 234 "wcsutrn.l"
-+#line 231 "wcsutrn.l"
++#line 215 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "km");
-@@ -4810,7 +4948,7 @@ YY_RULE_SETUP
+@@ -4810,7 +4929,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 20:
  YY_RULE_SETUP
 -#line 240 "wcsutrn.l"
-+#line 237 "wcsutrn.l"
++#line 221 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "m");
-@@ -4819,7 +4957,7 @@ YY_RULE_SETUP
+@@ -4819,7 +4938,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 21:
  YY_RULE_SETUP
 -#line 246 "wcsutrn.l"
-+#line 243 "wcsutrn.l"
++#line 227 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "min");
-@@ -4828,7 +4966,7 @@ YY_RULE_SETUP
+@@ -4828,7 +4947,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 22:
  YY_RULE_SETUP
 -#line 252 "wcsutrn.l"
-+#line 249 "wcsutrn.l"
++#line 233 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "MHz");
-@@ -4837,7 +4975,7 @@ YY_RULE_SETUP
+@@ -4837,7 +4956,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 23:
  YY_RULE_SETUP
 -#line 258 "wcsutrn.l"
-+#line 255 "wcsutrn.l"
++#line 239 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "ohm");
-@@ -4846,7 +4984,7 @@ YY_RULE_SETUP
+@@ -4846,7 +4965,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 24:
  YY_RULE_SETUP
 -#line 264 "wcsutrn.l"
-+#line 261 "wcsutrn.l"
++#line 245 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "Pa");
-@@ -4855,7 +4993,7 @@ YY_RULE_SETUP
+@@ -4855,7 +4974,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 25:
  YY_RULE_SETUP
 -#line 270 "wcsutrn.l"
-+#line 267 "wcsutrn.l"
++#line 251 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "pixel");
-@@ -4864,7 +5002,7 @@ YY_RULE_SETUP
+@@ -4864,7 +4983,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 26:
  YY_RULE_SETUP
 -#line 276 "wcsutrn.l"
-+#line 273 "wcsutrn.l"
++#line 257 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "rad");
-@@ -4873,7 +5011,7 @@ YY_RULE_SETUP
+@@ -4873,7 +4992,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 27:
  YY_RULE_SETUP
 -#line 282 "wcsutrn.l"
-+#line 279 "wcsutrn.l"
++#line 263 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "s");
-@@ -4882,7 +5020,7 @@ YY_RULE_SETUP
+@@ -4882,7 +5001,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 28:
  YY_RULE_SETUP
 -#line 288 "wcsutrn.l"
-+#line 285 "wcsutrn.l"
++#line 269 "wcsutrn.l"
  {
  	  unsafe = 1;
  	  strcpy(orig, yytext);
-@@ -4892,7 +5030,7 @@ YY_RULE_SETUP
+@@ -4892,7 +5011,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 29:
  YY_RULE_SETUP
 -#line 295 "wcsutrn.l"
-+#line 292 "wcsutrn.l"
++#line 276 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "V");
-@@ -4901,7 +5039,7 @@ YY_RULE_SETUP
+@@ -4901,7 +5020,7 @@ YY_RULE_SETUP
  	YY_BREAK
  case 30:
  YY_RULE_SETUP
 -#line 301 "wcsutrn.l"
-+#line 298 "wcsutrn.l"
++#line 282 "wcsutrn.l"
  {
  	  strcpy(orig, yytext);
  	  strcpy(subs, "yr");
-@@ -4910,9 +5048,9 @@ YY_RULE_SETUP
+@@ -4910,9 +5029,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 31:
  YY_RULE_SETUP
 -#line 307 "wcsutrn.l"
-+#line 304 "wcsutrn.l"
++#line 288 "wcsutrn.l"
  {
 -	  /* Not a recognized alias. */
 +	  // Not a recognized alias.
  	  strcpy(orig, yytext);
  	  strcpy(subs, orig);
  	  BEGIN(NEXT);
-@@ -4920,9 +5058,9 @@ YY_RULE_SETUP
+@@ -4920,9 +5039,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 32:
  YY_RULE_SETUP
 -#line 314 "wcsutrn.l"
-+#line 311 "wcsutrn.l"
++#line 295 "wcsutrn.l"
  {
 -	  /* Reject the alias match. */
 +	  // Reject the alias match.
  	  strcat(orig, yytext);
  	  strcpy(subs, orig);
  	}
-@@ -4930,17 +5068,17 @@ YY_RULE_SETUP
+@@ -4930,17 +5049,17 @@ YY_RULE_SETUP
  case 33:
  /* rule 33 can match eol */
  YY_RULE_SETUP
 -#line 320 "wcsutrn.l"
-+#line 317 "wcsutrn.l"
++#line 301 "wcsutrn.l"
  {
 -	  /* Discard separating whitespace. */
 +	  // Discard separating whitespace.
@@ -15059,31 +16708,31 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsutrn.c
  case 34:
  YY_RULE_SETUP
 -#line 325 "wcsutrn.l"
-+#line 322 "wcsutrn.l"
++#line 306 "wcsutrn.l"
  {
 -	  /* Compress separating whitespace. */
 +	  // Compress separating whitespace.
  	  strcat(unitstr, subs);
  	  strcat(unitstr, " ");
  	  if (strcmp(orig, subs)) status = 0;
-@@ -4951,9 +5089,9 @@ YY_RULE_SETUP
+@@ -4951,9 +5070,9 @@ YY_RULE_SETUP
  	YY_BREAK
  case 35:
  YY_RULE_SETUP
 -#line 335 "wcsutrn.l"
-+#line 332 "wcsutrn.l"
++#line 316 "wcsutrn.l"
  {
 -	  /* Copy anything else unchanged. */
 +	  // Copy anything else unchanged.
  	  strcat(unitstr, subs);
  	  if (strcmp(orig, subs)) status = 0;
  	  unput(*yytext);
-@@ -4963,18 +5101,18 @@ YY_RULE_SETUP
+@@ -4963,18 +5082,18 @@ YY_RULE_SETUP
  	YY_BREAK
  case 36:
  YY_RULE_SETUP
 -#line 344 "wcsutrn.l"
-+#line 341 "wcsutrn.l"
++#line 325 "wcsutrn.l"
  {
 -	  /* Copy out remaining input. */
 +	  // Copy out remaining input.
@@ -15094,44 +16743,69 @@ Index: astropy-4.2/cextern/wcslib/C/flexed/wcsutrn.c
  case YY_STATE_EOF(NEXT):
  case YY_STATE_EOF(FLUSH):
 -#line 349 "wcsutrn.l"
-+#line 346 "wcsutrn.l"
++#line 330 "wcsutrn.l"
  {
 -	  /* End-of-string. */
 +	  // End-of-string.
  	  if (*subs) {
  	    strcat(unitstr, subs);
  	    if (strcmp(orig, subs)) status = 0;
-@@ -4989,10 +5127,10 @@ case YY_STATE_EOF(FLUSH):
+@@ -4989,10 +5108,10 @@ case YY_STATE_EOF(FLUSH):
  	YY_BREAK
  case 37:
  YY_RULE_SETUP
 -#line 363 "wcsutrn.l"
-+#line 360 "wcsutrn.l"
++#line 344 "wcsutrn.l"
  ECHO;
  	YY_BREAK
 -#line 4996 "wcsutrn.c"
-+#line 5134 "wcsutrn.c"
++#line 5115 "wcsutrn.c"
  
  	case YY_END_OF_BUFFER:
  		{
-@@ -6142,6 +6280,6 @@ void yyfree (void * ptr , yyscan_t yysca
+@@ -6142,6 +6261,31 @@ void yyfree (void * ptr , yyscan_t yysca
  
  #define YYTABLES_NAME "yytables"
  
 -#line 363 "wcsutrn.l"
-+#line 360 "wcsutrn.l"
++#line 344 "wcsutrn.l"
++
  
++/*----------------------------------------------------------------------------
++* External interface to the scanner.
++*---------------------------------------------------------------------------*/
++
++int wcsutrne(
++  int ctrl,
++  char unitstr[],
++  struct wcserr **err)
++
++{
++  static const char *function = "wcsutrne";
++
++  // Function prototypes.
++  int yylex_init_extra(YY_EXTRA_TYPE extra, yyscan_t *yyscanner);
++  int yylex_destroy(yyscan_t yyscanner);
++
++  struct wcsutrn_extra extra;
++  yyscan_t yyscanner;
++  yylex_init_extra(&extra, &yyscanner);
++  int status = wcsutrne_scanner(ctrl, unitstr, err, yyscanner);
++  yylex_destroy(yyscanner);
++
++  return status;
++}
  
-Index: astropy-4.2/cextern/wcslib/C/getwcstab.c
+Index: astropy-4.2.1/cextern/wcslib/C/getwcstab.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/getwcstab.c
-+++ astropy-4.2/cextern/wcslib/C/getwcstab.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/getwcstab.c
++++ astropy-4.2.1/cextern/wcslib/C/getwcstab.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -15145,7 +16819,7 @@ Index: astropy-4.2/cextern/wcslib/C/getwcstab.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: getwcstab.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: getwcstab.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: getwcstab.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <stdlib.h>
@@ -15253,16 +16927,16 @@ Index: astropy-4.2/cextern/wcslib/C/getwcstab.c
    if (naxes) free(naxes);
    if (*status) {
      wtbp = wtb;
-Index: astropy-4.2/cextern/wcslib/C/getwcstab.h
+Index: astropy-4.2.1/cextern/wcslib/C/getwcstab.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/getwcstab.h
-+++ astropy-4.2/cextern/wcslib/C/getwcstab.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/getwcstab.h
++++ astropy-4.2.1/cextern/wcslib/C/getwcstab.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -15276,11 +16950,11 @@ Index: astropy-4.2/cextern/wcslib/C/getwcstab.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: getwcstab.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: getwcstab.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: getwcstab.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
@@ -15416,21 +17090,21 @@ Index: astropy-4.2/cextern/wcslib/C/getwcstab.h
  
 -#endif /* WCSLIB_GETWCSTAB */
 +#endif // WCSLIB_GETWCSTAB
-Index: astropy-4.2/cextern/wcslib/C/lin.c
+Index: astropy-4.2.1/cextern/wcslib/C/lin.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/lin.c
-+++ astropy-4.2/cextern/wcslib/C/lin.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/lin.c
++++ astropy-4.2.1/cextern/wcslib/C/lin.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
  
-@@ -18,11 +17,9 @@
+@@ -18,17 +17,15 @@
    You should have received a copy of the GNU Lesser General Public License
    along with WCSLIB.  If not, see http://www.gnu.org/licenses.
  
@@ -15439,10 +17113,17 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: lin.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: lin.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: lin.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
++#include <math.h>
  #include <stdio.h>
+ #include <stdlib.h>
+ #include <string.h>
+-#include <math.h>
+ 
+ #include "wcserr.h"
+ #include "wcsprintf.h"
 @@ -37,7 +34,7 @@
  
  const int LINSET = 137;
@@ -15649,16 +17330,74 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
      if (lin->piximg) free(lin->piximg);
      if (lin->imgpix) free(lin->imgpix);
      if (lin->tmpcrd) free(lin->tmpcrd);
-@@ -443,7 +440,7 @@ int linfree(struct linprm *lin)
+@@ -443,7 +440,65 @@ int linfree(struct linprm *lin)
    return 0;
  }
  
 -/*--------------------------------------------------------------------------*/
++//----------------------------------------------------------------------------
++
++int linsize(const struct linprm *lin, int sizes[2])
++
++{
++
++  if (lin == 0x0) {
++    sizes[0] = sizes[1] = 0;
++    return LINERR_SUCCESS;
++  }
++
++  // Base size, in bytes.
++  sizes[0] = sizeof(struct linprm);
++
++  // Total size of allocated memory, in bytes.
++  sizes[1] = 0;
++
++  int exsizes[2];
++  int naxis = lin->naxis;
++
++  // linprm::crpix[].
++  sizes[1] += naxis * sizeof(double);
++
++  // linprm::pc[].
++  sizes[1] += naxis*naxis * sizeof(double);
++
++  // linprm::cdelt[].
++  sizes[1] += naxis * sizeof(double);
++
++  // linprm::dispre[].
++  dissize(lin->dispre, exsizes);
++  sizes[2] += exsizes[0] + exsizes[1];
++
++  // linprm::disseq[].
++  dissize(lin->disseq, exsizes);
++  sizes[2] += exsizes[0] + exsizes[1];
++
++  // linprm::err[].
++  wcserr_size(lin->err, exsizes);
++  sizes[1] += exsizes[0] + exsizes[1];
++
++  // The remaining arrays are allocated unconditionally by linset().
++  if (lin->flag != LINSET) {
++    return LINERR_SUCCESS;
++  }
++
++  // linprm::piximg[].
++  sizes[1] += naxis*naxis * sizeof(double);
++
++  // linprm::imgpix[].
++  sizes[1] += naxis*naxis * sizeof(double);
++
++  // linprm::tmpcrd[].
++  sizes[1] += naxis * sizeof(double);
++
++  return LINERR_SUCCESS;
++}
++
 +//----------------------------------------------------------------------------
  
  int linprt(const struct linprm *lin)
  
-@@ -458,7 +455,7 @@ int linprt(const struct linprm *lin)
+@@ -458,7 +513,7 @@ int linprt(const struct linprm *lin)
    }
    wcsprintf("       flag: %d\n", lin->flag);
  
@@ -15667,7 +17406,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    wcsprintf("      naxis: %d\n", lin->naxis);
  
    WCSPRINTF_PTR("      crpix: ", lin->crpix, "\n");
-@@ -492,7 +489,7 @@ int linprt(const struct linprm *lin)
+@@ -492,7 +547,7 @@ int linprt(const struct linprm *lin)
    if (lin->disseq != 0x0) wcsprintf("  (see below)");
    wcsprintf("\n");
  
@@ -15676,7 +17415,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    if (lin->piximg == 0x0) {
      wcsprintf("     piximg: (nil)\n");
    } else {
-@@ -524,16 +521,16 @@ int linprt(const struct linprm *lin)
+@@ -524,16 +579,16 @@ int linprt(const struct linprm *lin)
    wcsprintf("     affine: %d\n", lin->affine);
    wcsprintf("     simple: %d\n", lin->simple);
  
@@ -15696,7 +17435,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    wcsprintf("     m_flag: %d\n", lin->m_flag);
    wcsprintf("    m_naxis: %d\n", lin->m_naxis);
    WCSPRINTF_PTR("    m_crpix: ", lin->m_crpix, "");
-@@ -552,7 +549,7 @@ int linprt(const struct linprm *lin)
+@@ -552,7 +607,7 @@ int linprt(const struct linprm *lin)
    if (lin->disseq && lin->m_disseq == lin->disseq) wcsprintf("  (= disseq)");
    wcsprintf("\n");
  
@@ -15705,7 +17444,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    if (lin->dispre) {
      wcsprintf("\n");
      wcsprintf("dispre.*\n");
-@@ -568,7 +565,7 @@ int linprt(const struct linprm *lin)
+@@ -568,7 +623,7 @@ int linprt(const struct linprm *lin)
    return 0;
  }
  
@@ -15714,7 +17453,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
  
  int linperr(const struct linprm *lin, const char *prefix)
  
-@@ -583,7 +580,7 @@ int linperr(const struct linprm *lin, co
+@@ -583,7 +638,7 @@ int linperr(const struct linprm *lin, co
    return 0;
  }
  
@@ -15723,7 +17462,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
  
  int linset(struct linprm *lin)
  
-@@ -599,7 +596,7 @@ int linset(struct linprm *lin)
+@@ -599,7 +654,7 @@ int linset(struct linprm *lin)
  
    naxis = lin->naxis;
  
@@ -15732,7 +17471,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    lin->unity = 1;
    pc = lin->pc;
    for (i = 0; i < naxis; i++) {
-@@ -621,7 +618,7 @@ int linset(struct linprm *lin)
+@@ -621,7 +676,7 @@ int linset(struct linprm *lin)
  
    if (lin->unity) {
      if (lin->flag == LINSET) {
@@ -15741,7 +17480,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
        if (lin->piximg) free(lin->piximg);
        if (lin->imgpix) free(lin->imgpix);
      }
-@@ -630,7 +627,7 @@ int linset(struct linprm *lin)
+@@ -630,7 +685,7 @@ int linset(struct linprm *lin)
      lin->imgpix  = 0x0;
      lin->i_naxis = 0;
  
@@ -15750,7 +17489,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
      for (i = 0; i < naxis; i++) {
        if (lin->cdelt[i] == 0.0) {
          return wcserr_set(LIN_ERRMSG(LINERR_SINGULAR_MTX));
-@@ -640,12 +637,12 @@ int linset(struct linprm *lin)
+@@ -640,12 +695,12 @@ int linset(struct linprm *lin)
    } else {
      if (lin->flag != LINSET || lin->i_naxis < naxis) {
        if (lin->flag == LINSET) {
@@ -15765,7 +17504,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
        if ((lin->piximg = calloc(naxis*naxis, sizeof(double))) == 0x0) {
          return wcserr_set(LIN_ERRMSG(LINERR_MEMORY));
        }
-@@ -658,28 +655,30 @@ int linset(struct linprm *lin)
+@@ -658,28 +713,30 @@ int linset(struct linprm *lin)
        lin->i_naxis = naxis;
      }
  
@@ -15803,7 +17542,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    lin->affine = 1;
    if (lin->dispre) {
      if ((status = disset(lin->dispre))) {
-@@ -700,7 +699,7 @@ int linset(struct linprm *lin)
+@@ -700,7 +757,7 @@ int linset(struct linprm *lin)
    lin->simple = lin->unity && lin->affine;
  
  
@@ -15812,7 +17551,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    if (lin->tmpcrd) free(lin->tmpcrd);
    if ((lin->tmpcrd = calloc(naxis, sizeof(double))) == 0x0) {
      linfree(lin);
-@@ -713,7 +712,7 @@ int linset(struct linprm *lin)
+@@ -713,7 +770,7 @@ int linset(struct linprm *lin)
    return 0;
  }
  
@@ -15821,7 +17560,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
  
  int linp2x(
    struct linprm *lin,
-@@ -732,7 +731,7 @@ int linp2x(
+@@ -732,7 +789,7 @@ int linp2x(
    struct wcserr **err;
  
  
@@ -15830,7 +17569,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    if (lin == 0x0) return LINERR_NULL_POINTER;
    err = &(lin->err);
  
-@@ -743,12 +742,12 @@ int linp2x(
+@@ -743,12 +800,12 @@ int linp2x(
    n = lin->naxis;
  
  
@@ -15845,7 +17584,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
      nelemn = nelem - n;
      for (k = 0; k < ncoord; k++) {
        for (i = 0; i < n; i++) {
-@@ -760,17 +759,17 @@ int linp2x(
+@@ -760,17 +817,17 @@ int linp2x(
      }
  
    } else if (lin->affine) {
@@ -15866,7 +17605,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
          temp = *(pix++) - lin->crpix[j];
          for (i = 0; i < n; i++, piximg += n) {
            img[i] += *piximg * temp;
-@@ -782,7 +781,7 @@ int linp2x(
+@@ -782,7 +839,7 @@ int linp2x(
      }
  
    } else {
@@ -15875,7 +17614,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
      ndbl = n * sizeof(double);
      tmp  = lin->tmpcrd;
  
-@@ -819,13 +818,13 @@ int linp2x(
+@@ -819,13 +876,13 @@ int linp2x(
            return wcserr_set(LIN_ERRMSG(lin_diserr[status]));
          }
  
@@ -15891,7 +17630,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
          for (i = 0; i < n; i++) {
            img[i] *= lin->cdelt[i];
          }
-@@ -839,7 +838,7 @@ int linp2x(
+@@ -839,7 +896,7 @@ int linp2x(
    return 0;
  }
  
@@ -15900,7 +17639,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
  
  int linx2p(
    struct linprm *lin,
-@@ -857,7 +856,7 @@ int linx2p(
+@@ -857,7 +914,7 @@ int linx2p(
    struct wcserr **err;
  
  
@@ -15909,7 +17648,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    if (lin == 0x0) return LINERR_NULL_POINTER;
    err = &(lin->err);
  
-@@ -868,12 +867,12 @@ int linx2p(
+@@ -868,12 +925,12 @@ int linx2p(
    n = lin->naxis;
  
  
@@ -15924,7 +17663,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
      nelemn = nelem - n;
      for (k = 0; k < ncoord; k++) {
        for (j = 0; j < n; j++) {
-@@ -885,10 +884,10 @@ int linx2p(
+@@ -885,10 +942,10 @@ int linx2p(
      }
  
    } else if (lin->affine) {
@@ -15937,7 +17676,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
        imgpix = lin->imgpix;
  
        for (j = 0; j < n; j++) {
-@@ -906,13 +905,13 @@ int linx2p(
+@@ -906,13 +963,13 @@ int linx2p(
      }
  
    } else {
@@ -15953,7 +17692,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
          for (i = 0; i < n; i++) {
            tmp[i] = img[i] / lin->cdelt[i];
          }
-@@ -924,13 +923,13 @@ int linx2p(
+@@ -924,13 +981,13 @@ int linx2p(
          memcpy(tmp, pix, ndbl);
  
        } else if (lin->unity) {
@@ -15969,7 +17708,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
          memcpy(tmp, img, ndbl);
        }
  
-@@ -965,7 +964,7 @@ int linx2p(
+@@ -965,7 +1022,7 @@ int linx2p(
    return 0;
  }
  
@@ -15978,7 +17717,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
  
  int linwarp(
    struct linprm *lin,
-@@ -990,7 +989,7 @@ int linwarp(
+@@ -990,7 +1047,7 @@ int linwarp(
    struct wcserr **err;
  
  
@@ -15987,7 +17726,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    if (lin == 0x0) return LINERR_NULL_POINTER;
    err = &(lin->err);
  
-@@ -1006,17 +1005,17 @@ int linwarp(
+@@ -1006,17 +1063,17 @@ int linwarp(
    if (avgtot) *avgtot = 0.0;
    if (rmstot) *rmstot = 0.0;
  
@@ -16008,7 +17747,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    affine.flag = -1;
    if ((status = (lincpy(1, lin, &affine) ||
                   lindist(1, &affine, 0x0, 0) ||
-@@ -1025,7 +1024,7 @@ int linwarp(
+@@ -1025,7 +1082,7 @@ int linwarp(
      return wcserr_set(LIN_ERRMSG(status));
    }
  
@@ -16017,7 +17756,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    pixinc = lin->tmpcrd;
    ncoord = 0;
    for (j = 0; j < naxis; j++) {
-@@ -1044,12 +1043,12 @@ int linwarp(
+@@ -1044,12 +1101,12 @@ int linwarp(
      }
  
      if (j == 0) {
@@ -16032,7 +17771,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    if ((pix0 = calloc((3*ncoord+4)*naxis, sizeof(double))) == 0x0) {
      return wcserr_set(LIN_ERRMSG(LINERR_MEMORY));
    }
-@@ -1062,10 +1061,10 @@ int linwarp(
+@@ -1062,10 +1119,10 @@ int linwarp(
    ssqdis = sumdis + naxis;
  
  
@@ -16045,7 +17784,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    for (j = 0; j < naxis; j++) {
      pix0[j] = pixblc ? pixblc[j] : 1.0;
      pixend[j] = pixtrc[j] + 0.5*pixinc[j];
-@@ -1080,7 +1079,7 @@ int linwarp(
+@@ -1080,7 +1137,7 @@ int linwarp(
      }
    }
  
@@ -16054,7 +17793,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    for (j = 0; j < naxis; j++) {
      sumdis[j] = 0.0;
      ssqdis[j] = 0.0;
-@@ -1089,20 +1088,20 @@ int linwarp(
+@@ -1089,20 +1146,20 @@ int linwarp(
    ssqtot = 0.0;
  
  
@@ -16079,7 +17818,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
      pix0p = pix0;
      pix1p = pix1;
      for (i = 0; i < ncoord; i++) {
-@@ -1128,7 +1127,7 @@ int linwarp(
+@@ -1128,7 +1185,7 @@ int linwarp(
        if (maxtot && *maxtot < totdis) *maxtot = totdis;
      }
  
@@ -16088,7 +17827,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
      for (j = 1; j < naxis; j++) {
        pix0[j] += pixinc[j];
        if ((carry = (pix0[j] > pixend[j]))) {
-@@ -1146,7 +1145,7 @@ int linwarp(
+@@ -1146,7 +1203,7 @@ int linwarp(
    }
  
  
@@ -16097,7 +17836,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    for (j = 0; j < naxis; j++) {
      ssqdis[j] /= *nsamp;
      sumdis[j] /= *nsamp;
-@@ -1167,7 +1166,7 @@ cleanup:
+@@ -1167,7 +1224,7 @@ cleanup:
    return status;
  }
  
@@ -16106,7 +17845,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
  
  int matinv(int n, const double mat[], double inv[])
  
-@@ -1177,7 +1176,7 @@ int matinv(int n, const double mat[], do
+@@ -1177,7 +1234,7 @@ int matinv(int n, const double mat[], do
    double colmax, *lu, *rowmax, dtemp;
  
  
@@ -16115,7 +17854,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    if ((mxl = calloc(n, sizeof(int))) == 0x0) {
      return LINERR_MEMORY;
    }
-@@ -1200,9 +1199,9 @@ int matinv(int n, const double mat[], do
+@@ -1200,9 +1257,9 @@ int matinv(int n, const double mat[], do
    }
  
  
@@ -16127,7 +17866,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
      mxl[i] = i;
  
      rowmax[i] = 0.0;
-@@ -1214,7 +1213,7 @@ int matinv(int n, const double mat[], do
+@@ -1214,7 +1271,7 @@ int matinv(int n, const double mat[], do
        lu[ij] = mat[ij];
      }
  
@@ -16136,7 +17875,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
      if (rowmax[i] == 0.0) {
        free(mxl);
        free(lxm);
-@@ -1225,9 +1224,9 @@ int matinv(int n, const double mat[], do
+@@ -1225,9 +1282,9 @@ int matinv(int n, const double mat[], do
    }
  
  
@@ -16148,7 +17887,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
      colmax = fabs(lu[k*n+k]) / rowmax[k];
      pivot = k;
  
-@@ -1241,34 +1240,34 @@ int matinv(int n, const double mat[], do
+@@ -1241,34 +1298,34 @@ int matinv(int n, const double mat[], do
      }
  
      if (pivot > k) {
@@ -16190,7 +17929,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
          for (j = k+1; j < n; j++) {
            lu[i*n+j] -= lu[ik]*lu[k*n+j];
          }
-@@ -1277,14 +1276,14 @@ int matinv(int n, const double mat[], do
+@@ -1277,14 +1334,14 @@ int matinv(int n, const double mat[], do
    }
  
  
@@ -16208,7 +17947,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
    for (i = 0, ij = 0; i < n; i++) {
      for (j = 0; j < n; j++, ij++) {
        inv[ij] = 0.0;
-@@ -1294,14 +1293,14 @@ int matinv(int n, const double mat[], do
+@@ -1294,14 +1351,14 @@ int matinv(int n, const double mat[], do
    for (k = 0; k < n; k++) {
      inv[lxm[k]*n+k] = 1.0;
  
@@ -16225,16 +17964,16 @@ Index: astropy-4.2/cextern/wcslib/C/lin.c
      for (i = n-1; i >= 0; i--) {
        for (j = i+1; j < n; j++) {
          inv[i*n+k] -= lu[i*n+j]*inv[j*n+k];
-Index: astropy-4.2/cextern/wcslib/C/lin.h
+Index: astropy-4.2.1/cextern/wcslib/C/lin.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/lin.h
-+++ astropy-4.2/cextern/wcslib/C/lin.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/lin.h
++++ astropy-4.2.1/cextern/wcslib/C/lin.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -16248,15 +17987,62 @@ Index: astropy-4.2/cextern/wcslib/C/lin.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: lin.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: lin.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: lin.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
-@@ -619,44 +616,44 @@ extern "C" {
+@@ -44,8 +41,8 @@
+ * like a C++ class but with no encapsulation.
+ *
+ * Six routines, linini(), lininit(), lindis(), lindist() lincpy(), and
+-* linfree() are provided to manage the linprm struct, and another, linprt(),
+-* prints its contents.
++* linfree() are provided to manage the linprm struct, linsize() computes its
++* total size including allocated memory, and linprt() prints its contents.
+ *
+ * linperr() prints the error message(s) (if any) stored in a linprm struct,
+ * and the disprm structs that it may contain.
+@@ -225,6 +222,35 @@
+ *                         1: Null linprm pointer passed.
+ *
+ *
++* linsize() - Compute the size of a linprm struct
++* -----------------------------------------------
++* linsize() computes the full size of a linprm struct, including allocated
++* memory.
++*
++* Given:
++*   lin       const struct linprm*
++*                       Linear transformation parameters.
++*
++*                       If NULL, the base size of the struct and the allocated
++*                       size are both set to zero.
++*
++* Returned:
++*   sizes     int[2]    The first element is the base size of the struct as
++*                       returned by sizeof(struct linprm).  The second element
++*                       is the total allocated size, in bytes, assuming that
++*                       the allocation was done by linini().  This figure
++*                       includes memory allocated for members of constituent
++*                       structs, such as linprm::dispre.
++*
++*                       It is not an error for the struct not to have been set
++*                       up via linset(), which normally results in additional
++*                       memory allocation.
++*
++* Function return value:
++*             int       Status return value:
++*                         0: Success.
++*
++*
+ * linprt() - Print routine for the linprm struct
+ * ----------------------------------------------
+ * linprt() prints the contents of a linprm struct using wcsprintf().  Mainly
+@@ -619,44 +645,44 @@ extern "C" {
  extern const char *lin_errmsg[];
  
  enum lin_errmsg_enum {
@@ -16333,7 +18119,7 @@ Index: astropy-4.2/cextern/wcslib/C/lin.h
    double *tmpcrd;
  
    int    m_flag, m_naxis;
-@@ -664,7 +661,7 @@ struct linprm {
+@@ -664,7 +690,7 @@ struct linprm {
    struct disprm *m_dispre, *m_disseq;
  };
  
@@ -16342,7 +18128,16 @@ Index: astropy-4.2/cextern/wcslib/C/lin.h
  #define LINLEN (sizeof(struct linprm)/sizeof(int))
  
  
-@@ -701,7 +698,7 @@ int linwarp(struct linprm *lin, const do
+@@ -680,6 +706,8 @@ int lincpy(int alloc, const struct linpr
+ 
+ int linfree(struct linprm *lin);
+ 
++int linsize(const struct linprm *lin, int sizes[2]);
++
+ int linprt(const struct linprm *lin);
+ 
+ int linperr(const struct linprm *lin, const char *prefix);
+@@ -701,7 +729,7 @@ int linwarp(struct linprm *lin, const do
  int matinv(int n, const double mat[], double inv[]);
  
  
@@ -16351,22 +18146,22 @@ Index: astropy-4.2/cextern/wcslib/C/lin.h
  #define linini_errmsg lin_errmsg
  #define lincpy_errmsg lin_errmsg
  #define linfree_errmsg lin_errmsg
-@@ -714,4 +711,4 @@ int matinv(int n, const double mat[], do
+@@ -714,4 +742,4 @@ int matinv(int n, const double mat[], do
  }
  #endif
  
 -#endif /* WCSLIB_LIN */
 +#endif // WCSLIB_LIN
-Index: astropy-4.2/cextern/wcslib/C/log.c
+Index: astropy-4.2.1/cextern/wcslib/C/log.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/log.c
-+++ astropy-4.2/cextern/wcslib/C/log.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/log.c
++++ astropy-4.2.1/cextern/wcslib/C/log.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -16380,7 +18175,7 @@ Index: astropy-4.2/cextern/wcslib/C/log.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: log.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: log.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: log.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <math.h>
@@ -16410,16 +18205,16 @@ Index: astropy-4.2/cextern/wcslib/C/log.c
  
  int logs2x(
    double crval,
-Index: astropy-4.2/cextern/wcslib/C/log.h
+Index: astropy-4.2.1/cextern/wcslib/C/log.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/log.h
-+++ astropy-4.2/cextern/wcslib/C/log.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/log.h
++++ astropy-4.2.1/cextern/wcslib/C/log.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -16433,11 +18228,11 @@ Index: astropy-4.2/cextern/wcslib/C/log.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: log.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: log.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: log.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
@@ -16468,16 +18263,16 @@ Index: astropy-4.2/cextern/wcslib/C/log.h
  
 -#endif /* WCSLIB_LOG */
 +#endif // WCSLIB_LOG
-Index: astropy-4.2/cextern/wcslib/C/prj.c
+Index: astropy-4.2.1/cextern/wcslib/C/prj.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/prj.c
-+++ astropy-4.2/cextern/wcslib/C/prj.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/prj.c
++++ astropy-4.2.1/cextern/wcslib/C/prj.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -16491,7 +18286,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: prj.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: prj.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: prj.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <math.h>
@@ -16531,7 +18326,16 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  #define PRJERR_BAD_PARAM_SET(function) \
    wcserr_set(&(prj->err), PRJERR_BAD_PARAM, function, __FILE__, __LINE__, \
      "Invalid parameters for %s projection", prj->name);
-@@ -184,7 +181,7 @@ int prjini(struct prjprm *prj)
+@@ -124,6 +121,8 @@ const char *prj_errmsg[] = {
+ * prjfree frees any memory that may have been allocated to store an error
+ *        message in the prjprm struct.
+ *
++* prjsize computed the size of a prjprm struct.
++*
+ * prjprt prints the contents of a prjprm struct.
+ *
+ * prjbchk performs bounds checking on the native coordinates returned by the
+@@ -184,7 +183,7 @@ int prjini(struct prjprm *prj)
    return 0;
  }
  
@@ -16540,16 +18344,41 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int prjfree(struct prjprm *prj)
  
-@@ -196,7 +193,7 @@ int prjfree(struct prjprm *prj)
+@@ -196,7 +195,32 @@ int prjfree(struct prjprm *prj)
    return 0;
  }
  
 -/*--------------------------------------------------------------------------*/
++//----------------------------------------------------------------------------
++
++int prjsize(const struct prjprm *prj, int sizes[2])
++
++{
++  if (prj == 0x0) {
++    sizes[0] = sizes[1] = 0;
++    return PRJERR_SUCCESS;
++  }
++
++  // Base size, in bytes.
++  sizes[0] = sizeof(struct prjprm);
++
++  // Total size of allocated memory, in bytes.
++  sizes[1] = 0;
++
++  int exsizes[2];
++
++  // prjprm::err.
++  wcserr_size(prj->err, exsizes);
++  sizes[1] += exsizes[0] + exsizes[1];
++
++  return PRJERR_SUCCESS;
++}
++
 +//----------------------------------------------------------------------------
  
  int prjprt(const struct prjprm *prj)
  
-@@ -284,7 +281,7 @@ int prjprt(const struct prjprm *prj)
+@@ -284,7 +308,7 @@ int prjprt(const struct prjprm *prj)
    return 0;
  }
  
@@ -16558,7 +18387,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int prjperr(const struct prjprm *prj, const char *prefix)
  
-@@ -298,7 +295,7 @@ int prjperr(const struct prjprm *prj, co
+@@ -298,7 +322,7 @@ int prjperr(const struct prjprm *prj, co
    return 0;
  }
  
@@ -16567,7 +18396,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int prjbchk(
    double tol,
-@@ -319,7 +316,7 @@ int prjbchk(
+@@ -319,7 +343,7 @@ int prjbchk(
    statp  = stat;
    for (itheta = 0; itheta < ntheta; itheta++) {
      for (iphi = 0; iphi < nphi; iphi++, phip += spt, thetap += spt, statp++) {
@@ -16576,7 +18405,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        if (*statp == 0) {
          if (*phip < -180.0) {
            if (*phip < -180.0-tol) {
-@@ -359,7 +356,7 @@ int prjbchk(
+@@ -359,7 +383,7 @@ int prjbchk(
    return status;
  }
  
@@ -16585,7 +18414,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int prjset(struct prjprm *prj)
  
-@@ -372,7 +369,7 @@ int prjset(struct prjprm *prj)
+@@ -372,7 +396,7 @@ int prjset(struct prjprm *prj)
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    err = &(prj->err);
  
@@ -16594,7 +18423,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    prj->code[3] = '\0';
    if (strcmp(prj->code, "AZP") == 0) {
      status = azpset(prj);
-@@ -431,7 +428,7 @@ int prjset(struct prjprm *prj)
+@@ -431,7 +455,7 @@ int prjset(struct prjprm *prj)
    } else if (strcmp(prj->code, "XPH") == 0) {
      status = xphset(prj);
    } else {
@@ -16603,7 +18432,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
      status = wcserr_set(WCSERR_SET(PRJERR_BAD_PARAM),
                 "Unrecognized projection code '%s'", prj->code);
    }
-@@ -439,7 +436,7 @@ int prjset(struct prjprm *prj)
+@@ -439,7 +463,7 @@ int prjset(struct prjprm *prj)
    return status;
  }
  
@@ -16612,7 +18441,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int prjx2s(
    struct prjprm *prj,
-@@ -456,7 +453,7 @@ int prjx2s(
+@@ -456,7 +480,7 @@ int prjx2s(
  {
    int status;
  
@@ -16621,7 +18450,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag == 0) {
      if ((status = prjset(prj))) return status;
-@@ -465,7 +462,7 @@ int prjx2s(
+@@ -465,7 +489,7 @@ int prjx2s(
    return prj->prjx2s(prj, nx, ny, sxy, spt, x, y, phi, theta, stat);
  }
  
@@ -16630,7 +18459,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int prjs2x(
    struct prjprm *prj,
-@@ -482,7 +479,7 @@ int prjs2x(
+@@ -482,7 +506,7 @@ int prjs2x(
  {
    int status;
  
@@ -16639,7 +18468,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag == 0) {
      if ((status = prjset(prj))) return status;
-@@ -511,7 +508,7 @@ int prjoff(
+@@ -511,7 +535,7 @@ int prjoff(
    prj->y0 = 0.0;
  
    if (undefined(prj->phi0) || undefined(prj->theta0)) {
@@ -16648,7 +18477,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
      prj->phi0   = phi0;
      prj->theta0 = theta0;
  
-@@ -607,7 +604,7 @@ int azpset(struct prjprm *prj)
+@@ -607,7 +631,7 @@ int azpset(struct prjprm *prj)
    return prjoff(prj, 0.0, 90.0);
  }
  
@@ -16657,7 +18486,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int azpx2s(
    struct prjprm *prj,
-@@ -630,7 +627,7 @@ int azpx2s(
+@@ -630,7 +654,7 @@ int azpx2s(
    register double *phip, *thetap;
  
  
@@ -16666,7 +18495,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != AZP) {
      if ((status = azpset(prj))) return status;
-@@ -648,7 +645,7 @@ int azpx2s(
+@@ -648,7 +672,7 @@ int azpx2s(
    status = 0;
  
  
@@ -16675,7 +18504,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -663,7 +660,7 @@ int azpx2s(
+@@ -663,7 +687,7 @@ int azpx2s(
    }
  
  
@@ -16684,7 +18513,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -718,7 +715,7 @@ int azpx2s(
+@@ -718,7 +742,7 @@ int azpx2s(
    }
  
  
@@ -16693,7 +18522,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("azpx2s");
    }
-@@ -726,7 +723,7 @@ int azpx2s(
+@@ -726,7 +750,7 @@ int azpx2s(
    return status;
  }
  
@@ -16702,7 +18531,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int azps2x(
    struct prjprm *prj,
-@@ -748,7 +745,7 @@ int azps2x(
+@@ -748,7 +772,7 @@ int azps2x(
    register double *xp, *yp;
  
  
@@ -16711,7 +18540,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != AZP) {
      if ((status = azpset(prj))) return status;
-@@ -766,7 +763,7 @@ int azps2x(
+@@ -766,7 +790,7 @@ int azps2x(
    status = 0;
  
  
@@ -16720,7 +18549,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -784,7 +781,7 @@ int azps2x(
+@@ -784,7 +808,7 @@ int azps2x(
    }
  
  
@@ -16729,7 +18558,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -805,16 +802,16 @@ int azps2x(
+@@ -805,16 +829,16 @@ int azps2x(
        } else {
          r = prj->w[0]*costhe/t;
  
@@ -16749,7 +18578,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
              t = prj->pv[1] / sqrt(1.0 + s*s);
  
              if (fabs(t) <= 1.0) {
-@@ -926,7 +923,7 @@ int szpset(struct prjprm *prj)
+@@ -926,7 +950,7 @@ int szpset(struct prjprm *prj)
    return prjoff(prj, 0.0, 90.0);
  }
  
@@ -16758,7 +18587,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int szpx2s(
    struct prjprm *prj,
-@@ -949,7 +946,7 @@ int szpx2s(
+@@ -949,7 +973,7 @@ int szpx2s(
    register double *phip, *thetap;
  
  
@@ -16767,7 +18596,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != SZP) {
      if ((status = szpset(prj))) return status;
-@@ -967,7 +964,7 @@ int szpx2s(
+@@ -967,7 +991,7 @@ int szpx2s(
    status = 0;
  
  
@@ -16776,7 +18605,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -982,7 +979,7 @@ int szpx2s(
+@@ -982,7 +1006,7 @@ int szpx2s(
    }
  
  
@@ -16785,7 +18614,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -999,7 +996,7 @@ int szpx2s(
+@@ -999,7 +1023,7 @@ int szpx2s(
        xy = xr*x1 + yr*y1;
  
        if (r2 < 1.0e-10) {
@@ -16794,7 +18623,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          z = r2/2.0;
          *thetap = 90.0 - R2D*sqrt(r2/(1.0 + xy));
  
-@@ -1010,7 +1007,7 @@ int szpx2s(
+@@ -1010,7 +1034,7 @@ int szpx2s(
          c = r2 - xy - xy + t - 1.0;
          d = b*b - a*c;
  
@@ -16803,7 +18632,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          if (d < 0.0) {
            *phip = 0.0;
            *thetap = 0.0;
-@@ -1020,7 +1017,7 @@ int szpx2s(
+@@ -1020,7 +1044,7 @@ int szpx2s(
          }
          d = sqrt(d);
  
@@ -16812,7 +18641,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          sinth1 = (-b + d)/a;
          sinth2 = (-b - d)/a;
          sinthe = (sinth1 > sinth2) ? sinth1 : sinth2;
-@@ -1057,7 +1054,7 @@ int szpx2s(
+@@ -1057,7 +1081,7 @@ int szpx2s(
    }
  
  
@@ -16821,7 +18650,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("szpx2s");
    }
-@@ -1065,7 +1062,7 @@ int szpx2s(
+@@ -1065,7 +1089,7 @@ int szpx2s(
    return status;
  }
  
@@ -16830,7 +18659,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int szps2x(
    struct prjprm *prj,
-@@ -1087,7 +1084,7 @@ int szps2x(
+@@ -1087,7 +1111,7 @@ int szps2x(
    register double *xp, *yp;
  
  
@@ -16839,7 +18668,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != SZP) {
      if ((status = szpset(prj))) return status;
-@@ -1105,7 +1102,7 @@ int szps2x(
+@@ -1105,7 +1129,7 @@ int szps2x(
    status = 0;
  
  
@@ -16848,7 +18677,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -1123,7 +1120,7 @@ int szps2x(
+@@ -1123,7 +1147,7 @@ int szps2x(
    }
  
  
@@ -16857,7 +18686,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -1147,16 +1144,16 @@ int szps2x(
+@@ -1147,16 +1171,16 @@ int szps2x(
        v = prj->w[5]*s/t + prj->y0;
  
        for (iphi = 0; iphi < mphi; iphi++, xp += sxy, yp += sxy) {
@@ -16877,7 +18706,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
              s = prj->w[1]*(*xp) - prj->w[2]*(*yp);
              t = 1.0/sqrt(prj->w[7] + s*s);
  
-@@ -1230,7 +1227,7 @@ int tanset(struct prjprm *prj)
+@@ -1230,7 +1254,7 @@ int tanset(struct prjprm *prj)
    return prjoff(prj, 0.0, 90.0);
  }
  
@@ -16886,7 +18715,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int tanx2s(
    struct prjprm *prj,
-@@ -1252,7 +1249,7 @@ int tanx2s(
+@@ -1252,7 +1276,7 @@ int tanx2s(
    register double *phip, *thetap;
  
  
@@ -16895,7 +18724,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != TAN) {
      if ((status = tanset(prj))) return status;
-@@ -1270,7 +1267,7 @@ int tanx2s(
+@@ -1270,7 +1294,7 @@ int tanx2s(
    status = 0;
  
  
@@ -16904,7 +18733,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -1285,7 +1282,7 @@ int tanx2s(
+@@ -1285,7 +1309,7 @@ int tanx2s(
    }
  
  
@@ -16913,7 +18742,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -1310,7 +1307,7 @@ int tanx2s(
+@@ -1310,7 +1334,7 @@ int tanx2s(
    }
  
  
@@ -16922,7 +18751,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("tanx2s");
    }
-@@ -1318,7 +1315,7 @@ int tanx2s(
+@@ -1318,7 +1342,7 @@ int tanx2s(
    return status;
  }
  
@@ -16931,7 +18760,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int tans2x(
    struct prjprm *prj,
-@@ -1340,7 +1337,7 @@ int tans2x(
+@@ -1340,7 +1364,7 @@ int tans2x(
    register double *xp, *yp;
  
  
@@ -16940,7 +18769,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != TAN) {
      if ((status = tanset(prj))) return status;
-@@ -1358,7 +1355,7 @@ int tans2x(
+@@ -1358,7 +1382,7 @@ int tans2x(
    status = 0;
  
  
@@ -16949,7 +18778,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -1376,7 +1373,7 @@ int tans2x(
+@@ -1376,7 +1400,7 @@ int tans2x(
    }
  
  
@@ -16958,7 +18787,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -1394,7 +1391,7 @@ int tans2x(
+@@ -1394,7 +1418,7 @@ int tans2x(
      } else {
        r =  prj->r0*cosd(*thetap)/s;
  
@@ -16967,7 +18796,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        istat = 0;
        if (prj->bounds&1) {
          if (s < 0.0) {
-@@ -1465,7 +1462,7 @@ int stgset(struct prjprm *prj)
+@@ -1465,7 +1489,7 @@ int stgset(struct prjprm *prj)
    return prjoff(prj, 0.0, 90.0);
  }
  
@@ -16976,7 +18805,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int stgx2s(
    struct prjprm *prj,
-@@ -1487,7 +1484,7 @@ int stgx2s(
+@@ -1487,7 +1511,7 @@ int stgx2s(
    register double *phip, *thetap;
  
  
@@ -16985,7 +18814,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != STG) {
      if ((status = stgset(prj))) return status;
-@@ -1503,7 +1500,7 @@ int stgx2s(
+@@ -1503,7 +1527,7 @@ int stgx2s(
    }
  
  
@@ -16994,7 +18823,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -1518,7 +1515,7 @@ int stgx2s(
+@@ -1518,7 +1542,7 @@ int stgx2s(
    }
  
  
@@ -17003,7 +18832,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -1545,7 +1542,7 @@ int stgx2s(
+@@ -1545,7 +1569,7 @@ int stgx2s(
    return 0;
  }
  
@@ -17012,7 +18841,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int stgs2x(
    struct prjprm *prj,
-@@ -1567,7 +1564,7 @@ int stgs2x(
+@@ -1567,7 +1591,7 @@ int stgs2x(
    register double *xp, *yp;
  
  
@@ -17021,7 +18850,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != STG) {
      if ((status = stgset(prj))) return status;
-@@ -1585,7 +1582,7 @@ int stgs2x(
+@@ -1585,7 +1609,7 @@ int stgs2x(
    status = 0;
  
  
@@ -17030,7 +18859,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -1603,7 +1600,7 @@ int stgs2x(
+@@ -1603,7 +1627,7 @@ int stgs2x(
    }
  
  
@@ -17039,7 +18868,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -1688,7 +1685,7 @@ int sinset(struct prjprm *prj)
+@@ -1688,7 +1712,7 @@ int sinset(struct prjprm *prj)
    return prjoff(prj, 0.0, 90.0);
  }
  
@@ -17048,7 +18877,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int sinx2s(
    struct prjprm *prj,
-@@ -1712,7 +1709,7 @@ int sinx2s(
+@@ -1712,7 +1736,7 @@ int sinx2s(
    register double *phip, *thetap;
  
  
@@ -17057,7 +18886,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != SIN) {
      if ((status = sinset(prj))) return status;
-@@ -1733,7 +1730,7 @@ int sinx2s(
+@@ -1733,7 +1757,7 @@ int sinx2s(
    status = 0;
  
  
@@ -17066,7 +18895,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -1748,7 +1745,7 @@ int sinx2s(
+@@ -1748,7 +1772,7 @@ int sinx2s(
    }
  
  
@@ -17075,7 +18904,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -1758,12 +1755,12 @@ int sinx2s(
+@@ -1758,12 +1782,12 @@ int sinx2s(
      y02 = y0*y0;
  
      for (ix = 0; ix < mx; ix++, phip += spt, thetap += spt) {
@@ -17090,7 +18919,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          if (r2 != 0.0) {
            *phip = atan2d(x0, -y0);
          } else {
-@@ -1781,11 +1778,11 @@ int sinx2s(
+@@ -1781,11 +1805,11 @@ int sinx2s(
          }
  
        } else {
@@ -17104,7 +18933,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
            z = r2/2.0;
            *thetap = 90.0 - R2D*sqrt(r2/(1.0 + xy));
  
-@@ -1795,7 +1792,7 @@ int sinx2s(
+@@ -1795,7 +1819,7 @@ int sinx2s(
            c = r2 - xy - xy + prj->w[3];
            d = b*b - a*c;
  
@@ -17113,7 +18942,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
            if (d < 0.0) {
              *phip = 0.0;
              *thetap = 0.0;
-@@ -1805,7 +1802,7 @@ int sinx2s(
+@@ -1805,7 +1829,7 @@ int sinx2s(
            }
            d = sqrt(d);
  
@@ -17122,7 +18951,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
            sinth1 = (-b + d)/a;
            sinth2 = (-b - d)/a;
            sinthe = (sinth1 > sinth2) ? sinth1 : sinth2;
-@@ -1849,7 +1846,7 @@ int sinx2s(
+@@ -1849,7 +1873,7 @@ int sinx2s(
    }
  
  
@@ -17131,7 +18960,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("sinx2s");
    }
-@@ -1857,7 +1854,7 @@ int sinx2s(
+@@ -1857,7 +1881,7 @@ int sinx2s(
    return status;
  }
  
@@ -17140,7 +18969,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int sins2x(
    struct prjprm *prj,
-@@ -1879,7 +1876,7 @@ int sins2x(
+@@ -1879,7 +1903,7 @@ int sins2x(
    register double *xp, *yp;
  
  
@@ -17149,7 +18978,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != SIN) {
      if ((status = sinset(prj))) return status;
-@@ -1897,7 +1894,7 @@ int sins2x(
+@@ -1897,7 +1921,7 @@ int sins2x(
    status = 0;
  
  
@@ -17158,7 +18987,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -1915,7 +1912,7 @@ int sins2x(
+@@ -1915,7 +1939,7 @@ int sins2x(
    }
  
  
@@ -17167,7 +18996,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -1936,7 +1933,7 @@ int sins2x(
+@@ -1936,7 +1960,7 @@ int sins2x(
      r = prj->r0*costhe;
  
      if (prj->w[1] == 0.0) {
@@ -17176,7 +19005,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        istat = 0;
        if (prj->bounds&1) {
          if (*thetap < 0.0) {
-@@ -1952,7 +1949,7 @@ int sins2x(
+@@ -1952,7 +1976,7 @@ int sins2x(
        }
  
      } else {
@@ -17185,7 +19014,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        z *= prj->r0;
        z1 = prj->pv[1]*z - prj->x0;
        z2 = prj->pv[2]*z - prj->y0;
-@@ -2028,7 +2025,7 @@ int arcset(struct prjprm *prj)
+@@ -2028,7 +2052,7 @@ int arcset(struct prjprm *prj)
    return prjoff(prj, 0.0, 90.0);
  }
  
@@ -17194,7 +19023,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int arcx2s(
    struct prjprm *prj,
-@@ -2050,7 +2047,7 @@ int arcx2s(
+@@ -2050,7 +2074,7 @@ int arcx2s(
    register double *phip, *thetap;
  
  
@@ -17203,7 +19032,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != ARC) {
      if ((status = arcset(prj))) return status;
-@@ -2068,7 +2065,7 @@ int arcx2s(
+@@ -2068,7 +2092,7 @@ int arcx2s(
    status = 0;
  
  
@@ -17212,7 +19041,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -2083,7 +2080,7 @@ int arcx2s(
+@@ -2083,7 +2107,7 @@ int arcx2s(
    }
  
  
@@ -17221,7 +19050,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -2109,7 +2106,7 @@ int arcx2s(
+@@ -2109,7 +2133,7 @@ int arcx2s(
    }
  
  
@@ -17230,7 +19059,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("arcx2s");
    }
-@@ -2117,7 +2114,7 @@ int arcx2s(
+@@ -2117,7 +2141,7 @@ int arcx2s(
    return status;
  }
  
@@ -17239,7 +19068,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int arcs2x(
    struct prjprm *prj,
-@@ -2139,7 +2136,7 @@ int arcs2x(
+@@ -2139,7 +2163,7 @@ int arcs2x(
    register double *xp, *yp;
  
  
@@ -17248,7 +19077,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != ARC) {
      if ((status = arcset(prj))) return status;
-@@ -2155,7 +2152,7 @@ int arcs2x(
+@@ -2155,7 +2179,7 @@ int arcs2x(
    }
  
  
@@ -17257,7 +19086,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -2173,7 +2170,7 @@ int arcs2x(
+@@ -2173,7 +2197,7 @@ int arcs2x(
    }
  
  
@@ -17266,7 +19095,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -2240,7 +2237,7 @@ int zpnset(struct prjprm *prj)
+@@ -2240,7 +2264,7 @@ int zpnset(struct prjprm *prj)
    prj->global    = 0;
    prj->divergent = 0;
  
@@ -17275,7 +19104,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    for (k = PVN-1; k >= 0 && prj->pv[k] == 0.0; k--);
    if (k < 0) {
      return PRJERR_BAD_PARAM_SET("zpnset");
-@@ -2249,18 +2246,18 @@ int zpnset(struct prjprm *prj)
+@@ -2249,18 +2273,18 @@ int zpnset(struct prjprm *prj)
    prj->n = k;
  
    if (k < 2) {
@@ -17297,7 +19126,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
      for (j = 0; j < 180; j++) {
        zd2 = j*D2R;
        d2  = 0.0;
-@@ -2274,11 +2271,11 @@ int zpnset(struct prjprm *prj)
+@@ -2274,11 +2298,11 @@ int zpnset(struct prjprm *prj)
      }
  
      if (j == 180) {
@@ -17311,7 +19140,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        for (j = 1; j <= 10; j++) {
          zd = zd1 - d1*(zd2-zd1)/(d2-d1);
  
-@@ -2313,7 +2310,7 @@ int zpnset(struct prjprm *prj)
+@@ -2313,7 +2337,7 @@ int zpnset(struct prjprm *prj)
    return prjoff(prj, 0.0, 90.0);
  }
  
@@ -17320,7 +19149,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int zpnx2s(
    struct prjprm *prj,
-@@ -2336,7 +2333,7 @@ int zpnx2s(
+@@ -2336,7 +2360,7 @@ int zpnx2s(
    register double *phip, *thetap;
  
  
@@ -17329,7 +19158,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != ZPN) {
      if ((status = zpnset(prj))) return status;
-@@ -2356,7 +2353,7 @@ int zpnx2s(
+@@ -2356,7 +2380,7 @@ int zpnx2s(
    status = 0;
  
  
@@ -17338,7 +19167,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -2371,7 +2368,7 @@ int zpnx2s(
+@@ -2371,7 +2395,7 @@ int zpnx2s(
    }
  
  
@@ -17347,7 +19176,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -2391,15 +2388,15 @@ int zpnx2s(
+@@ -2391,15 +2415,15 @@ int zpnx2s(
        }
  
        if (k < 1) {
@@ -17366,7 +19195,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          a = prj->pv[2];
          b = prj->pv[1];
          c = prj->pv[0] - r;
-@@ -2413,7 +2410,7 @@ int zpnx2s(
+@@ -2413,7 +2437,7 @@ int zpnx2s(
          }
          d = sqrt(d);
  
@@ -17375,7 +19204,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          zd1 = (-b + d)/(2.0*a);
          zd2 = (-b - d)/(2.0*a);
          zd  = (zd1<zd2) ? zd1 : zd2;
-@@ -2436,7 +2433,7 @@ int zpnx2s(
+@@ -2436,7 +2460,7 @@ int zpnx2s(
            zd = PI;
          }
        } else {
@@ -17384,7 +19213,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          zd1 = 0.0;
          r1  = prj->pv[0];
          zd2 = prj->w[0];
-@@ -2459,7 +2456,7 @@ int zpnx2s(
+@@ -2459,7 +2483,7 @@ int zpnx2s(
            }
            zd = zd2;
          } else {
@@ -17393,7 +19222,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
            for (j = 0; j < 100; j++) {
              lambda = (r2 - r)/(r2 - r1);
              if (lambda < 0.1) {
-@@ -2496,7 +2493,7 @@ int zpnx2s(
+@@ -2496,7 +2520,7 @@ int zpnx2s(
    }
  
  
@@ -17402,7 +19231,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("zpnx2s");
    }
-@@ -2504,7 +2501,7 @@ int zpnx2s(
+@@ -2504,7 +2528,7 @@ int zpnx2s(
    return status;
  }
  
@@ -17411,7 +19240,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int zpns2x(
    struct prjprm *prj,
-@@ -2526,7 +2523,7 @@ int zpns2x(
+@@ -2526,7 +2550,7 @@ int zpns2x(
    register double *xp, *yp;
  
  
@@ -17420,7 +19249,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != ZPN) {
      if ((status = zpnset(prj))) return status;
-@@ -2544,7 +2541,7 @@ int zpns2x(
+@@ -2544,7 +2568,7 @@ int zpns2x(
    status = 0;
  
  
@@ -17429,7 +19258,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -2562,7 +2559,7 @@ int zpns2x(
+@@ -2562,7 +2586,7 @@ int zpns2x(
    }
  
  
@@ -17438,7 +19267,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -2576,7 +2573,7 @@ int zpns2x(
+@@ -2576,7 +2600,7 @@ int zpns2x(
      }
      r *= prj->r0;
  
@@ -17447,7 +19276,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
      istat = 0;
      if (prj->bounds&1) {
        if (s > prj->w[0]) {
-@@ -2646,7 +2643,7 @@ int zeaset(struct prjprm *prj)
+@@ -2646,7 +2670,7 @@ int zeaset(struct prjprm *prj)
    return prjoff(prj, 0.0, 90.0);
  }
  
@@ -17456,7 +19285,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int zeax2s(
    struct prjprm *prj,
-@@ -2669,7 +2666,7 @@ int zeax2s(
+@@ -2669,7 +2693,7 @@ int zeax2s(
    register double *phip, *thetap;
  
  
@@ -17465,7 +19294,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != ZEA) {
      if ((status = zeaset(prj))) return status;
-@@ -2687,7 +2684,7 @@ int zeax2s(
+@@ -2687,7 +2711,7 @@ int zeax2s(
    status = 0;
  
  
@@ -17474,7 +19303,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -2702,7 +2699,7 @@ int zeax2s(
+@@ -2702,7 +2726,7 @@ int zeax2s(
    }
  
  
@@ -17483,7 +19312,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -2740,7 +2737,7 @@ int zeax2s(
+@@ -2740,7 +2764,7 @@ int zeax2s(
    }
  
  
@@ -17492,7 +19321,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("zeax2s");
    }
-@@ -2748,7 +2745,7 @@ int zeax2s(
+@@ -2748,7 +2772,7 @@ int zeax2s(
    return status;
  }
  
@@ -17501,7 +19330,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int zeas2x(
    struct prjprm *prj,
-@@ -2770,7 +2767,7 @@ int zeas2x(
+@@ -2770,7 +2794,7 @@ int zeas2x(
    register double *xp, *yp;
  
  
@@ -17510,7 +19339,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != ZEA) {
      if ((status = zeaset(prj))) return status;
-@@ -2786,7 +2783,7 @@ int zeas2x(
+@@ -2786,7 +2810,7 @@ int zeas2x(
    }
  
  
@@ -17519,7 +19348,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -2804,7 +2801,7 @@ int zeas2x(
+@@ -2804,7 +2828,7 @@ int zeas2x(
    }
  
  
@@ -17528,7 +19357,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -2897,7 +2894,7 @@ int airset(struct prjprm *prj)
+@@ -2897,7 +2921,7 @@ int airset(struct prjprm *prj)
    return prjoff(prj, 0.0, 90.0);
  }
  
@@ -17537,7 +19366,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int airx2s(
    struct prjprm *prj,
-@@ -2920,7 +2917,7 @@ int airx2s(
+@@ -2920,7 +2944,7 @@ int airx2s(
    register double *phip, *thetap;
  
  
@@ -17546,7 +19375,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != AIR) {
      if ((status = airset(prj))) return status;
-@@ -2938,7 +2935,7 @@ int airx2s(
+@@ -2938,7 +2962,7 @@ int airx2s(
    status = 0;
  
  
@@ -17555,7 +19384,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -2953,7 +2950,7 @@ int airx2s(
+@@ -2953,7 +2977,7 @@ int airx2s(
    }
  
  
@@ -17564,7 +19393,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -2978,7 +2975,7 @@ int airx2s(
+@@ -2978,7 +3002,7 @@ int airx2s(
        } else if (r < prj->w[5]) {
          xi = r*prj->w[6];
        } else {
@@ -17573,7 +19402,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          x1 = x2 = 1.0;
          r1 = r2 = 0.0;
          for (k = 0; k < 30; k++) {
-@@ -2998,7 +2995,7 @@ int airx2s(
+@@ -2998,7 +3022,7 @@ int airx2s(
          }
  
          for (k = 0; k < 100; k++) {
@@ -17582,7 +19411,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
            lambda = (r2-r)/(r2-r1);
            if (lambda < 0.1) {
              lambda = 0.1;
-@@ -3036,7 +3033,7 @@ int airx2s(
+@@ -3036,7 +3060,7 @@ int airx2s(
    }
  
  
@@ -17591,7 +19420,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("airx2s");
    }
-@@ -3044,7 +3041,7 @@ int airx2s(
+@@ -3044,7 +3068,7 @@ int airx2s(
    return status;
  }
  
@@ -17600,7 +19429,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int airs2x(
    struct prjprm *prj,
-@@ -3066,7 +3063,7 @@ int airs2x(
+@@ -3066,7 +3090,7 @@ int airs2x(
    register double *xp, *yp;
  
  
@@ -17609,7 +19438,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != AIR) {
      if ((status = airset(prj))) return status;
-@@ -3084,7 +3081,7 @@ int airs2x(
+@@ -3084,7 +3108,7 @@ int airs2x(
    status = 0;
  
  
@@ -17618,7 +19447,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -3102,7 +3099,7 @@ int airs2x(
+@@ -3102,7 +3126,7 @@ int airs2x(
    }
  
  
@@ -17627,7 +19456,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -3222,7 +3219,7 @@ int cypset(struct prjprm *prj)
+@@ -3222,7 +3246,7 @@ int cypset(struct prjprm *prj)
    return prjoff(prj, 0.0, 0.0);
  }
  
@@ -17636,7 +19465,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int cypx2s(
    struct prjprm *prj,
-@@ -3244,7 +3241,7 @@ int cypx2s(
+@@ -3244,7 +3268,7 @@ int cypx2s(
    register double *phip, *thetap;
  
  
@@ -17645,7 +19474,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != CYP) {
      if ((status = cypset(prj))) return status;
-@@ -3262,7 +3259,7 @@ int cypx2s(
+@@ -3262,7 +3286,7 @@ int cypx2s(
    status = 0;
  
  
@@ -17654,7 +19483,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -3277,7 +3274,7 @@ int cypx2s(
+@@ -3277,7 +3301,7 @@ int cypx2s(
    }
  
  
@@ -17663,7 +19492,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    thetap = theta;
    statp = stat;
-@@ -3292,7 +3289,7 @@ int cypx2s(
+@@ -3292,7 +3316,7 @@ int cypx2s(
    }
  
  
@@ -17672,7 +19501,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("cypx2s");
    }
-@@ -3300,7 +3297,7 @@ int cypx2s(
+@@ -3300,7 +3324,7 @@ int cypx2s(
    return status;
  }
  
@@ -17681,7 +19510,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int cyps2x(
    struct prjprm *prj,
-@@ -3322,7 +3319,7 @@ int cyps2x(
+@@ -3322,7 +3346,7 @@ int cyps2x(
    register double *xp, *yp;
  
  
@@ -17690,7 +19519,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != CYP) {
      if ((status = cypset(prj))) return status;
-@@ -3340,7 +3337,7 @@ int cyps2x(
+@@ -3340,7 +3364,7 @@ int cyps2x(
    status = 0;
  
  
@@ -17699,7 +19528,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -3355,7 +3352,7 @@ int cyps2x(
+@@ -3355,7 +3379,7 @@ int cyps2x(
    }
  
  
@@ -17708,7 +19537,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    yp = y;
    statp = stat;
-@@ -3450,7 +3447,7 @@ int ceaset(struct prjprm *prj)
+@@ -3450,7 +3474,7 @@ int ceaset(struct prjprm *prj)
    return prjoff(prj, 0.0, 0.0);
  }
  
@@ -17717,7 +19546,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int ceax2s(
    struct prjprm *prj,
-@@ -3473,7 +3470,7 @@ int ceax2s(
+@@ -3473,7 +3497,7 @@ int ceax2s(
    register double *phip, *thetap;
  
  
@@ -17726,7 +19555,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != CEA) {
      if ((status = ceaset(prj))) return status;
-@@ -3491,7 +3488,7 @@ int ceax2s(
+@@ -3491,7 +3515,7 @@ int ceax2s(
    status = 0;
  
  
@@ -17735,7 +19564,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -3506,7 +3503,7 @@ int ceax2s(
+@@ -3506,7 +3530,7 @@ int ceax2s(
    }
  
  
@@ -17744,7 +19573,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    thetap = theta;
    statp = stat;
-@@ -3533,7 +3530,7 @@ int ceax2s(
+@@ -3533,7 +3557,7 @@ int ceax2s(
    }
  
  
@@ -17753,7 +19582,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("ceax2s");
    }
-@@ -3541,7 +3538,7 @@ int ceax2s(
+@@ -3541,7 +3565,7 @@ int ceax2s(
    return status;
  }
  
@@ -17762,7 +19591,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int ceas2x(
    struct prjprm *prj,
-@@ -3563,7 +3560,7 @@ int ceas2x(
+@@ -3563,7 +3587,7 @@ int ceas2x(
    register double *xp, *yp;
  
  
@@ -17771,7 +19600,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != CEA) {
      if ((status = ceaset(prj))) return status;
-@@ -3579,7 +3576,7 @@ int ceas2x(
+@@ -3579,7 +3603,7 @@ int ceas2x(
    }
  
  
@@ -17780,7 +19609,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -3594,7 +3591,7 @@ int ceas2x(
+@@ -3594,7 +3618,7 @@ int ceas2x(
    }
  
  
@@ -17789,7 +19618,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    yp = y;
    statp = stat;
-@@ -3661,7 +3658,7 @@ int carset(struct prjprm *prj)
+@@ -3661,7 +3685,7 @@ int carset(struct prjprm *prj)
    return prjoff(prj, 0.0, 0.0);
  }
  
@@ -17798,7 +19627,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int carx2s(
    struct prjprm *prj,
-@@ -3683,7 +3680,7 @@ int carx2s(
+@@ -3683,7 +3707,7 @@ int carx2s(
    register double *phip, *thetap;
  
  
@@ -17807,7 +19636,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != CAR) {
      if ((status = carset(prj))) return status;
-@@ -3701,7 +3698,7 @@ int carx2s(
+@@ -3701,7 +3725,7 @@ int carx2s(
    status = 0;
  
  
@@ -17816,7 +19645,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -3716,7 +3713,7 @@ int carx2s(
+@@ -3716,7 +3740,7 @@ int carx2s(
    }
  
  
@@ -17825,7 +19654,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    thetap = theta;
    statp = stat;
-@@ -3730,7 +3727,7 @@ int carx2s(
+@@ -3730,7 +3754,7 @@ int carx2s(
    }
  
  
@@ -17834,7 +19663,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("carx2s");
    }
-@@ -3738,7 +3735,7 @@ int carx2s(
+@@ -3738,7 +3762,7 @@ int carx2s(
    return status;
  }
  
@@ -17843,7 +19672,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int cars2x(
    struct prjprm *prj,
-@@ -3760,7 +3757,7 @@ int cars2x(
+@@ -3760,7 +3784,7 @@ int cars2x(
    register double *xp, *yp;
  
  
@@ -17852,7 +19681,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != CAR) {
      if ((status = carset(prj))) return status;
-@@ -3776,7 +3773,7 @@ int cars2x(
+@@ -3776,7 +3800,7 @@ int cars2x(
    }
  
  
@@ -17861,7 +19690,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -3791,7 +3788,7 @@ int cars2x(
+@@ -3791,7 +3815,7 @@ int cars2x(
    }
  
  
@@ -17870,7 +19699,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    yp = y;
    statp = stat;
-@@ -3858,7 +3855,7 @@ int merset(struct prjprm *prj)
+@@ -3858,7 +3882,7 @@ int merset(struct prjprm *prj)
    return prjoff(prj, 0.0, 0.0);
  }
  
@@ -17879,7 +19708,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int merx2s(
    struct prjprm *prj,
-@@ -3880,7 +3877,7 @@ int merx2s(
+@@ -3880,7 +3904,7 @@ int merx2s(
    register double *phip, *thetap;
  
  
@@ -17888,7 +19717,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != MER) {
      if ((status = merset(prj))) return status;
-@@ -3898,7 +3895,7 @@ int merx2s(
+@@ -3898,7 +3922,7 @@ int merx2s(
    status = 0;
  
  
@@ -17897,7 +19726,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -3913,7 +3910,7 @@ int merx2s(
+@@ -3913,7 +3937,7 @@ int merx2s(
    }
  
  
@@ -17906,7 +19735,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    thetap = theta;
    statp  = stat;
-@@ -3927,7 +3924,7 @@ int merx2s(
+@@ -3927,7 +3951,7 @@ int merx2s(
    }
  
  
@@ -17915,7 +19744,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("merx2s");
    }
-@@ -3935,7 +3932,7 @@ int merx2s(
+@@ -3935,7 +3959,7 @@ int merx2s(
    return status;
  }
  
@@ -17924,7 +19753,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int mers2x(
    struct prjprm *prj,
-@@ -3957,7 +3954,7 @@ int mers2x(
+@@ -3957,7 +3981,7 @@ int mers2x(
    register double *xp, *yp;
  
  
@@ -17933,7 +19762,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != MER) {
      if ((status = merset(prj))) return status;
-@@ -3975,7 +3972,7 @@ int mers2x(
+@@ -3975,7 +3999,7 @@ int mers2x(
    status = 0;
  
  
@@ -17942,7 +19771,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -3990,7 +3987,7 @@ int mers2x(
+@@ -3990,7 +4014,7 @@ int mers2x(
    }
  
  
@@ -17951,7 +19780,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    yp = y;
    statp = stat;
-@@ -4065,7 +4062,7 @@ int sflset(struct prjprm *prj)
+@@ -4065,7 +4089,7 @@ int sflset(struct prjprm *prj)
    return prjoff(prj, 0.0, 0.0);
  }
  
@@ -17960,7 +19789,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int sflx2s(
    struct prjprm *prj,
-@@ -4087,7 +4084,7 @@ int sflx2s(
+@@ -4087,7 +4111,7 @@ int sflx2s(
    register double *phip, *thetap;
  
  
@@ -17969,7 +19798,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != SFL) {
      if ((status = sflset(prj))) return status;
-@@ -4105,7 +4102,7 @@ int sflx2s(
+@@ -4105,7 +4129,7 @@ int sflx2s(
    status = 0;
  
  
@@ -17978,7 +19807,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -4120,7 +4117,7 @@ int sflx2s(
+@@ -4120,7 +4144,7 @@ int sflx2s(
    }
  
  
@@ -17987,7 +19816,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -4147,7 +4144,7 @@ int sflx2s(
+@@ -4147,7 +4171,7 @@ int sflx2s(
    }
  
  
@@ -17996,7 +19825,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-12, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("sflx2s");
    }
-@@ -4155,7 +4152,7 @@ int sflx2s(
+@@ -4155,7 +4179,7 @@ int sflx2s(
    return status;
  }
  
@@ -18005,7 +19834,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int sfls2x(
    struct prjprm *prj,
-@@ -4177,7 +4174,7 @@ int sfls2x(
+@@ -4177,7 +4201,7 @@ int sfls2x(
    register double *xp, *yp;
  
  
@@ -18014,7 +19843,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != SFL) {
      if ((status = sflset(prj))) return status;
-@@ -4193,7 +4190,7 @@ int sfls2x(
+@@ -4193,7 +4217,7 @@ int sfls2x(
    }
  
  
@@ -18023,7 +19852,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -4208,7 +4205,7 @@ int sfls2x(
+@@ -4208,7 +4232,7 @@ int sfls2x(
    }
  
  
@@ -18032,7 +19861,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -4284,7 +4281,7 @@ int parset(struct prjprm *prj)
+@@ -4284,7 +4308,7 @@ int parset(struct prjprm *prj)
    return prjoff(prj, 0.0, 0.0);
  }
  
@@ -18041,7 +19870,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int parx2s(
    struct prjprm *prj,
-@@ -4307,7 +4304,7 @@ int parx2s(
+@@ -4307,7 +4331,7 @@ int parx2s(
    register double *phip, *thetap;
  
  
@@ -18050,7 +19879,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != PAR) {
      if ((status = parset(prj))) return status;
-@@ -4325,7 +4322,7 @@ int parx2s(
+@@ -4325,7 +4349,7 @@ int parx2s(
    status = 0;
  
  
@@ -18059,7 +19888,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -4345,7 +4342,7 @@ int parx2s(
+@@ -4345,7 +4369,7 @@ int parx2s(
    }
  
  
@@ -18068,7 +19897,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -4363,7 +4360,7 @@ int parx2s(
+@@ -4363,7 +4387,7 @@ int parx2s(
      } else {
        s = 1.0 - 4.0*r*r;
        if (s == 0.0) {
@@ -18077,7 +19906,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          istat = -1;
        } else {
          s = 1.0/s;
-@@ -4390,7 +4387,7 @@ int parx2s(
+@@ -4390,7 +4414,7 @@ int parx2s(
    }
  
  
@@ -18086,7 +19915,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-12, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("parx2s");
    }
-@@ -4398,7 +4395,7 @@ int parx2s(
+@@ -4398,7 +4422,7 @@ int parx2s(
    return status;
  }
  
@@ -18095,7 +19924,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int pars2x(
    struct prjprm *prj,
-@@ -4420,7 +4417,7 @@ int pars2x(
+@@ -4420,7 +4444,7 @@ int pars2x(
    register double *xp, *yp;
  
  
@@ -18104,7 +19933,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != PAR) {
      if ((status = parset(prj))) return status;
-@@ -4436,7 +4433,7 @@ int pars2x(
+@@ -4436,7 +4460,7 @@ int pars2x(
    }
  
  
@@ -18113,7 +19942,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -4451,7 +4448,7 @@ int pars2x(
+@@ -4451,7 +4475,7 @@ int pars2x(
    }
  
  
@@ -18122,7 +19951,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -4523,7 +4520,7 @@ int molset(struct prjprm *prj)
+@@ -4523,7 +4547,7 @@ int molset(struct prjprm *prj)
    return prjoff(prj, 0.0, 0.0);
  }
  
@@ -18131,7 +19960,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int molx2s(
    struct prjprm *prj,
-@@ -4546,7 +4543,7 @@ int molx2s(
+@@ -4546,7 +4570,7 @@ int molx2s(
    register double *phip, *thetap;
  
  
@@ -18140,7 +19969,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != MOL) {
      if ((status = molset(prj))) return status;
-@@ -4564,7 +4561,7 @@ int molx2s(
+@@ -4564,7 +4588,7 @@ int molx2s(
    status = 0;
  
  
@@ -18149,7 +19978,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -4584,7 +4581,7 @@ int molx2s(
+@@ -4584,7 +4608,7 @@ int molx2s(
    }
  
  
@@ -18158,7 +19987,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -4600,7 +4597,7 @@ int molx2s(
+@@ -4600,7 +4624,7 @@ int molx2s(
          istat = 1;
          if (!status) status = PRJERR_BAD_PIX_SET("molx2s");
        } else {
@@ -18167,7 +19996,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          istat = -1;
        }
  
-@@ -4655,7 +4652,7 @@ int molx2s(
+@@ -4655,7 +4679,7 @@ int molx2s(
    }
  
  
@@ -18176,7 +20005,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-11, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("molx2s");
    }
-@@ -4663,7 +4660,7 @@ int molx2s(
+@@ -4663,7 +4687,7 @@ int molx2s(
    return status;
  }
  
@@ -18185,7 +20014,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int mols2x(
    struct prjprm *prj,
-@@ -4686,7 +4683,7 @@ int mols2x(
+@@ -4686,7 +4710,7 @@ int mols2x(
    register double *xp, *yp;
  
  
@@ -18194,7 +20023,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != MOL) {
      if ((status = molset(prj))) return status;
-@@ -4702,7 +4699,7 @@ int mols2x(
+@@ -4702,7 +4726,7 @@ int mols2x(
    }
  
  
@@ -18203,7 +20032,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -4717,7 +4714,7 @@ int mols2x(
+@@ -4717,7 +4741,7 @@ int mols2x(
    }
  
  
@@ -18212,7 +20041,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -4815,7 +4812,7 @@ int aitset(struct prjprm *prj)
+@@ -4815,7 +4839,7 @@ int aitset(struct prjprm *prj)
    return prjoff(prj, 0.0, 0.0);
  }
  
@@ -18221,7 +20050,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int aitx2s(
    struct prjprm *prj,
-@@ -4838,7 +4835,7 @@ int aitx2s(
+@@ -4838,7 +4862,7 @@ int aitx2s(
    register double *phip, *thetap;
  
  
@@ -18230,7 +20059,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != AIT) {
      if ((status = aitset(prj))) return status;
-@@ -4856,7 +4853,7 @@ int aitx2s(
+@@ -4856,7 +4880,7 @@ int aitx2s(
    status = 0;
  
  
@@ -18239,7 +20068,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -4876,7 +4873,7 @@ int aitx2s(
+@@ -4876,7 +4900,7 @@ int aitx2s(
    }
  
  
@@ -18248,7 +20077,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -4925,7 +4922,7 @@ int aitx2s(
+@@ -4925,7 +4949,7 @@ int aitx2s(
    }
  
  
@@ -18257,7 +20086,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("aitx2s");
    }
-@@ -4933,7 +4930,7 @@ int aitx2s(
+@@ -4933,7 +4957,7 @@ int aitx2s(
    return status;
  }
  
@@ -18266,7 +20095,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int aits2x(
    struct prjprm *prj,
-@@ -4955,7 +4952,7 @@ int aits2x(
+@@ -4955,7 +4979,7 @@ int aits2x(
    register double *xp, *yp;
  
  
@@ -18275,7 +20104,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != AIT) {
      if ((status = aitset(prj))) return status;
-@@ -4971,7 +4968,7 @@ int aits2x(
+@@ -4971,7 +4995,7 @@ int aits2x(
    }
  
  
@@ -18284,7 +20113,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -4990,7 +4987,7 @@ int aits2x(
+@@ -4990,7 +5014,7 @@ int aits2x(
    }
  
  
@@ -18293,7 +20122,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -5083,7 +5080,7 @@ int copset(struct prjprm *prj)
+@@ -5083,7 +5107,7 @@ int copset(struct prjprm *prj)
    return prjoff(prj, 0.0, prj->pv[1]);
  }
  
@@ -18302,7 +20131,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int copx2s(
    struct prjprm *prj,
-@@ -5104,7 +5101,7 @@ int copx2s(
+@@ -5104,7 +5128,7 @@ int copx2s(
    register const double *xp, *yp;
    register double *phip, *thetap;
  
@@ -18311,7 +20140,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != COP) {
      if ((status = copset(prj))) return status;
-@@ -5122,7 +5119,7 @@ int copx2s(
+@@ -5122,7 +5146,7 @@ int copx2s(
    status = 0;
  
  
@@ -18320,7 +20149,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -5137,7 +5134,7 @@ int copx2s(
+@@ -5137,7 +5161,7 @@ int copx2s(
    }
  
  
@@ -18329,7 +20158,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -5165,7 +5162,7 @@ int copx2s(
+@@ -5165,7 +5189,7 @@ int copx2s(
    }
  
  
@@ -18338,7 +20167,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("copx2s");
    }
-@@ -5173,7 +5170,7 @@ int copx2s(
+@@ -5173,7 +5197,7 @@ int copx2s(
    return status;
  }
  
@@ -18347,7 +20176,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int cops2x(
    struct prjprm *prj,
-@@ -5194,7 +5191,7 @@ int cops2x(
+@@ -5194,7 +5218,7 @@ int cops2x(
    register const double *phip, *thetap;
    register double *xp, *yp;
  
@@ -18356,7 +20185,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != COP) {
      if ((status = copset(prj))) return status;
-@@ -5212,7 +5209,7 @@ int cops2x(
+@@ -5212,7 +5236,7 @@ int cops2x(
    status = 0;
  
  
@@ -18365,7 +20194,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -5231,7 +5228,7 @@ int cops2x(
+@@ -5231,7 +5255,7 @@ int cops2x(
    }
  
  
@@ -18374,7 +20203,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -5243,16 +5240,16 @@ int cops2x(
+@@ -5243,16 +5267,16 @@ int cops2x(
  
      istat = 0;
      if (s == 0.0) {
@@ -18394,7 +20223,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        if (prj->bounds&1) {
          if ((*thetap < 0.0) != (prj->pv[1] < 0.0)) {
            istat = 1;
-@@ -5263,7 +5260,7 @@ int cops2x(
+@@ -5263,7 +5287,7 @@ int cops2x(
      } else {
        r = prj->w[2] - prj->w[3]*sind(t)/s;
  
@@ -18403,7 +20232,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        if (prj->bounds&1) {
          if (r*prj->w[0] < 0.0) {
            istat = 1;
-@@ -5363,7 +5360,7 @@ int coeset(struct prjprm *prj)
+@@ -5363,7 +5387,7 @@ int coeset(struct prjprm *prj)
    return prjoff(prj, 0.0, prj->pv[1]);
  }
  
@@ -18412,7 +20241,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int coex2s(
    struct prjprm *prj,
-@@ -5385,7 +5382,7 @@ int coex2s(
+@@ -5385,7 +5409,7 @@ int coex2s(
    register const double *xp, *yp;
    register double *phip, *thetap;
  
@@ -18421,7 +20250,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != COE) {
      if ((status = coeset(prj))) return status;
-@@ -5403,7 +5400,7 @@ int coex2s(
+@@ -5403,7 +5427,7 @@ int coex2s(
    status = 0;
  
  
@@ -18430,7 +20259,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -5418,7 +5415,7 @@ int coex2s(
+@@ -5418,7 +5442,7 @@ int coex2s(
    }
  
  
@@ -18439,7 +20268,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -5466,7 +5463,7 @@ int coex2s(
+@@ -5466,7 +5490,7 @@ int coex2s(
    }
  
  
@@ -18448,7 +20277,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("coex2s");
    }
-@@ -5474,7 +5471,7 @@ int coex2s(
+@@ -5474,7 +5498,7 @@ int coex2s(
    return status;
  }
  
@@ -18457,7 +20286,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int coes2x(
    struct prjprm *prj,
-@@ -5495,7 +5492,7 @@ int coes2x(
+@@ -5495,7 +5519,7 @@ int coes2x(
    register const double *phip, *thetap;
    register double *xp, *yp;
  
@@ -18466,7 +20295,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != COE) {
      if ((status = coeset(prj))) return status;
-@@ -5511,7 +5508,7 @@ int coes2x(
+@@ -5511,7 +5535,7 @@ int coes2x(
    }
  
  
@@ -18475,7 +20304,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -5530,7 +5527,7 @@ int coes2x(
+@@ -5530,7 +5554,7 @@ int coes2x(
    }
  
  
@@ -18484,7 +20313,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -5622,7 +5619,7 @@ int codset(struct prjprm *prj)
+@@ -5622,7 +5646,7 @@ int codset(struct prjprm *prj)
    return prjoff(prj, 0.0, prj->pv[1]);
  }
  
@@ -18493,7 +20322,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int codx2s(
    struct prjprm *prj,
-@@ -5643,7 +5640,7 @@ int codx2s(
+@@ -5643,7 +5667,7 @@ int codx2s(
    register const double *xp, *yp;
    register double *phip, *thetap;
  
@@ -18502,7 +20331,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != COD) {
      if ((status = codset(prj))) return status;
-@@ -5661,7 +5658,7 @@ int codx2s(
+@@ -5661,7 +5685,7 @@ int codx2s(
    status = 0;
  
  
@@ -18511,7 +20340,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -5676,7 +5673,7 @@ int codx2s(
+@@ -5676,7 +5700,7 @@ int codx2s(
    }
  
  
@@ -18520,7 +20349,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -5704,7 +5701,7 @@ int codx2s(
+@@ -5704,7 +5728,7 @@ int codx2s(
    }
  
  
@@ -18529,7 +20358,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("codx2s");
    }
-@@ -5712,7 +5709,7 @@ int codx2s(
+@@ -5712,7 +5736,7 @@ int codx2s(
    return status;
  }
  
@@ -18538,7 +20367,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int cods2x(
    struct prjprm *prj,
-@@ -5733,7 +5730,7 @@ int cods2x(
+@@ -5733,7 +5757,7 @@ int cods2x(
    register const double *phip, *thetap;
    register double *xp, *yp;
  
@@ -18547,7 +20376,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != COD) {
      if ((status = codset(prj))) return status;
-@@ -5749,7 +5746,7 @@ int cods2x(
+@@ -5749,7 +5773,7 @@ int cods2x(
    }
  
  
@@ -18556,7 +20385,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -5768,7 +5765,7 @@ int cods2x(
+@@ -5768,7 +5792,7 @@ int cods2x(
    }
  
  
@@ -18565,7 +20394,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -5873,7 +5870,7 @@ int cooset(struct prjprm *prj)
+@@ -5873,7 +5897,7 @@ int cooset(struct prjprm *prj)
    return prjoff(prj, 0.0, prj->pv[1]);
  }
  
@@ -18574,7 +20403,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int coox2s(
    struct prjprm *prj,
-@@ -5894,7 +5891,7 @@ int coox2s(
+@@ -5894,7 +5918,7 @@ int coox2s(
    register const double *xp, *yp;
    register double *phip, *thetap;
  
@@ -18583,7 +20412,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != COO) {
      if ((status = cooset(prj))) return status;
-@@ -5912,7 +5909,7 @@ int coox2s(
+@@ -5912,7 +5936,7 @@ int coox2s(
    status = 0;
  
  
@@ -18592,7 +20421,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -5927,7 +5924,7 @@ int coox2s(
+@@ -5927,7 +5951,7 @@ int coox2s(
    }
  
  
@@ -18601,7 +20430,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -5968,7 +5965,7 @@ int coox2s(
+@@ -5968,7 +5992,7 @@ int coox2s(
    }
  
  
@@ -18610,7 +20439,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("coox2s");
    }
-@@ -5976,7 +5973,7 @@ int coox2s(
+@@ -5976,7 +6000,7 @@ int coox2s(
    return status;
  }
  
@@ -18619,7 +20448,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int coos2x(
    struct prjprm *prj,
-@@ -5997,7 +5994,7 @@ int coos2x(
+@@ -5997,7 +6021,7 @@ int coos2x(
    register const double *phip, *thetap;
    register double *xp, *yp;
  
@@ -18628,7 +20457,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != COO) {
      if ((status = cooset(prj))) return status;
-@@ -6015,7 +6012,7 @@ int coos2x(
+@@ -6015,7 +6039,7 @@ int coos2x(
    status = 0;
  
  
@@ -18637,7 +20466,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -6034,7 +6031,7 @@ int coos2x(
+@@ -6034,7 +6058,7 @@ int coos2x(
    }
  
  
@@ -18646,7 +20475,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -6099,7 +6096,7 @@ int bonset(struct prjprm *prj)
+@@ -6099,7 +6123,7 @@ int bonset(struct prjprm *prj)
    }
  
    if (prj->pv[1] == 0.0) {
@@ -18655,7 +20484,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
      return sflset(prj);
    }
  
-@@ -6126,7 +6123,7 @@ int bonset(struct prjprm *prj)
+@@ -6126,7 +6150,7 @@ int bonset(struct prjprm *prj)
    return prjoff(prj, 0.0, 0.0);
  }
  
@@ -18664,7 +20493,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int bonx2s(
    struct prjprm *prj,
-@@ -6148,10 +6145,10 @@ int bonx2s(
+@@ -6148,10 +6172,10 @@ int bonx2s(
    register double *phip, *thetap;
  
  
@@ -18677,7 +20506,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
      return sflx2s(prj, nx, ny, sxy, spt, x, y, phi, theta, stat);
    }
  
-@@ -6171,7 +6168,7 @@ int bonx2s(
+@@ -6171,7 +6195,7 @@ int bonx2s(
    status = 0;
  
  
@@ -18686,7 +20515,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -6186,7 +6183,7 @@ int bonx2s(
+@@ -6186,7 +6210,7 @@ int bonx2s(
    }
  
  
@@ -18695,7 +20524,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -6222,7 +6219,7 @@ int bonx2s(
+@@ -6222,7 +6246,7 @@ int bonx2s(
    }
  
  
@@ -18704,7 +20533,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-11, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("bonx2s");
    }
-@@ -6230,7 +6227,7 @@ int bonx2s(
+@@ -6230,7 +6254,7 @@ int bonx2s(
    return status;
  }
  
@@ -18713,7 +20542,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int bons2x(
    struct prjprm *prj,
-@@ -6251,10 +6248,10 @@ int bons2x(
+@@ -6251,10 +6275,10 @@ int bons2x(
    register const double *phip, *thetap;
    register double *xp, *yp;
  
@@ -18726,7 +20555,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
      return sfls2x(prj, nphi, ntheta, spt, sxy, phi, theta, x, y, stat);
    }
  
-@@ -6274,7 +6271,7 @@ int bons2x(
+@@ -6274,7 +6298,7 @@ int bons2x(
    y0 = prj->y0 - prj->w[2];
  
  
@@ -18735,7 +20564,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -6289,7 +6286,7 @@ int bons2x(
+@@ -6289,7 +6313,7 @@ int bons2x(
    }
  
  
@@ -18744,7 +20573,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -6366,7 +6363,7 @@ int pcoset(struct prjprm *prj)
+@@ -6366,7 +6390,7 @@ int pcoset(struct prjprm *prj)
    return prjoff(prj, 0.0, 0.0);
  }
  
@@ -18753,7 +20582,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int pcox2s(
    struct prjprm *prj,
-@@ -6390,7 +6387,7 @@ int pcox2s(
+@@ -6390,7 +6414,7 @@ int pcox2s(
    register double *phip, *thetap;
  
  
@@ -18762,7 +20591,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != PCO) {
      if ((status = pcoset(prj))) return status;
-@@ -6408,7 +6405,7 @@ int pcox2s(
+@@ -6408,7 +6432,7 @@ int pcox2s(
    status = 0;
  
  
@@ -18771,7 +20600,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -6423,7 +6420,7 @@ int pcox2s(
+@@ -6423,7 +6447,7 @@ int pcox2s(
    }
  
  
@@ -18780,7 +20609,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -6445,23 +6442,23 @@ int pcox2s(
+@@ -6445,23 +6469,23 @@ int pcox2s(
  
        } else {
          if (w < 1.0e-4) {
@@ -18808,7 +20637,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
              lambda = fpos/(fpos-fneg);
              if (lambda < 0.1) {
                lambda = 0.1;
-@@ -6470,16 +6467,16 @@ int pcox2s(
+@@ -6470,16 +6494,16 @@ int pcox2s(
              }
              the = thepos - lambda*(thepos-theneg);
  
@@ -18828,7 +20657,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
              if (f > 0.0) {
                thepos = the;
                fpos = f;
-@@ -6506,7 +6503,7 @@ int pcox2s(
+@@ -6506,7 +6530,7 @@ int pcox2s(
    }
  
  
@@ -18837,7 +20666,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-12, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("pcox2s");
    }
-@@ -6514,7 +6511,7 @@ int pcox2s(
+@@ -6514,7 +6538,7 @@ int pcox2s(
    return status;
  }
  
@@ -18846,7 +20675,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int pcos2x(
    struct prjprm *prj,
-@@ -6535,7 +6532,7 @@ int pcos2x(
+@@ -6535,7 +6559,7 @@ int pcos2x(
    register const double *phip, *thetap;
    register double *xp, *yp;
  
@@ -18855,7 +20684,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != PCO) {
      if ((status = pcoset(prj))) return status;
-@@ -6551,7 +6548,7 @@ int pcos2x(
+@@ -6551,7 +6575,7 @@ int pcos2x(
    }
  
  
@@ -18864,7 +20693,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -6564,7 +6561,7 @@ int pcos2x(
+@@ -6564,7 +6588,7 @@ int pcos2x(
    }
  
  
@@ -18873,7 +20702,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -6578,7 +6575,7 @@ int pcos2x(
+@@ -6578,7 +6602,7 @@ int pcos2x(
        }
  
      } else if (fabs(*thetap) < 1.0e-4) {
@@ -18882,7 +20711,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        for (iphi = 0; iphi < mphi; iphi++, xp += sxy, yp += sxy) {
          *xp = prj->w[0]*(*xp)*cosd(*thetap) - prj->x0;
          *yp = (prj->w[0] + prj->w[3]*(*xp)*(*xp))*(*thetap) - prj->y0;
-@@ -6653,7 +6650,7 @@ int tscset(struct prjprm *prj)
+@@ -6653,7 +6677,7 @@ int tscset(struct prjprm *prj)
    return prjoff(prj, 0.0, 0.0);
  }
  
@@ -18891,7 +20720,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int tscx2s(
    struct prjprm *prj,
-@@ -6675,7 +6672,7 @@ int tscx2s(
+@@ -6675,7 +6699,7 @@ int tscx2s(
    register double *phip, *thetap;
  
  
@@ -18900,7 +20729,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != TSC) {
      if ((status = tscset(prj))) return status;
-@@ -6693,7 +6690,7 @@ int tscx2s(
+@@ -6693,7 +6717,7 @@ int tscx2s(
    status = 0;
  
  
@@ -18909,7 +20738,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -6708,7 +6705,7 @@ int tscx2s(
+@@ -6708,7 +6732,7 @@ int tscx2s(
    }
  
  
@@ -18918,7 +20747,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -6719,7 +6716,7 @@ int tscx2s(
+@@ -6719,7 +6743,7 @@ int tscx2s(
      for (ix = 0; ix < mx; ix++, phip += spt, thetap += spt) {
        xf = *phip;
  
@@ -18927,7 +20756,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        if (fabs(xf) <= 1.0) {
          if (fabs(yf) > 3.0) {
            *phip = 0.0;
-@@ -6738,42 +6735,42 @@ int tscx2s(
+@@ -6738,42 +6762,42 @@ int tscx2s(
          }
        }
  
@@ -18978,7 +20807,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          l  =  1.0/sqrt(1.0 + xf*xf + yf*yf);
          m  =  l*xf;
          n  =  l*yf;
-@@ -6791,7 +6788,7 @@ int tscx2s(
+@@ -6791,7 +6815,7 @@ int tscx2s(
    }
  
  
@@ -18987,7 +20816,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("tscx2s");
    }
-@@ -6799,7 +6796,7 @@ int tscx2s(
+@@ -6799,7 +6823,7 @@ int tscx2s(
    return status;
  }
  
@@ -18996,7 +20825,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int tscs2x(
    struct prjprm *prj,
-@@ -6821,7 +6818,7 @@ int tscs2x(
+@@ -6821,7 +6845,7 @@ int tscs2x(
    register const double *phip, *thetap;
    register double *xp, *yp;
  
@@ -19005,7 +20834,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != TSC) {
      if ((status = tscset(prj))) return status;
-@@ -6839,7 +6836,7 @@ int tscs2x(
+@@ -6839,7 +6863,7 @@ int tscs2x(
    status = 0;
  
  
@@ -19014,7 +20843,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -6857,7 +6854,7 @@ int tscs2x(
+@@ -6857,7 +6881,7 @@ int tscs2x(
    }
  
  
@@ -19023,7 +20852,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -6925,7 +6922,7 @@ int tscs2x(
+@@ -6925,7 +6949,7 @@ int tscs2x(
          y0 = -2.0;
          break;
        default:
@@ -19032,7 +20861,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          xf =  m/zeta;
          yf = -l/zeta;
          x0 =  0.0;
-@@ -7009,7 +7006,7 @@ int cscset(struct prjprm *prj)
+@@ -7009,7 +7033,7 @@ int cscset(struct prjprm *prj)
    return prjoff(prj, 0.0, 0.0);
  }
  
@@ -19041,7 +20870,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int cscx2s(
    struct prjprm *prj,
-@@ -7060,7 +7057,7 @@ int cscx2s(
+@@ -7060,7 +7084,7 @@ int cscx2s(
    const float p15 =  0.52032238f;
    const float p06 =  0.14381585f;
  
@@ -19050,7 +20879,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != CSC) {
      if ((status = cscset(prj))) return status;
-@@ -7078,7 +7075,7 @@ int cscx2s(
+@@ -7078,7 +7102,7 @@ int cscx2s(
    status = 0;
  
  
@@ -19059,7 +20888,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -7093,7 +7090,7 @@ int cscx2s(
+@@ -7093,7 +7117,7 @@ int cscx2s(
    }
  
  
@@ -19068,7 +20897,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -7104,7 +7101,7 @@ int cscx2s(
+@@ -7104,7 +7128,7 @@ int cscx2s(
      for (ix = 0; ix < mx; ix++, phip += spt, thetap += spt) {
        xf = (float)(*phip);
  
@@ -19077,7 +20906,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        if (fabs((double)xf) <= 1.0) {
          if (fabs((double)yf) > 3.0) {
            *phip = 0.0;
-@@ -7123,10 +7120,10 @@ int cscx2s(
+@@ -7123,10 +7147,10 @@ int cscx2s(
          }
        }
  
@@ -19090,7 +20919,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        if (xf > 5.0f) {
          face = 4;
          xf = xf - 6.0f;
-@@ -7201,7 +7198,7 @@ int cscx2s(
+@@ -7201,7 +7225,7 @@ int cscx2s(
          m = -chi*n;
          break;
        default:
@@ -19099,7 +20928,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          n =  t;
          l = -psi*n;
          m =  chi*n;
-@@ -7220,7 +7217,7 @@ int cscx2s(
+@@ -7220,7 +7244,7 @@ int cscx2s(
    }
  
  
@@ -19108,7 +20937,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("cscx2s");
    }
-@@ -7228,7 +7225,7 @@ int cscx2s(
+@@ -7228,7 +7252,7 @@ int cscx2s(
    return status;
  }
  
@@ -19117,7 +20946,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int cscs2x(
    struct prjprm *prj,
-@@ -7266,7 +7263,7 @@ int cscs2x(
+@@ -7266,7 +7290,7 @@ int cscs2x(
    const float c02 =  0.106959469314f;
  
  
@@ -19126,7 +20955,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != CSC) {
      if ((status = cscset(prj))) return status;
-@@ -7284,7 +7281,7 @@ int cscs2x(
+@@ -7284,7 +7308,7 @@ int cscs2x(
    status = 0;
  
  
@@ -19135,7 +20964,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -7302,7 +7299,7 @@ int cscs2x(
+@@ -7302,7 +7326,7 @@ int cscs2x(
    }
  
  
@@ -19144,7 +20973,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -7370,7 +7367,7 @@ int cscs2x(
+@@ -7370,7 +7394,7 @@ int cscs2x(
          y0  = -2.0;
          break;
        default:
@@ -19153,7 +20982,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          xi  =  m;
          eta = -l;
          x0  =  0.0;
-@@ -7386,7 +7383,7 @@ int cscs2x(
+@@ -7386,7 +7410,7 @@ int cscs2x(
        chi2co = 1.0f - chi2;
        psi2co = 1.0f - psi2;
  
@@ -19162,7 +20991,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        chipsi = (float)fabs((double)(chi*psi));
        chi4   = (chi2 > 1.0e-16f) ? chi2*chi2 : 0.0f;
        psi4   = (psi2 > 1.0e-16f) ? psi2*psi2 : 0.0f;
-@@ -7475,7 +7472,7 @@ int qscset(struct prjprm *prj)
+@@ -7475,7 +7499,7 @@ int qscset(struct prjprm *prj)
    return prjoff(prj, 0.0, 0.0);
  }
  
@@ -19171,7 +21000,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int qscx2s(
    struct prjprm *prj,
-@@ -7498,7 +7495,7 @@ int qscx2s(
+@@ -7498,7 +7522,7 @@ int qscx2s(
    register double *phip, *thetap;
  
  
@@ -19180,7 +21009,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != QSC) {
      if ((status = qscset(prj))) return status;
-@@ -7516,7 +7513,7 @@ int qscx2s(
+@@ -7516,7 +7540,7 @@ int qscx2s(
    status = 0;
  
  
@@ -19189,7 +21018,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -7531,7 +7528,7 @@ int qscx2s(
+@@ -7531,7 +7555,7 @@ int qscx2s(
    }
  
  
@@ -19198,7 +21027,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -7542,7 +7539,7 @@ int qscx2s(
+@@ -7542,7 +7566,7 @@ int qscx2s(
      for (ix = 0; ix < mx; ix++, phip += spt, thetap += spt) {
        xf = *phip;
  
@@ -19207,7 +21036,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        if (fabs(xf) <= 1.0) {
          if (fabs(yf) > 3.0) {
            *phip = 0.0;
-@@ -7561,10 +7558,10 @@ int qscx2s(
+@@ -7561,10 +7585,10 @@ int qscx2s(
          }
        }
  
@@ -19220,7 +21049,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        if (xf > 5.0) {
          face = 4;
          xf -= 6.0;
-@@ -7692,7 +7689,7 @@ int qscx2s(
+@@ -7692,7 +7716,7 @@ int qscx2s(
          }
          break;
        default:
@@ -19229,7 +21058,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          n = zeta;
          if (direct) {
            m = w;
-@@ -7718,7 +7715,7 @@ int qscx2s(
+@@ -7718,7 +7742,7 @@ int qscx2s(
    }
  
  
@@ -19238,7 +21067,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-13, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("qscx2s");
    }
-@@ -7726,7 +7723,7 @@ int qscx2s(
+@@ -7726,7 +7750,7 @@ int qscx2s(
    return status;
  }
  
@@ -19247,7 +21076,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int qscs2x(
    struct prjprm *prj,
-@@ -7750,7 +7747,7 @@ int qscs2x(
+@@ -7750,7 +7774,7 @@ int qscs2x(
    register double *xp, *yp;
  
  
@@ -19256,7 +21085,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != QSC) {
      if ((status = qscset(prj))) return status;
-@@ -7768,7 +7765,7 @@ int qscs2x(
+@@ -7768,7 +7792,7 @@ int qscs2x(
    status = 0;
  
  
@@ -19265,7 +21094,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -7786,7 +7783,7 @@ int qscs2x(
+@@ -7786,7 +7810,7 @@ int qscs2x(
    }
  
  
@@ -19274,7 +21103,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -7836,7 +7833,7 @@ int qscs2x(
+@@ -7836,7 +7860,7 @@ int qscs2x(
          xi  = m;
          eta = n;
          if (zeco < 1.0e-8) {
@@ -19283,7 +21112,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
            t = (*thetap)*D2R;
            p = atan2(*yp, *xp);
            zeco = (p*p + t*t)/2.0;
-@@ -7848,7 +7845,7 @@ int qscs2x(
+@@ -7848,7 +7872,7 @@ int qscs2x(
          xi  = -l;
          eta =  n;
          if (zeco < 1.0e-8) {
@@ -19292,7 +21121,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
            t = (*thetap)*D2R;
            p = atan2(*yp, *xp) - PI/2.0;
            zeco = (p*p + t*t)/2.0;
-@@ -7860,7 +7857,7 @@ int qscs2x(
+@@ -7860,7 +7884,7 @@ int qscs2x(
          xi  = -m;
          eta =  n;
          if (zeco < 1.0e-8) {
@@ -19301,7 +21130,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
            t = (*thetap)*D2R;
            p = atan2(*yp, *xp);
            p -= copysign(PI, p);
-@@ -7873,7 +7870,7 @@ int qscs2x(
+@@ -7873,7 +7897,7 @@ int qscs2x(
          xi  = l;
          eta = n;
          if (zeco < 1.0e-8) {
@@ -19310,7 +21139,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
            t = (*thetap)*D2R;
            p = atan2(*yp, *xp) + PI/2.0;
            zeco = (p*p + t*t)/2.0;
-@@ -7885,7 +7882,7 @@ int qscs2x(
+@@ -7885,7 +7909,7 @@ int qscs2x(
          xi  =  m;
          eta =  l;
          if (zeco < 1.0e-8) {
@@ -19319,7 +21148,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
            t = (*thetap + 90.0)*D2R;
            zeco = t*t/2.0;
          }
-@@ -7893,11 +7890,11 @@ int qscs2x(
+@@ -7893,11 +7917,11 @@ int qscs2x(
          y0 = -2;
           break;
        default:
@@ -19333,7 +21162,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
            t = (90.0 - *thetap)*D2R;
            zeco = t*t/2.0;
          }
-@@ -8041,7 +8038,7 @@ int hpxset(struct prjprm *prj)
+@@ -8041,7 +8065,7 @@ int hpxset(struct prjprm *prj)
    return prjoff(prj, 0.0, 0.0);
  }
  
@@ -19342,7 +21171,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int hpxx2s(
    struct prjprm *prj,
-@@ -8063,7 +8060,7 @@ int hpxx2s(
+@@ -8063,7 +8087,7 @@ int hpxx2s(
    register double *phip, *thetap;
  
  
@@ -19351,7 +21180,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != HPX) {
      if ((status = hpxset(prj))) return status;
-@@ -8084,20 +8081,20 @@ int hpxx2s(
+@@ -8084,20 +8108,20 @@ int hpxx2s(
    status = 0;
  
  
@@ -19375,7 +21204,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        *phip   = s;
        *thetap = t;
        phip   += rowlen;
-@@ -8106,7 +8103,7 @@ int hpxx2s(
+@@ -8106,7 +8130,7 @@ int hpxx2s(
    }
  
  
@@ -19384,7 +21213,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -8117,7 +8114,7 @@ int hpxx2s(
+@@ -8117,7 +8141,7 @@ int hpxx2s(
  
      istat = 0;
      if (absy <= prj->w[5]) {
@@ -19393,7 +21222,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        t = asind(yr/prj->w[3]);
        for (ix = 0; ix < mx; ix++, phip += spt, thetap += spt) {
          *thetap = t;
-@@ -8125,7 +8122,7 @@ int hpxx2s(
+@@ -8125,7 +8149,7 @@ int hpxx2s(
        }
  
      } else if (absy <= ylim) {
@@ -19402,7 +21231,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        offset = (prj->n || *yp > 0.0) ? 0 : 1;
  
        sigma = prj->w[4] - absy / prj->w[6];
-@@ -8150,7 +8147,7 @@ int hpxx2s(
+@@ -8150,7 +8174,7 @@ int hpxx2s(
  
        for (ix = 0; ix < mx; ix++, phip += spt, thetap += spt) {
          if (offset) {
@@ -19411,7 +21240,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
            h = (int)floor(*phip / prj->w[6]) + prj->m;
            if (h%2) {
              *thetap -= prj->w[6];
-@@ -8159,10 +8156,10 @@ int hpxx2s(
+@@ -8159,10 +8183,10 @@ int hpxx2s(
            }
          }
  
@@ -19424,7 +21253,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          if (prj->bounds&2) {
            if (slim <= fabs(r)) {
              istat = 1;
-@@ -8178,7 +8175,7 @@ int hpxx2s(
+@@ -8178,7 +8202,7 @@ int hpxx2s(
        }
  
      } else {
@@ -19433,7 +21262,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        for (ix = 0; ix < mx; ix++, phip += spt, thetap += spt) {
          *phip   = 0.0;
          *thetap = 0.0;
-@@ -8189,7 +8186,7 @@ int hpxx2s(
+@@ -8189,7 +8213,7 @@ int hpxx2s(
    }
  
  
@@ -19442,7 +21271,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-12, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("hpxx2s");
    }
-@@ -8197,7 +8194,7 @@ int hpxx2s(
+@@ -8197,7 +8221,7 @@ int hpxx2s(
    return status;
  }
  
@@ -19451,7 +21280,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int hpxs2x(
    struct prjprm *prj,
-@@ -8219,7 +8216,7 @@ int hpxs2x(
+@@ -8219,7 +8243,7 @@ int hpxs2x(
    register double *xp, *yp;
  
  
@@ -19460,7 +21289,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != HPX) {
      if ((status = hpxset(prj))) return status;
-@@ -8235,21 +8232,21 @@ int hpxs2x(
+@@ -8235,21 +8259,21 @@ int hpxs2x(
    }
  
  
@@ -19485,7 +21314,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        *xp = xi;
        *yp = t;
        xp += rowlen;
-@@ -8258,7 +8255,7 @@ int hpxs2x(
+@@ -8258,7 +8282,7 @@ int hpxs2x(
    }
  
  
@@ -19494,7 +21323,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -8268,7 +8265,7 @@ int hpxs2x(
+@@ -8268,7 +8292,7 @@ int hpxs2x(
      abssin = fabs(sinthe);
  
      if (abssin <= prj->w[2]) {
@@ -19503,7 +21332,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        eta = prj->w[8] * sinthe - prj->y0;
        for (iphi = 0; iphi < mphi; iphi++, xp += sxy, yp += sxy) {
          *yp = eta;
-@@ -8276,7 +8273,7 @@ int hpxs2x(
+@@ -8276,7 +8300,7 @@ int hpxs2x(
        }
  
      } else {
@@ -19512,7 +21341,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        offset = (prj->n || *thetap > 0.0) ? 0 : 1;
  
        sigma = sqrt(prj->pv[2]*(1.0 - abssin));
-@@ -8288,7 +8285,7 @@ int hpxs2x(
+@@ -8288,7 +8312,7 @@ int hpxs2x(
  
        for (iphi = 0; iphi < mphi; iphi++, xp += sxy, yp += sxy) {
          if (offset) {
@@ -19521,7 +21350,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
            h = (int)floor((*xp + prj->x0) / prj->w[9]) + prj->m;
            if (h%2) {
              *yp -= prj->w[9];
-@@ -8297,12 +8294,12 @@ int hpxs2x(
+@@ -8297,12 +8321,12 @@ int hpxs2x(
            }
          }
  
@@ -19536,7 +21365,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          if (180.0 < *xp) *xp = 360.0 - *xp;
        }
      }
-@@ -8375,7 +8372,7 @@ int xphset(struct prjprm *prj)
+@@ -8375,7 +8399,7 @@ int xphset(struct prjprm *prj)
    return prjoff(prj, 0.0, 90.0);
  }
  
@@ -19545,7 +21374,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int xphx2s(
    struct prjprm *prj,
-@@ -8398,7 +8395,7 @@ int xphx2s(
+@@ -8398,7 +8422,7 @@ int xphx2s(
    register double *phip, *thetap;
  
  
@@ -19554,7 +21383,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != XPH) {
      if ((status = xphset(prj))) return status;
-@@ -8416,7 +8413,7 @@ int xphx2s(
+@@ -8416,7 +8440,7 @@ int xphx2s(
    status = 0;
  
  
@@ -19563,7 +21392,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    xp = x;
    rowoff = 0;
    rowlen = nx*spt;
-@@ -8431,7 +8428,7 @@ int xphx2s(
+@@ -8431,7 +8455,7 @@ int xphx2s(
    }
  
  
@@ -19572,7 +21401,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    yp = y;
    phip   = phi;
    thetap = theta;
-@@ -8466,12 +8463,12 @@ int xphx2s(
+@@ -8466,12 +8490,12 @@ int xphx2s(
  
        if (abseta <= 90.0) {
          if (abseta <= 45.0) {
@@ -19587,7 +21416,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
            if (prj->bounds&2) {
              if (45.0+tol < fabs(xi1)) {
                istat = 1;
-@@ -8482,10 +8479,10 @@ int xphx2s(
+@@ -8482,10 +8506,10 @@ int xphx2s(
            *(statp++) = istat;
  
          } else {
@@ -19600,7 +21429,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
            if (xr == 0.0) {
              if (yr <= 0.0) {
                *phip = 0.0;
-@@ -8509,7 +8506,7 @@ int xphx2s(
+@@ -8509,7 +8533,7 @@ int xphx2s(
            }
            if (eta < 0.0) *thetap = -(*thetap);
  
@@ -19609,7 +21438,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
            istat = 0;
            if (prj->bounds&2) {
              if (eta < -45.0 && eta+90.0+tol < fabs(xi1)) {
-@@ -8522,7 +8519,7 @@ int xphx2s(
+@@ -8522,7 +8546,7 @@ int xphx2s(
          }
  
        } else {
@@ -19618,7 +21447,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          *phip   = 0.0;
          *thetap = 0.0;
          *(statp++) = 1;
-@@ -8532,7 +8529,7 @@ int xphx2s(
+@@ -8532,7 +8556,7 @@ int xphx2s(
    }
  
  
@@ -19627,7 +21456,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj->bounds&4 && prjbchk(1.0e-12, nx, my, spt, phi, theta, stat)) {
      if (!status) status = PRJERR_BAD_PIX_SET("xphx2s");
    }
-@@ -8540,7 +8537,7 @@ int xphx2s(
+@@ -8540,7 +8564,7 @@ int xphx2s(
    return status;
  }
  
@@ -19636,7 +21465,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
  
  int xphs2x(
    struct prjprm *prj,
-@@ -8562,7 +8559,7 @@ int xphs2x(
+@@ -8562,7 +8586,7 @@ int xphs2x(
    register double *xp, *yp;
  
  
@@ -19645,7 +21474,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    if (prj == 0x0) return PRJERR_NULL_POINTER;
    if (prj->flag != XPH) {
      if ((status = xphset(prj))) return status;
-@@ -8578,7 +8575,7 @@ int xphs2x(
+@@ -8578,7 +8602,7 @@ int xphs2x(
    }
  
  
@@ -19654,7 +21483,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    phip = phi;
    rowoff = 0;
    rowlen = nphi*sxy;
-@@ -8593,14 +8590,14 @@ int xphs2x(
+@@ -8593,14 +8617,14 @@ int xphs2x(
        }
      }
  
@@ -19671,7 +21500,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        *xp = psi;
        *yp = chi - 180.0;
        xp += rowlen;
-@@ -8609,7 +8606,7 @@ int xphs2x(
+@@ -8609,7 +8633,7 @@ int xphs2x(
    }
  
  
@@ -19680,7 +21509,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
    thetap = theta;
    xp = x;
    yp = y;
-@@ -8620,12 +8617,12 @@ int xphs2x(
+@@ -8620,12 +8644,12 @@ int xphs2x(
  
      for (iphi = 0; iphi < mphi; iphi++, xp += sxy, yp += sxy) {
        if (abssin <= prj->w[2]) {
@@ -19695,7 +21524,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
          if (*thetap < prj->w[5]) {
            sigma = sqrt(3.0*(1.0 - abssin));
          } else {
-@@ -8640,7 +8637,7 @@ int xphs2x(
+@@ -8640,7 +8664,7 @@ int xphs2x(
        xi  -= 45.0;
        eta -= 90.0;
  
@@ -19704,16 +21533,16 @@ Index: astropy-4.2/cextern/wcslib/C/prj.c
        if (*yp < -90.0) {
          *xp = prj->w[0]*(-xi + eta) - prj->x0;
          *yp = prj->w[0]*(-xi - eta) - prj->y0;
-Index: astropy-4.2/cextern/wcslib/C/prj.h
+Index: astropy-4.2.1/cextern/wcslib/C/prj.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/prj.h
-+++ astropy-4.2/cextern/wcslib/C/prj.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/prj.h
++++ astropy-4.2.1/cextern/wcslib/C/prj.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -19727,15 +21556,69 @@ Index: astropy-4.2/cextern/wcslib/C/prj.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: prj.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: prj.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: prj.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
-@@ -630,19 +627,19 @@ extern "C" {
+@@ -54,7 +51,8 @@
+ *
+ * Routine prjini() is provided to initialize the prjprm struct with default
+ * values, prjfree() reclaims any memory that may have been allocated to store
+-* an error message, and prjprt() prints its contents.
++* an error message, prjsize() computes its total size including allocated
++* memory, and prjprt() prints its contents.
+ *
+ * prjperr() prints the error message(s) (if any) stored in a prjprm struct.
+ * prjbchk() performs bounds checking on native spherical coordinates.
+@@ -76,7 +74,8 @@
+ * In summary, the routines are:
+ *   - prjini()                Initialization routine for the prjprm struct.
+ *   - prjfree()               Reclaim memory allocated for error messages.
+-*   - prjprt()                Print the prjprm struct.
++*   - prjsize()               Compute total size of a prjprm struct.
++*   - prjprt()                Print a prjprm struct.
+ *   - prjperr()               Print error message (if any).
+ *   - prjbchk()               Bounds checking on native coordinates.
+ *
+@@ -184,6 +183,33 @@
+ *                         1: Null prjprm pointer passed.
+ *
+ *
++* prjsize() - Compute the size of a prjprm struct
++* -----------------------------------------------
++* prjsize() computes the full size of a prjprm struct, including allocated
++* memory.
++*
++* Given:
++*   prj       const struct prjprm*
++*                       Projection parameters.
++*
++*                       If NULL, the base size of the struct and the allocated
++*                       size are both set to zero.
++*
++* Returned:
++*   sizes     int[2]    The first element is the base size of the struct as
++*                       returned by sizeof(struct prjprm).  The second element
++*                       is the total allocated size, in bytes.  This figure
++*                       includes memory allocated for the constituent struct,
++*                       prjprm::err.
++*
++*                       It is not an error for the struct not to have been set
++*                       up via prjset().
++*
++* Function return value:
++*             int       Status return value:
++*                         0: Success.
++*
++*
+ * prjprt() - Print routine for the prjprm struct
+ * ----------------------------------------------
+ * prjprt() prints the contents of a prjprm struct using wcsprintf().  Mainly
+@@ -630,19 +656,19 @@ extern "C" {
  #endif
  
  
@@ -19763,7 +21646,7 @@ Index: astropy-4.2/cextern/wcslib/C/prj.h
  };
  
  extern const int CONIC, CONVENTIONAL, CYLINDRICAL, POLYCONIC,
-@@ -660,59 +657,59 @@ extern const char prj_codes[28][4];
+@@ -660,66 +686,72 @@ extern const char prj_codes[28][4];
  #undef PRJS2X_ARGS
  #endif
  
@@ -19855,11 +21738,24 @@ Index: astropy-4.2/cextern/wcslib/C/prj.h
  
  
 -/* Use the preprocessor to help declare function prototypes (see above). */
-+// Use the preprocessor to help declare function prototypes (see above).
  int prjini(struct prjprm *prj);
++
  int prjfree(struct prjprm *prj);
++
++int prjsize(const struct prjprm *prj, int sizes[2]);
++
  int prjprt(const struct prjprm *prj);
-@@ -837,7 +834,7 @@ int xphx2s(PRJX2S_ARGS);
++
+ int prjperr(const struct prjprm *prj, const char *prefix);
++
+ int prjbchk(double tol, int nphi, int ntheta, int spt, double phi[],
+             double theta[], int stat[]);
+ 
++// Use the preprocessor to help declare function prototypes (see above).
+ int prjset(struct prjprm *prj);
+ int prjx2s(PRJX2S_ARGS);
+ int prjs2x(PRJS2X_ARGS);
+@@ -837,7 +869,7 @@ int xphx2s(PRJX2S_ARGS);
  int xphs2x(PRJS2X_ARGS);
  
  
@@ -19868,22 +21764,22 @@ Index: astropy-4.2/cextern/wcslib/C/prj.h
  #define prjini_errmsg prj_errmsg
  #define prjprt_errmsg prj_errmsg
  #define prjset_errmsg prj_errmsg
-@@ -848,4 +845,4 @@ int xphs2x(PRJS2X_ARGS);
+@@ -848,4 +880,4 @@ int xphs2x(PRJS2X_ARGS);
  }
  #endif
  
 -#endif /* WCSLIB_PROJ */
 +#endif // WCSLIB_PROJ
-Index: astropy-4.2/cextern/wcslib/C/spc.c
+Index: astropy-4.2.1/cextern/wcslib/C/spc.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/spc.c
-+++ astropy-4.2/cextern/wcslib/C/spc.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/spc.c
++++ astropy-4.2.1/cextern/wcslib/C/spc.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -19897,7 +21793,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: spc.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: spc.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: spc.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <math.h>
@@ -19995,16 +21891,41 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
  
  int spcfree(struct spcprm *spc)
  
-@@ -138,7 +135,7 @@ int spcfree(struct spcprm *spc)
+@@ -138,7 +135,32 @@ int spcfree(struct spcprm *spc)
    return 0;
  }
  
 -/*--------------------------------------------------------------------------*/
++//----------------------------------------------------------------------------
++
++int spcsize(const struct spcprm *spc, int sizes[2])
++
++{
++  if (spc == 0x0) {
++    sizes[0] = sizes[1] = 0;
++    return SPCERR_SUCCESS;
++  }
++
++  // Base size, in bytes.
++  sizes[0] = sizeof(struct spcprm);
++
++  // Total size of allocated memory, in bytes.
++  sizes[1] = 0;
++
++  int exsizes[2];
++
++  // spcprm::err.
++  wcserr_size(spc->err, exsizes);
++  sizes[1] += exsizes[0] + exsizes[1];
++
++  return SPCERR_SUCCESS;
++}
++
 +//----------------------------------------------------------------------------
  
  int spcprt(const struct spcprm *spc)
  
-@@ -215,7 +212,7 @@ int spcprt(const struct spcprm *spc)
+@@ -215,7 +237,7 @@ int spcprt(const struct spcprm *spc)
    return 0;
  }
  
@@ -20013,7 +21934,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
  
  int spcperr(const struct spcprm *spc, const char *prefix)
  
-@@ -229,7 +226,7 @@ int spcperr(const struct spcprm *spc, co
+@@ -229,7 +251,7 @@ int spcperr(const struct spcprm *spc, co
    return 0;
  }
  
@@ -20022,7 +21943,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
  
  int spcset(struct spcprm *spc)
  
-@@ -257,7 +254,7 @@ int spcset(struct spcprm *spc)
+@@ -257,7 +279,7 @@ int spcset(struct spcprm *spc)
    spc->w[0] = 0.0;
  
  
@@ -20031,7 +21952,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    memset(ctype, 0, 9);
    memcpy(ctype, spc->type, 4);
    if (*(spc->code) != ' ') {
-@@ -270,12 +267,12 @@ int spcset(struct spcprm *spc)
+@@ -270,12 +292,12 @@ int spcset(struct spcprm *spc)
      return status;
    }
  
@@ -20048,7 +21969,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
        restwav = 1.0;
      }
  
-@@ -302,34 +299,34 @@ int spcset(struct spcprm *spc)
+@@ -302,34 +324,34 @@ int spcset(struct spcprm *spc)
    spc->w[2] = dXdS;
  
  
@@ -20089,7 +22010,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
        spc->flag = VRAD;
        spc->spxP2S = freqvrad;
        spc->spxS2P = vradfreq;
-@@ -337,19 +334,19 @@ int spcset(struct spcprm *spc)
+@@ -337,19 +359,19 @@ int spcset(struct spcprm *spc)
  
    } else if (ptype == 'W') {
      if (strcmp(spc->type, "WAVE") == 0) {
@@ -20112,7 +22033,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
        spc->flag = ZOPT;
        spc->spxP2S = wavezopt;
        spc->spxS2P = zoptwave;
-@@ -357,7 +354,7 @@ int spcset(struct spcprm *spc)
+@@ -357,7 +379,7 @@ int spcset(struct spcprm *spc)
  
    } else if (ptype == 'A') {
      if (strcmp(spc->type, "AWAV") == 0) {
@@ -20121,7 +22042,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
        spc->flag = AWAV;
        spc->spxP2S = 0x0;
        spc->spxS2P = 0x0;
-@@ -365,13 +362,13 @@ int spcset(struct spcprm *spc)
+@@ -365,13 +387,13 @@ int spcset(struct spcprm *spc)
  
    } else if (ptype == 'V') {
      if (strcmp(spc->type, "VELO") == 0) {
@@ -20137,7 +22058,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
        spc->flag = BETA;
        spc->spxP2S = velobeta;
        spc->spxS2P = betavelo;
-@@ -379,11 +376,11 @@ int spcset(struct spcprm *spc)
+@@ -379,11 +401,11 @@ int spcset(struct spcprm *spc)
    }
  
  
@@ -20152,7 +22073,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
      if (ptype == 'F') {
        spc->spxX2P = 0x0;
        spc->spxP2X = 0x0;
-@@ -404,7 +401,7 @@ int spcset(struct spcprm *spc)
+@@ -404,7 +426,7 @@ int spcset(struct spcprm *spc)
      spc->flag += F2S;
  
    } else if (xtype == 'W' || xtype == 'w') {
@@ -20161,7 +22082,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
      if (ptype == 'F') {
        spc->spxX2P = wavefreq;
        spc->spxP2X = freqwave;
-@@ -425,13 +422,13 @@ int spcset(struct spcprm *spc)
+@@ -425,13 +447,13 @@ int spcset(struct spcprm *spc)
      if (xtype == 'W') {
        spc->flag += W2S;
      } else {
@@ -20177,7 +22098,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
      if (ptype == 'F') {
        spc->spxX2P = awavfreq;
        spc->spxP2X = freqawav;
-@@ -452,13 +449,13 @@ int spcset(struct spcprm *spc)
+@@ -452,13 +474,13 @@ int spcset(struct spcprm *spc)
      if (xtype == 'A') {
        spc->flag += A2S;
      } else {
@@ -20193,7 +22114,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
      if (ptype == 'F') {
        spc->spxX2P = velofreq;
        spc->spxP2X = freqvelo;
-@@ -480,12 +477,12 @@ int spcset(struct spcprm *spc)
+@@ -480,12 +502,12 @@ int spcset(struct spcprm *spc)
    }
  
  
@@ -20209,7 +22130,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
      if (undefined(spc->pv[0])) spc->pv[0] = 0.0;
      if (undefined(spc->pv[1])) spc->pv[1] = 0.0;
      if (undefined(spc->pv[2])) spc->pv[2] = 0.0;
-@@ -494,7 +491,7 @@ int spcset(struct spcprm *spc)
+@@ -494,7 +516,7 @@ int spcset(struct spcprm *spc)
      if (undefined(spc->pv[5])) spc->pv[5] = 0.0;
      if (undefined(spc->pv[6])) spc->pv[6] = 0.0;
  
@@ -20218,7 +22139,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
      G       = spc->pv[0];
      m       = spc->pv[1];
      alpha   = spc->pv[2];
-@@ -518,7 +515,7 @@ int spcset(struct spcprm *spc)
+@@ -518,7 +540,7 @@ int spcset(struct spcprm *spc)
    return 0;
  }
  
@@ -20227,7 +22148,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
  
  int spcx2s(
    struct spcprm *spc,
-@@ -540,7 +537,7 @@ int spcx2s(
+@@ -540,7 +562,7 @@ int spcx2s(
    register double *specp;
    struct wcserr **err;
  
@@ -20236,7 +22157,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    if (spc == 0x0) return SPCERR_NULL_POINTER;
    err = &(spc->err);
  
-@@ -548,7 +545,7 @@ int spcx2s(
+@@ -548,7 +570,7 @@ int spcx2s(
      if ((status = spcset(spc))) return status;
    }
  
@@ -20245,7 +22166,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    xp = x;
    specp = spec;
    statp = stat;
-@@ -557,7 +554,7 @@ int spcx2s(
+@@ -557,7 +579,7 @@ int spcx2s(
      *(statp++) = 0;
    }
  
@@ -20254,7 +22175,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    if (spc->isGrism) {
      specp = spec;
      for (ix = 0; ix < nx; ix++, specp += sspec) {
-@@ -566,8 +563,8 @@ int spcx2s(
+@@ -566,8 +588,8 @@ int spcx2s(
      }
    }
  
@@ -20265,7 +22186,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    if (spc->spxX2P) {
      if ((statX2P = spc->spxX2P(spc->w[0], nx, sspec, sspec, spec, spec,
                                 stat))) {
-@@ -582,8 +579,8 @@ int spcx2s(
+@@ -582,8 +604,8 @@ int spcx2s(
      }
    }
  
@@ -20276,7 +22197,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    if (spc->spxP2S) {
      if ((statP2S = spc->spxP2S(spc->w[0], nx, sspec, sspec, spec, spec,
                                 stat))) {
-@@ -604,7 +601,7 @@ int spcx2s(
+@@ -604,7 +626,7 @@ int spcx2s(
    return status;
  }
  
@@ -20285,7 +22206,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
  
  int spcs2x(
    struct spcprm *spc,
-@@ -626,7 +623,7 @@ int spcs2x(
+@@ -626,7 +648,7 @@ int spcs2x(
    register double *xp;
    struct wcserr **err;
  
@@ -20294,7 +22215,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    if (spc == 0x0) return SPCERR_NULL_POINTER;
    err = &(spc->err);
  
-@@ -634,8 +631,8 @@ int spcs2x(
+@@ -634,8 +656,8 @@ int spcs2x(
      if ((status = spcset(spc))) return status;
    }
  
@@ -20305,7 +22226,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    if (spc->spxS2P) {
      if ((statS2P = spc->spxS2P(spc->w[0], nspec, sspec, sx, spec, x, stat))) {
        if (statS2P == SPXERR_BAD_INSPEC_COORD) {
-@@ -649,7 +646,7 @@ int spcs2x(
+@@ -649,7 +671,7 @@ int spcs2x(
      }
  
    } else {
@@ -20314,7 +22235,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
      xp = x;
      specp = spec;
      statp = stat;
-@@ -660,8 +657,8 @@ int spcs2x(
+@@ -660,8 +682,8 @@ int spcs2x(
    }
  
  
@@ -20325,7 +22246,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    if (spc->spxP2X) {
      if ((statP2X = spc->spxP2X(spc->w[0], nspec, sx, sx, x, x, stat))) {
        if (statP2X == SPCERR_BAD_SPEC) {
-@@ -676,7 +673,7 @@ int spcs2x(
+@@ -676,7 +698,7 @@ int spcs2x(
    }
  
    if (spc->isGrism) {
@@ -20334,7 +22255,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
      xp = x;
      statp = stat;
      for (ispec = 0; ispec < nspec; ispec++, xp += sx, statp++) {
-@@ -693,7 +690,7 @@ int spcs2x(
+@@ -693,7 +715,7 @@ int spcs2x(
    }
  
  
@@ -20343,7 +22264,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    xp = x;
    statp = stat;
    for (ispec = 0; ispec < nspec; ispec++, xp += sx) {
-@@ -709,7 +706,7 @@ int spcs2x(
+@@ -709,7 +731,7 @@ int spcs2x(
    return status;
  }
  
@@ -20352,7 +22273,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
  
  int spctyp(
    const char ctypei[9],
-@@ -726,7 +723,7 @@ int spctyp(
+@@ -726,7 +748,7 @@ int spctyp(
      ctypei, stype, scode, sname, units, ptype, xtype, restreq, NULL);
  }
  
@@ -20361,7 +22282,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
  
  int spctype(
    const char ctypei[9],
-@@ -747,11 +744,11 @@ int spctype(
+@@ -747,11 +769,11 @@ int spctype(
  
    if (err) *err = 0x0;
  
@@ -20375,7 +22296,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    if (strncmp(ctype, "FREQ", 4) == 0) {
      strcpy(sname_t, "Frequency");
      strcpy(units_t, "Hz");
-@@ -805,9 +802,9 @@ int spctype(
+@@ -805,9 +827,9 @@ int spctype(
    }
  
  
@@ -20387,7 +22308,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
      if (strcmp(ctype+4, "    ") != 0) {
        return wcserr_set(WCSERR_SET(SPCERR_BAD_SPEC_PARAMS),
          "Invalid spectral algorithm '%s'", ctype+4);
-@@ -820,21 +817,21 @@ int spctype(
+@@ -820,21 +842,21 @@ int spctype(
        "Invalid spectral type '%s'", ctype);
  
    } else if (strcmp(ctype+5, "LOG") == 0 || strcmp(ctype+5, "TAB") == 0) {
@@ -20414,7 +22335,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
        xtype_t = 'a';
      } else {
        return wcserr_set(WCSERR_SET(SPCERR_BAD_SPEC_PARAMS),
-@@ -842,22 +839,22 @@ int spctype(
+@@ -842,22 +864,22 @@ int spctype(
      }
  
    } else if (ctype[6] != '2') {
@@ -20441,7 +22362,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    if (strchr("FWAwa", (int)xtype_t)) {
      if (ptype_t == 'V') {
        restreq_t += 2;
-@@ -867,13 +864,13 @@ int spctype(
+@@ -867,13 +889,13 @@ int spctype(
        restreq_t += 2;
      }
    } else if (strchr("LT", (int)xtype_t) == 0) {
@@ -20457,7 +22378,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    if (stype) {
      memcpy(stype, ctype, 4);
      stype[4] = '\0';
-@@ -889,7 +886,7 @@ int spctype(
+@@ -889,7 +911,7 @@ int spctype(
    return 0;
  }
  
@@ -20466,7 +22387,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
  
  int spcspx(
    const char ctypeS[9],
-@@ -907,7 +904,7 @@ int spcspx(
+@@ -907,7 +929,7 @@ int spcspx(
                   crvalX, dXdS, 0x0);
  }
  
@@ -20475,7 +22396,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
  
  int spcspxe(
    const char ctypeS[9],
-@@ -930,25 +927,25 @@ int spcspxe(
+@@ -930,25 +952,25 @@ int spcspxe(
    struct spxprm spx;
  
  
@@ -20505,7 +22426,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    strcpy(type, stype);
    spx.err = (err ? *err : 0x0);
    if ((status = specx(type, crvalS, restfrq, restwav, &spx))) {
-@@ -964,7 +961,7 @@ int spcspxe(
+@@ -964,7 +986,7 @@ int spcspxe(
    }
  
  
@@ -20514,7 +22435,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    dPdS = 0.0;
    dXdP = 0.0;
    if (*ptype == 'F') {
-@@ -1063,7 +1060,7 @@ int spcspxe(
+@@ -1063,7 +1085,7 @@ int spcspxe(
    return 0;
  }
  
@@ -20523,7 +22444,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
  
  int spcxps(
    const char ctypeS[9],
-@@ -1081,7 +1078,7 @@ int spcxps(
+@@ -1081,7 +1103,7 @@ int spcxps(
                   crvalS, dSdX, NULL);
  }
  
@@ -20532,7 +22453,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
  
  int spcxpse(
    const char ctypeS[9],
-@@ -1103,25 +1100,25 @@ int spcxpse(
+@@ -1103,25 +1125,25 @@ int spcxpse(
    double dPdX, dSdP;
    struct spxprm spx;
  
@@ -20562,7 +22483,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    if (*xtype == 'F') {
      strcpy(type, "FREQ");
    } else if (*xtype == 'W' || *xtype == 'w') {
-@@ -1146,7 +1143,7 @@ int spcxpse(
+@@ -1146,7 +1168,7 @@ int spcxpse(
    }
  
  
@@ -20571,7 +22492,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    dPdX = 0.0;
    dSdP = 0.0;
    if (*ptype == 'F') {
-@@ -1240,7 +1237,7 @@ int spcxpse(
+@@ -1240,7 +1262,7 @@ int spcxpse(
    return 0;
  }
  
@@ -20580,7 +22501,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
  
  int spctrn(
    const char ctypeS1[9],
-@@ -1257,7 +1254,7 @@ int spctrn(
+@@ -1257,7 +1279,7 @@ int spctrn(
                   ctypeS2, crvalS2, cdeltS2, NULL);
  }
  
@@ -20589,7 +22510,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
  
  int spctrne(
    const char ctypeS1[9],
-@@ -1278,9 +1275,9 @@ int spctrne(
+@@ -1278,9 +1300,9 @@ int spctrne(
    double crvalX, dS2dX, dXdS1;
  
    if (restfrq == 0.0 && restwav == 0.0) {
@@ -20602,7 +22523,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
      strncpy(stype1, ctypeS1, 4);
      strncpy(stype2, ctypeS2, 4);
      stype1[4] = stype2[4] = '\0';
-@@ -1295,13 +1292,13 @@ int spctrne(
+@@ -1295,13 +1317,13 @@ int spctrne(
      return status;
    }
  
@@ -20618,7 +22539,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
      if (xtype1 == 'w') {
        strcpy(ctypeS2+5, "GRI");
      } else if (xtype1 == 'a') {
-@@ -1317,7 +1314,7 @@ int spctrne(
+@@ -1317,7 +1339,7 @@ int spctrne(
      return status;
    }
  
@@ -20627,7 +22548,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
    if (xtype2 != xtype1) {
      return wcserr_set(WCSERR_SET(SPCERR_BAD_SPEC_PARAMS),
        "Incompatible X-types '%c' and '%c'", xtype1, xtype2);
-@@ -1336,7 +1333,7 @@ int spctrne(
+@@ -1336,7 +1358,7 @@ int spctrne(
    return 0;
  }
  
@@ -20636,7 +22557,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
  
  int spcaips(
    const char ctypeA[9],
-@@ -1350,18 +1347,18 @@ int spcaips(
+@@ -1350,18 +1372,18 @@ int spcaips(
    char *fcode;
    int  ivf, status;
  
@@ -20658,7 +22579,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
      if (*(fcode = ctype+4)) {
        if (strcmp(fcode, "-LSR") == 0) {
          strcpy(specsys, "LSRK");
-@@ -1370,7 +1367,7 @@ int spcaips(
+@@ -1370,7 +1392,7 @@ int spcaips(
        } else if (strcmp(fcode, "-OBS") == 0) {
          strcpy(specsys, "TOPOCENT");
        } else {
@@ -20667,7 +22588,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
          return SPCERR_NO_CHANGE;
        }
  
-@@ -1378,7 +1375,7 @@ int spcaips(
+@@ -1378,7 +1400,7 @@ int spcaips(
        status = 0;
      }
  
@@ -20676,7 +22597,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
      ivf = velref%256;
      if (0 < ivf && ivf <= 7) {
        strcpy(specsys, frames[ivf-1]);
-@@ -1388,9 +1385,9 @@ int spcaips(
+@@ -1388,9 +1410,9 @@ int spcaips(
      }
  
      if (strcmp(ctype, "VELO") == 0) {
@@ -20688,7 +22609,7 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
          ivf = velref/256;
          if (ivf == 0) {
            strcpy(ctype, "VOPT");
-@@ -1401,8 +1398,8 @@ int spcaips(
+@@ -1401,8 +1423,8 @@ int spcaips(
          }
        }
      } else if (strcmp(ctype, "FELO") == 0) {
@@ -20699,16 +22620,16 @@ Index: astropy-4.2/cextern/wcslib/C/spc.c
        strcpy(ctype, "VOPT-F2W");
        if (status < 0) status = 0;
      }
-Index: astropy-4.2/cextern/wcslib/C/spc.h
+Index: astropy-4.2.1/cextern/wcslib/C/spc.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/spc.h
-+++ astropy-4.2/cextern/wcslib/C/spc.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/spc.h
++++ astropy-4.2.1/cextern/wcslib/C/spc.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -20722,15 +22643,59 @@ Index: astropy-4.2/cextern/wcslib/C/spc.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: spc.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: spc.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: spc.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
-@@ -794,67 +791,67 @@ extern "C" {
+@@ -52,7 +49,8 @@
+ *
+ * Routine spcini() is provided to initialize the spcprm struct with default
+ * values, spcfree() reclaims any memory that may have been allocated to store
+-* an error message, and spcprt() prints its contents.
++* an error message, spcsize() computes its total size including allocated
++* memory, and spcprt() prints its contents.
+ *
+ * spcperr() prints the error message(s) (if any) stored in a spcprm struct.
+ *
+@@ -213,6 +211,33 @@
+ *                         1: Null spcprm pointer passed.
+ *
+ *
++* spcsize() - Compute the size of a spcprm struct
++* -----------------------------------------------
++* spcsize() computes the full size of a spcprm struct, including allocated
++* memory.
++*
++* Given:
++*   spc       const struct spcprm*
++*                       Spectral transformation parameters.
++*
++*                       If NULL, the base size of the struct and the allocated
++*                       size are both set to zero.
++*
++* Returned:
++*   sizes     int[2]    The first element is the base size of the struct as
++*                       returned by sizeof(struct spcprm).  The second element
++*                       is the total allocated size, in bytes.  This figure
++*                       includes memory allocated for the constituent struct,
++*                       spcprm::err.
++*
++*                       It is not an error for the struct not to have been set
++*                       up via spcset().
++*
++* Function return value:
++*             int       Status return value:
++*                         0: Success.
++*
++*
+ * spcprt() - Print routine for the spcprm struct
+ * ----------------------------------------------
+ * spcprt() prints the contents of a spcprm struct using wcsprintf().  Mainly
+@@ -794,67 +819,67 @@ extern "C" {
  extern const char *spc_errmsg[];
  
  enum spc_errmsg_enum {
@@ -20850,7 +22815,16 @@ Index: astropy-4.2/cextern/wcslib/C/spc.h
  #define SPCLEN (sizeof(struct spcprm)/sizeof(int))
  
  
-@@ -893,7 +890,7 @@ int spctrne(const char ctypeS1[9], doubl
+@@ -862,6 +887,8 @@ int spcini(struct spcprm *spc);
+ 
+ int spcfree(struct spcprm *spc);
+ 
++int spcsize(const struct spcprm *spc, int sizes[2]);
++
+ int spcprt(const struct spcprm *spc);
+ 
+ int spcperr(const struct spcprm *spc, const char *prefix);
+@@ -893,7 +920,7 @@ int spctrne(const char ctypeS1[9], doubl
  int spcaips(const char ctypeA[9], int velref, char ctype[9], char specsys[9]);
  
  
@@ -20859,22 +22833,22 @@ Index: astropy-4.2/cextern/wcslib/C/spc.h
  #define spcini_errmsg spc_errmsg
  #define spcprt_errmsg spc_errmsg
  #define spcset_errmsg spc_errmsg
-@@ -916,4 +913,4 @@ int spctrn(const char ctypeS1[9], double
+@@ -916,4 +943,4 @@ int spctrn(const char ctypeS1[9], double
  }
  #endif
  
 -#endif /* WCSLIB_SPC */
 +#endif // WCSLIB_SPC
-Index: astropy-4.2/cextern/wcslib/C/sph.c
+Index: astropy-4.2.1/cextern/wcslib/C/sph.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/sph.c
-+++ astropy-4.2/cextern/wcslib/C/sph.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/sph.c
++++ astropy-4.2.1/cextern/wcslib/C/sph.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -20888,7 +22862,7 @@ Index: astropy-4.2/cextern/wcslib/C/sph.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: sph.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: sph.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: sph.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <math.h>
@@ -21194,16 +23168,16 @@ Index: astropy-4.2/cextern/wcslib/C/sph.c
    sphx2s(eul, nfield, 0, 1, 1, lng, lat, lng, lat);
  
    return 0;
-Index: astropy-4.2/cextern/wcslib/C/sph.h
+Index: astropy-4.2.1/cextern/wcslib/C/sph.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/sph.h
-+++ astropy-4.2/cextern/wcslib/C/sph.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/sph.h
++++ astropy-4.2.1/cextern/wcslib/C/sph.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -21217,11 +23191,11 @@ Index: astropy-4.2/cextern/wcslib/C/sph.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: sph.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: sph.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: sph.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
@@ -21325,16 +23299,16 @@ Index: astropy-4.2/cextern/wcslib/C/sph.h
  
 -#endif /* WCSLIB_SPH */
 +#endif // WCSLIB_SPH
-Index: astropy-4.2/cextern/wcslib/C/spx.c
+Index: astropy-4.2.1/cextern/wcslib/C/spx.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/spx.c
-+++ astropy-4.2/cextern/wcslib/C/spx.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/spx.c
++++ astropy-4.2.1/cextern/wcslib/C/spx.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -21348,7 +23322,7 @@ Index: astropy-4.2/cextern/wcslib/C/spx.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: spx.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: spx.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: spx.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <math.h>
@@ -21678,16 +23652,16 @@ Index: astropy-4.2/cextern/wcslib/C/spx.c
    (void)dummy;
  
    betap = beta;
-Index: astropy-4.2/cextern/wcslib/C/spx.h
+Index: astropy-4.2.1/cextern/wcslib/C/spx.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/spx.h
-+++ astropy-4.2/cextern/wcslib/C/spx.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/spx.h
++++ astropy-4.2.1/cextern/wcslib/C/spx.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -21701,11 +23675,11 @@ Index: astropy-4.2/cextern/wcslib/C/spx.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: spx.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: spx.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: spx.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
@@ -21829,16 +23803,16 @@ Index: astropy-4.2/cextern/wcslib/C/spx.h
  
 -#endif /* WCSLIB_SPEC */
 +#endif // WCSLIB_SPEC
-Index: astropy-4.2/cextern/wcslib/C/tab.c
+Index: astropy-4.2.1/cextern/wcslib/C/tab.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/tab.c
-+++ astropy-4.2/cextern/wcslib/C/tab.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/tab.c
++++ astropy-4.2.1/cextern/wcslib/C/tab.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -21852,7 +23826,7 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: tab.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: tab.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: tab.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <math.h>
@@ -21865,7 +23839,7 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
  const char *tab_errmsg[] = {
    "Success",
    "Null tabprm pointer passed",
-@@ -47,10 +44,10 @@ const char *tab_errmsg[] = {
+@@ -47,27 +44,23 @@ const char *tab_errmsg[] = {
    "One or more of the x coordinates were invalid",
    "One or more of the world coordinates were invalid"};
  
@@ -21878,8 +23852,13 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
  
  int tabini(int alloc, int M, const int K[], struct tabprm *tab)
  
-@@ -63,7 +60,7 @@ int tabini(int alloc, int M, const int K
+ {
+   static const char *function = "tabini";
  
+-  int k, m, N;
+-  double *dp;
+-  struct wcserr **err;
+-
    if (tab == 0x0) return TABERR_NULL_POINTER;
  
 -  /* Initialize error message handling. */
@@ -21887,16 +23866,27 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
    if (tab->flag == -1) {
      tab->err = 0x0;
    }
-@@ -76,7 +73,7 @@ int tabini(int alloc, int M, const int K
+-  err = &(tab->err);
++  struct wcserr **err = &(tab->err);
+   wcserr_clear(err);
+ 
+ 
+@@ -76,11 +69,12 @@ int tabini(int alloc, int M, const int K
        "M must be positive, got %d", M);
    }
  
 -  /* Determine the total number of elements in the coordinate array. */
 +  // Determine the total number of elements in the coordinate array.
++  int N;
    if (K) {
      N = M;
  
-@@ -91,12 +88,12 @@ int tabini(int alloc, int M, const int K
+-    for (m = 0; m < M; m++) {
++    for (int m = 0; m < M; m++) {
+       if (K[m] < 0) {
+         return wcserr_set(WCSERR_SET(TABERR_BAD_PARAMS),
+           "Invalid tabular parameters: Each element of K must be "
+@@ -91,12 +85,12 @@ int tabini(int alloc, int M, const int K
      }
  
    } else {
@@ -21911,16 +23901,18 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
    if (tab->flag == -1 || tab->m_flag != TABSET) {
      if (tab->flag == -1) {
        tab->sense   = 0x0;
-@@ -117,7 +114,7 @@ int tabini(int alloc, int M, const int K
+@@ -117,8 +111,8 @@ int tabini(int alloc, int M, const int K
      tab->m_coord = 0x0;
  
    } else {
 -    /* Clear any outstanding signals set by wcstab(). */
+-    for (m = 0; m < tab->m_M; m++) {
 +    // Clear any outstanding signals set by wcstab().
-     for (m = 0; m < tab->m_M; m++) {
++    for (int m = 0; m < tab->m_M; m++) {
        if (tab->m_indxs[m] == (double *)0x1) tab->m_indxs[m] = 0x0;
      }
-@@ -126,7 +123,7 @@ int tabini(int alloc, int M, const int K
+ 
+@@ -126,7 +120,7 @@ int tabini(int alloc, int M, const int K
    }
  
  
@@ -21929,7 +23921,7 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
    if (alloc ||
       tab->K == 0x0 ||
       tab->map == 0x0 ||
-@@ -134,15 +131,15 @@ int tabini(int alloc, int M, const int K
+@@ -134,15 +128,15 @@ int tabini(int alloc, int M, const int K
       tab->index == 0x0 ||
       tab->coord == 0x0) {
  
@@ -21948,7 +23940,7 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
          tab->K = tab->m_K;
  
        } else {
-@@ -158,7 +155,7 @@ int tabini(int alloc, int M, const int K
+@@ -158,7 +152,7 @@ int tabini(int alloc, int M, const int K
  
      if (alloc || tab->map == 0x0) {
        if (tab->m_map) {
@@ -21957,7 +23949,7 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
          tab->map = tab->m_map;
  
        } else {
-@@ -174,7 +171,7 @@ int tabini(int alloc, int M, const int K
+@@ -174,7 +168,7 @@ int tabini(int alloc, int M, const int K
  
      if (alloc || tab->crval == 0x0) {
        if (tab->m_crval) {
@@ -21966,7 +23958,7 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
          tab->crval = tab->m_crval;
  
        } else {
-@@ -190,7 +187,7 @@ int tabini(int alloc, int M, const int K
+@@ -190,7 +184,7 @@ int tabini(int alloc, int M, const int K
  
      if (alloc || tab->index == 0x0) {
        if (tab->m_index) {
@@ -21975,16 +23967,19 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
          tab->index = tab->m_index;
  
        } else {
-@@ -207,7 +204,7 @@ int tabini(int alloc, int M, const int K
+@@ -207,9 +201,9 @@ int tabini(int alloc, int M, const int K
            return wcserr_set(TAB_ERRMSG(TABERR_MEMORY));
          }
  
 -        /* Recall that calloc() initializes these pointers to zero. */
 +        // Recall that calloc() initializes these pointers to zero.
          if (K) {
-           for (m = 0; m < M; m++) {
+-          for (m = 0; m < M; m++) {
++          for (int m = 0; m < M; m++) {
              if (K[m]) {
-@@ -224,7 +221,7 @@ int tabini(int alloc, int M, const int K
+               if (!(tab->index[m] = calloc(K[m], sizeof(double)))) {
+                 return wcserr_set(TAB_ERRMSG(TABERR_MEMORY));
+@@ -224,7 +218,7 @@ int tabini(int alloc, int M, const int K
  
      if (alloc || tab->coord == 0x0) {
        if (tab->m_coord) {
@@ -21993,25 +23988,37 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
          tab->coord = tab->m_coord;
  
        } else if (N) {
-@@ -243,7 +240,7 @@ int tabini(int alloc, int M, const int K
+@@ -243,15 +237,16 @@ int tabini(int alloc, int M, const int K
    tab->flag = 0;
    tab->M = M;
  
 -  /* Set defaults. */
+-  for (m = 0; m < M; m++) {
 +  // Set defaults.
-   for (m = 0; m < M; m++) {
++  for (int m = 0; m < M; m++) {
      tab->map[m] = -1;
      tab->crval[m] = 0.0;
-@@ -260,7 +257,7 @@ int tabini(int alloc, int M, const int K
+ 
+     if (K) {
+       tab->K[m] = K[m];
++      double *dp;
+       if ((dp = tab->index[m])) {
+-        for (k = 0; k < K[m]; k++) {
++        for (int k = 0; k < K[m]; k++) {
+           *(dp++) = k;
+         }
+       }
+@@ -260,36 +255,34 @@ int tabini(int alloc, int M, const int K
      }
    }
  
 -  /* Initialize the coordinate array. */
+-  for (dp = tab->coord; dp < tab->coord + N; dp++) {
 +  // Initialize the coordinate array.
-   for (dp = tab->coord; dp < tab->coord + N; dp++) {
++  for (double *dp = tab->coord; dp < tab->coord + N; dp++) {
      *dp = UNDEFINED;
    }
-@@ -268,7 +265,7 @@ int tabini(int alloc, int M, const int K
+ 
    return 0;
  }
  
@@ -22020,8 +24027,15 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
  
  int tabmem(struct tabprm *tab)
  
-@@ -282,7 +279,7 @@ int tabmem(struct tabprm *tab)
-   err = &(tab->err);
+ {
+   static const char *function = "tabmem";
+ 
+-  int m, M, N;
+-  struct wcserr **err;
+-
+   if (tab == 0x0) return TABERR_NULL_POINTER;
+-  err = &(tab->err);
++  struct wcserr **err = &(tab->err);
  
    if (tab->M == 0 || tab->K == 0x0) {
 -    /* Should have been set by this time. */
@@ -22029,7 +24043,17 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
      return wcserr_set(WCSERR_SET(TABERR_MEMORY),
        "Null pointers in tabprm struct");
    }
-@@ -303,7 +300,7 @@ int tabmem(struct tabprm *tab)
+ 
+ 
+-  N = M = tab->M;
+-  for (m = 0; m < M; m++) {
++  int M = tab->M;
++  int N = tab->M;
++  for (int m = 0; m < M; m++) {
+     if (tab->K[m] < 0) {
+       return wcserr_set(WCSERR_SET(TABERR_BAD_PARAMS),
+         "Invalid tabular parameters: Each element of K must be "
+@@ -303,7 +296,7 @@ int tabmem(struct tabprm *tab)
    if (tab->m_M == 0) {
      tab->m_M = M;
    } else if (tab->m_M < M) {
@@ -22038,7 +24062,7 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
      return wcserr_set(WCSERR_SET(TABERR_MEMORY),
        "tabprm struct inconsistent");
    }
-@@ -311,7 +308,7 @@ int tabmem(struct tabprm *tab)
+@@ -311,7 +304,7 @@ int tabmem(struct tabprm *tab)
    if (tab->m_N == 0) {
      tab->m_N = N;
    } else if (tab->m_N < N) {
@@ -22047,7 +24071,16 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
      return wcserr_set(WCSERR_SET(TABERR_MEMORY),
        "tabprm struct inconsistent");
    }
-@@ -359,7 +356,7 @@ int tabmem(struct tabprm *tab)
+@@ -340,7 +333,7 @@ int tabmem(struct tabprm *tab)
+     }
+   }
+ 
+-  for (m = 0; m < tab->m_M; m++) {
++  for (int m = 0; m < tab->m_M; m++) {
+     if (tab->m_indxs[m] == 0x0 || tab->m_indxs[m] == (double *)0x1) {
+       if ((tab->m_indxs[m] = tab->index[m])) {
+         tab->m_flag = TABSET;
+@@ -359,22 +352,20 @@ int tabmem(struct tabprm *tab)
    return 0;
  }
  
@@ -22056,7 +24089,56 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
  
  int tabcpy(int alloc, const struct tabprm *tabsrc, struct tabprm *tabdst)
  
-@@ -409,7 +406,7 @@ int tabcpy(int alloc, const struct tabpr
+ {
+   static const char *function = "tabcpy";
+ 
+-  int k, m, M, n, N, status;
+-  double *dstp, *srcp;
+-  struct wcserr **err;
++  int status;
+ 
+   if (tabsrc == 0x0) return TABERR_NULL_POINTER;
+   if (tabdst == 0x0) return TABERR_NULL_POINTER;
+-  err = &(tabdst->err);
++  struct wcserr **err = &(tabdst->err);
+ 
+-  M = tabsrc->M;
++  int M = tabsrc->M;
+   if (M <= 0) {
+     return wcserr_set(WCSERR_SET(TABERR_BAD_PARAMS),
+       "M must be positive, got %d", M);
+@@ -384,17 +375,18 @@ int tabcpy(int alloc, const struct tabpr
+     return status;
+   }
+ 
+-  N = M;
+-  for (m = 0; m < M; m++) {
++  int N = M;
++  for (int m = 0; m < M; m++) {
+     tabdst->map[m]   = tabsrc->map[m];
+     tabdst->crval[m] = tabsrc->crval[m];
+     N *= tabsrc->K[m];
+   }
+ 
+-  for (m = 0; m < M; m++) {
++  double *dstp, *srcp;
++  for (int m = 0; m < M; m++) {
+     if ((srcp = tabsrc->index[m])) {
+       dstp = tabdst->index[m];
+-      for (k = 0; k < tabsrc->K[m]; k++) {
++      for (int k = 0; k < tabsrc->K[m]; k++) {
+         *(dstp++) = *(srcp++);
+       }
+     }
+@@ -402,14 +394,14 @@ int tabcpy(int alloc, const struct tabpr
+ 
+   srcp = tabsrc->coord;
+   dstp = tabdst->coord;
+-  for (n = 0; n < N; n++) {
++  for (int n = 0; n < N; n++) {
+     *(dstp++) = *(srcp++);
+   }
+ 
    return 0;
  }
  
@@ -22065,16 +24147,49 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
  
  int tabcmp(
    int dummy,
-@@ -421,7 +418,7 @@ int tabcmp(
- {
-   int m, M, N;
+@@ -419,9 +411,7 @@ int tabcmp(
+   int *equal)
  
+ {
+-  int m, M, N;
+-
 -  /* Avert nuisance compiler warnings about unused parameters. */
 +  // Avert nuisance compiler warnings about unused parameters.
    (void)dummy;
  
    if (tab1  == 0x0) return TABERR_NULL_POINTER;
-@@ -461,7 +458,7 @@ int tabcmp(
+@@ -434,24 +424,24 @@ int tabcmp(
+     return 0;
+   }
+ 
+-  M = tab1->M;
++  int M = tab1->M;
+ 
+   if (!wcsutil_intEq(M, tab1->K, tab2->K) ||
+       !wcsutil_intEq(M, tab1->map, tab2->map) ||
+-      !wcsutil_Eq(M, tol, tab1->crval, tab2->crval)) {
++      !wcsutil_dblEq(M, tol, tab1->crval, tab2->crval)) {
+     return 0;
+   }
+ 
+-  N = M;
+-  for (m = 0; m < M; m++) {
+-    if (!wcsutil_Eq(tab1->K[m], tol, tab1->index[m], tab2->index[m])) {
++  int N = M;
++  for (int m = 0; m < M; m++) {
++    if (!wcsutil_dblEq(tab1->K[m], tol, tab1->index[m], tab2->index[m])) {
+       return 0;
+     }
+ 
+     N *= tab1->K[m];
+   }
+ 
+-  if (!wcsutil_Eq(N, tol, tab1->coord, tab2->coord)) {
++  if (!wcsutil_dblEq(N, tol, tab1->coord, tab2->coord)) {
+     return 0;
+   }
+ 
+@@ -461,24 +451,22 @@ int tabcmp(
  }
  
  
@@ -22083,13 +24198,16 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
  
  int tabfree(struct tabprm *tab)
  
-@@ -471,14 +468,14 @@ int tabfree(struct tabprm *tab)
+ {
+-  int m;
+-
    if (tab == 0x0) return TABERR_NULL_POINTER;
  
    if (tab->flag != -1) {
 -    /* Clear any outstanding signals set by wcstab(). */
+-    for (m = 0; m < tab->m_M; m++) {
 +    // Clear any outstanding signals set by wcstab().
-     for (m = 0; m < tab->m_M; m++) {
++    for (int m = 0; m < tab->m_M; m++) {
        if (tab->m_indxs[m] == (double *)0x1) tab->m_indxs[m] = 0x0;
      }
  
@@ -22100,7 +24218,16 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
      if (tab->m_flag == TABSET) {
        if (tab->K     == tab->m_K)     tab->K = 0x0;
        if (tab->map   == tab->m_map)   tab->map = 0x0;
-@@ -501,7 +498,7 @@ int tabfree(struct tabprm *tab)
+@@ -491,7 +479,7 @@ int tabfree(struct tabprm *tab)
+       if (tab->m_crval) free(tab->m_crval);
+ 
+       if (tab->m_index) {
+-        for (m = 0; m < tab->m_M; m++) {
++        for (int m = 0; m < tab->m_M; m++) {
+           if (tab->m_indxs[m]) free(tab->m_indxs[m]);
+         }
+         free(tab->m_index);
+@@ -501,7 +489,7 @@ int tabfree(struct tabprm *tab)
        if (tab->m_coord) free(tab->m_coord);
      }
  
@@ -22109,16 +24236,92 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
      if (tab->sense)   free(tab->sense);
      if (tab->p0)      free(tab->p0);
      if (tab->delta)   free(tab->delta);
-@@ -531,7 +528,7 @@ int tabfree(struct tabprm *tab)
+@@ -531,13 +519,82 @@ int tabfree(struct tabprm *tab)
    return 0;
  }
  
 -/*--------------------------------------------------------------------------*/
++//----------------------------------------------------------------------------
++
++int tabsize(const struct tabprm *tab, int sizes[2])
++
++{
++  if (tab == 0x0) {
++    sizes[0] = sizes[1] = 0;
++    return TABERR_SUCCESS;
++  }
++
++  // Base size, in bytes.
++  sizes[0] = sizeof(struct tabprm);
++
++  // Total size of allocated memory, in bytes.
++  sizes[1] = 0;
++
++  int exsizes[2];
++  int M = tab->M;
++
++  // tabprm::K[];
++  sizes[1] += M * sizeof(int);
++
++  // tabprm::map[];
++  sizes[1] += M * sizeof(int);
++
++  // tabprm::crval[];
++  sizes[1] += M * sizeof(double);
++
++  // tabprm::index[] and tabprm::m_indxs;
++  sizes[1] += 2*M * sizeof(double *);
++  for (int m = 0; m < M; m++) {
++    if (tab->index[m]) {
++      sizes[1] += tab->K[m] * sizeof(double);
++    }
++  }
++
++  // tabprm::coord[];
++  sizes[1] += M * tab->nc * sizeof(double);
++
++  // tab::err[].
++  wcserr_size(tab->err, exsizes);
++  sizes[1] += exsizes[0] + exsizes[1];
++
++  // The remaining arrays are allocated by tabset().
++  if (tab->flag != TABSET) {
++    return TABERR_SUCCESS;
++  }
++
++  // tabprm::sense[].
++  if (tab->sense) {
++    sizes[1] += M * sizeof(int);
++  }
++
++  // tabprm::p0[].
++  if (tab->p0) {
++    sizes[1] += M * sizeof(int);
++  }
++
++  // tabprm::delta[].
++  if (tab->delta) {
++    sizes[1] += M * sizeof(double);
++  }
++
++  // tabprm::extrema[].
++  int ne = (tab->nc / tab->K[0]) * 2 * M;
++  sizes[1] += ne * sizeof(double);
++
++  return TABERR_SUCCESS;
++}
++
 +//----------------------------------------------------------------------------
  
  int tabprt(const struct tabprm *tab)
  
-@@ -550,7 +547,7 @@ int tabprt(const struct tabprm *tab)
+ {
+   char   *cp, text[128];
+-  int    j, k, m, n, nd;
+   double *dp;
+ 
+   if (tab == 0x0) return TABERR_NULL_POINTER;
+@@ -550,37 +607,37 @@ int tabprt(const struct tabprm *tab)
    wcsprintf("       flag: %d\n", tab->flag);
    wcsprintf("          M: %d\n", tab->M);
  
@@ -22126,8 +24329,9 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
 +  // Array dimensions.
    WCSPRINTF_PTR("          K: ", tab->K, "\n");
    wcsprintf("            ");
-   for (m = 0; m < tab->M; m++) {
-@@ -558,7 +555,7 @@ int tabprt(const struct tabprm *tab)
+-  for (m = 0; m < tab->M; m++) {
++  for (int m = 0; m < tab->M; m++) {
+     wcsprintf("%6d", tab->K[m]);
    }
    wcsprintf("\n");
  
@@ -22135,8 +24339,9 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
 +  // Map vector.
    WCSPRINTF_PTR("        map: ", tab->map, "\n");
    wcsprintf("            ");
-   for (m = 0; m < tab->M; m++) {
-@@ -566,7 +563,7 @@ int tabprt(const struct tabprm *tab)
+-  for (m = 0; m < tab->M; m++) {
++  for (int m = 0; m < tab->M; m++) {
+     wcsprintf("%6d", tab->map[m]);
    }
    wcsprintf("\n");
  
@@ -22144,17 +24349,26 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
 +  // Reference index value.
    WCSPRINTF_PTR("      crval: ", tab->crval, "\n");
    wcsprintf("            ");
-   for (m = 0; m < tab->M; m++) {
-@@ -574,7 +571,7 @@ int tabprt(const struct tabprm *tab)
+-  for (m = 0; m < tab->M; m++) {
++  for (int m = 0; m < tab->M; m++) {
+     wcsprintf("  %#- 11.5g", tab->crval[m]);
    }
    wcsprintf("\n");
  
 -  /* Index vectors. */
 +  // Index vectors.
    WCSPRINTF_PTR("      index: ", tab->index, "\n");
-   for (m = 0; m < tab->M; m++) {
+-  for (m = 0; m < tab->M; m++) {
++  for (int m = 0; m < tab->M; m++) {
      wcsprintf("   index[%d]: ", m);
-@@ -590,11 +587,11 @@ int tabprt(const struct tabprm *tab)
+     WCSPRINTF_PTR("", tab->index[m], "");
+     if (tab->index[m]) {
+-      for (k = 0; k < tab->K[m]; k++) {
++      for (int k = 0; k < tab->K[m]; k++) {
+         if (k%5 == 0) {
+           wcsprintf("\n            ");
+         }
+@@ -590,22 +647,22 @@ int tabprt(const struct tabprm *tab)
      }
    }
  
@@ -22162,22 +24376,83 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
 +  // Coordinate array.
    WCSPRINTF_PTR("      coord: ", tab->coord, "\n");
    dp = tab->coord;
-   for (n = 0; n < tab->nc; n++) {
+-  for (n = 0; n < tab->nc; n++) {
 -    /* Array index. */
+-    j = n;
++  for (int n = 0; n < tab->nc; n++) {
 +    // Array index.
-     j = n;
++    int j = n;
      cp = text;
-     for (m = 0; m < tab->M; m++) {
-@@ -643,7 +640,7 @@ int tabprt(const struct tabprm *tab)
+-    for (m = 0; m < tab->M; m++) {
+-      nd = (tab->K[m] < 10) ? 1 : 2;
++    for (int m = 0; m < tab->M; m++) {
++      int nd = (tab->K[m] < 10) ? 1 : 2;
+       sprintf(cp, ",%*d", nd, j % tab->K[m] + 1);
+       j /= tab->K[m];
+       cp += strlen(cp);
+     }
+ 
+     wcsprintf("             (*%s)", text);
+-    for (m = 0; m < tab->M; m++) {
++    for (int m = 0; m < tab->M; m++) {
+       wcsprintf("  %#- 11.5g", *(dp++));
+     }
+     wcsprintf("\n");
+@@ -616,7 +673,7 @@ int tabprt(const struct tabprm *tab)
+   WCSPRINTF_PTR("      sense: ", tab->sense, "\n");
+   if (tab->sense) {
+     wcsprintf("            ");
+-    for (m = 0; m < tab->M; m++) {
++    for (int m = 0; m < tab->M; m++) {
+       wcsprintf("%6d", tab->sense[m]);
+     }
+     wcsprintf("\n");
+@@ -625,7 +682,7 @@ int tabprt(const struct tabprm *tab)
+   WCSPRINTF_PTR("         p0: ", tab->p0, "\n");
+   if (tab->p0) {
+     wcsprintf("            ");
+-    for (m = 0; m < tab->M; m++) {
++    for (int m = 0; m < tab->M; m++) {
+       wcsprintf("%6d", tab->p0[m]);
+     }
+     wcsprintf("\n");
+@@ -634,7 +691,7 @@ int tabprt(const struct tabprm *tab)
+   WCSPRINTF_PTR("      delta: ", tab->delta, "\n");
+   if (tab->delta) {
+     wcsprintf("            ");
+-    for (m = 0; m < tab->M; m++) {
++    for (int m = 0; m < tab->M; m++) {
+       wcsprintf("  %#- 11.5g", tab->delta[m]);
+     }
+     wcsprintf("\n");
+@@ -642,20 +699,20 @@ int tabprt(const struct tabprm *tab)
+ 
    WCSPRINTF_PTR("    extrema: ", tab->extrema, "\n");
    dp = tab->extrema;
-   for (n = 0; n < tab->nc/tab->K[0]; n++) {
+-  for (n = 0; n < tab->nc/tab->K[0]; n++) {
 -    /* Array index. */
+-    j = n;
++  for (int n = 0; n < tab->nc/tab->K[0]; n++) {
 +    // Array index.
-     j = n;
++    int j = n;
      cp = text;
      *cp = '\0';
-@@ -667,7 +664,7 @@ int tabprt(const struct tabprm *tab)
+-    for (m = 1; m < tab->M; m++) {
+-      nd = (tab->K[m] < 10) ? 1 : 2;
++    for (int m = 1; m < tab->M; m++) {
++      int nd = (tab->K[m] < 10) ? 1 : 2;
+       sprintf(cp, ",%*d", nd, j % tab->K[m] + 1);
+       j /= tab->K[m];
+       cp += strlen(cp);
+     }
+ 
+     wcsprintf("             (*,*%s)", text);
+-    for (m = 0; m < 2*tab->M; m++) {
++    for (int m = 0; m < 2*tab->M; m++) {
+       if (m == tab->M) wcsprintf("->  ");
+       wcsprintf("  %#- 11.5g", *(dp++));
+     }
+@@ -667,7 +724,7 @@ int tabprt(const struct tabprm *tab)
      wcserr_prt(tab->err, "             ");
    }
  
@@ -22186,7 +24461,16 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
    wcsprintf("     m_flag: %d\n", tab->m_flag);
    wcsprintf("        m_M: %d\n", tab->m_M);
    wcsprintf("        m_N: %d\n", tab->m_N);
-@@ -701,7 +698,7 @@ int tabprt(const struct tabprm *tab)
+@@ -687,7 +744,7 @@ int tabprt(const struct tabprm *tab)
+   WCSPRINTF_PTR("    m_index: ", tab->m_index, "");
+   if (tab->m_index == tab->index) wcsprintf("  (= index)");
+   wcsprintf("\n");
+-  for (m = 0; m < tab->M; m++) {
++  for (int m = 0; m < tab->M; m++) {
+     wcsprintf(" m_indxs[%d]: ", m);
+     WCSPRINTF_PTR("", tab->m_indxs[m], "");
+     if (tab->m_indxs[m] == tab->index[m]) wcsprintf("  (= index[%d])", m);
+@@ -701,7 +758,7 @@ int tabprt(const struct tabprm *tab)
    return 0;
  }
  
@@ -22195,7 +24479,7 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
  
  int tabperr(const struct tabprm *tab, const char *prefix)
  
-@@ -715,7 +712,7 @@ int tabperr(const struct tabprm *tab, co
+@@ -715,52 +772,49 @@ int tabperr(const struct tabprm *tab, co
    return 0;
  }
  
@@ -22204,13 +24488,22 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
  
  int tabset(struct tabprm *tab)
  
-@@ -729,13 +726,13 @@ int tabset(struct tabprm *tab)
+ {
+   static const char *function = "tabset";
+ 
+-  int i, ic, k, *Km, m, M, ne;
+-  double *dcrd, *dmax, *dmin, dPsi, dval, *Psi;
+-  struct wcserr **err;
+-
    if (tab == 0x0) return TABERR_NULL_POINTER;
-   err = &(tab->err);
+-  err = &(tab->err);
++  struct wcserr **err = &(tab->err);
  
 -  /* Check the number of tabular coordinate axes. */
+-  if ((M = tab->M) < 1) {
 +  // Check the number of tabular coordinate axes.
-   if ((M = tab->M) < 1) {
++  int M = tab->M;
++  if (M < 1) {
      return wcserr_set(WCSERR_SET(TABERR_BAD_PARAMS),
        "Invalid tabular parameters: M must be positive, got %d", M);
    }
@@ -22220,7 +24513,14 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
    if (!tab->K) {
      return wcserr_set(WCSERR_SET(TABERR_MEMORY),
        "Null pointers in tabprm struct");
-@@ -749,11 +746,11 @@ int tabset(struct tabprm *tab)
+   }
+ 
+   tab->nc = 1;
+-  for (m = 0; m < M; m++) {
++  for (int m = 0; m < M; m++) {
+     if (tab->K[m] < 1) {
+       return wcserr_set(WCSERR_SET(TABERR_BAD_PARAMS),
+         "Invalid tabular parameters: Each element of K must be positive, "
          "got %d", tab->K[m]);
      }
  
@@ -22234,7 +24534,16 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
    if (!tab->map) {
      return wcserr_set(WCSERR_SET(TABERR_MEMORY),
        "Null pointers in tabprm struct");
-@@ -768,13 +765,13 @@ int tabset(struct tabprm *tab)
+   }
+ 
+-  for (m = 0; m < M; m++) {
+-    i = tab->map[m];
++  for (int m = 0; m < M; m++) {
++    int i = tab->map[m];
+     if (i < 0) {
+       return wcserr_set(WCSERR_SET(TABERR_BAD_PARAMS),
+         "Invalid tabular parameters: Each element of map must be "
+@@ -768,14 +822,14 @@ int tabset(struct tabprm *tab)
      }
    }
  
@@ -22246,11 +24555,13 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
    }
  
 -  /* Take memory if signalled to by wcstab(). */
+-  for (m = 0; m < tab->m_M; m++) {
 +  // Take memory if signalled to by wcstab().
-   for (m = 0; m < tab->m_M; m++) {
++  for (int m = 0; m < tab->m_M; m++) {
      if (tab->m_indxs[m] == (double *)0x1 &&
        (tab->m_indxs[m] = tab->index[m])) {
-@@ -788,15 +785,15 @@ int tabset(struct tabprm *tab)
+       tab->m_flag = TABSET;
+@@ -788,15 +842,15 @@ int tabset(struct tabprm *tab)
    }
  
  
@@ -22269,24 +24580,37 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
      if (!(tab->sense = calloc(M, sizeof(int)))) {
        return wcserr_set(TAB_ERRMSG(TABERR_MEMORY));
      }
-@@ -823,14 +820,14 @@ int tabset(struct tabprm *tab)
+@@ -812,7 +866,7 @@ int tabset(struct tabprm *tab)
+       return wcserr_set(TAB_ERRMSG(TABERR_MEMORY));
+     }
+ 
+-    ne = M * tab->nc * 2 / tab->K[0];
++    int ne = (tab->nc / tab->K[0]) * 2 * M;
+     if (!(tab->extrema = calloc(ne, sizeof(double)))) {
+       free(tab->sense);
+       free(tab->p0);
+@@ -823,32 +877,33 @@ int tabset(struct tabprm *tab)
      tab->set_M = M;
    }
  
 -  /* Check that the index vectors are monotonic. */
+-  Km = tab->K;
+-  for (m = 0; m < M; m++, Km++) {
 +  // Check that the index vectors are monotonic.
-   Km = tab->K;
-   for (m = 0; m < M; m++, Km++) {
++  int *Km = tab->K;
++  for (int m = 0; m < M; m++, Km++) {
      tab->sense[m] = 0;
  
      if (*Km > 1) {
++      double *Psi;
        if ((Psi = tab->index[m]) == 0x0) {
 -        /* Default indexing. */
 +        // Default indexing.
          tab->sense[m] = 1;
  
        } else {
-@@ -838,17 +835,17 @@ int tabset(struct tabprm *tab)
+-        for (k = 0; k < *Km-1; k++) {
++        for (int k = 0; k < *Km-1; k++) {
            switch (tab->sense[m]) {
            case 0:
              if (Psi[k] < Psi[k+1]) {
@@ -22307,7 +24631,7 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
                free(tab->sense);
                free(tab->p0);
                free(tab->delta);
-@@ -861,7 +858,7 @@ int tabset(struct tabprm *tab)
+@@ -861,7 +916,7 @@ int tabset(struct tabprm *tab)
  
            case -1:
              if (Psi[k] < Psi[k+1]) {
@@ -22316,33 +24640,68 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
                free(tab->sense);
                free(tab->p0);
                free(tab->delta);
-@@ -886,14 +883,14 @@ int tabset(struct tabprm *tab)
+@@ -886,22 +941,23 @@ int tabset(struct tabprm *tab)
      }
    }
  
 -  /* Find the extremal values of the coordinate elements in each row. */
+-  dcrd = tab->coord;
+-  dmin = tab->extrema;
+-  dmax = tab->extrema + M;
+-  for (ic = 0; ic < tab->nc; ic += tab->K[0]) {
+-    for (m = 0; m < M; m++, dcrd++) {
 +  // Find the extremal values of the coordinate elements in each row.
-   dcrd = tab->coord;
-   dmin = tab->extrema;
-   dmax = tab->extrema + M;
-   for (ic = 0; ic < tab->nc; ic += tab->K[0]) {
-     for (m = 0; m < M; m++, dcrd++) {
++  double *dcrd = tab->coord;
++  double *dmin = tab->extrema;
++  double *dmax = tab->extrema + M;
++  for (int ic = 0; ic < tab->nc; ic += tab->K[0]) {
++    for (int m = 0; m < M; m++, dcrd++) {
        if (tab->K[0] > 1) {
 -        /* Extrapolate a little before the start of the row. */
+-        Psi = tab->index[0];
 +        // Extrapolate a little before the start of the row.
-         Psi = tab->index[0];
++        double dPsi;
++        double *Psi = tab->index[0];
          if (Psi == 0x0) {
            dPsi = 1.0;
-@@ -919,7 +916,7 @@ int tabset(struct tabprm *tab)
+         } else {
+           dPsi = Psi[1] - Psi[0];
+         }
+ 
+-        dval = *dcrd;
++        double dval = *dcrd;
+         if (dPsi != 0.0) {
+           dval -= 0.5 * (*(dcrd+M) - *dcrd)/dPsi;
+         }
+@@ -913,21 +969,22 @@ int tabset(struct tabprm *tab)
+     }
+ 
+     dcrd -= M;
+-    for (i = 0; i < tab->K[0]; i++) {
+-      for (m = 0; m < M; m++, dcrd++) {
++    for (int i = 0; i < tab->K[0]; i++) {
++      for (int m = 0; m < M; m++, dcrd++) {
+         if (*(dmax+m) < *dcrd) *(dmax+m) = *dcrd;
          if (*(dmin+m) > *dcrd) *(dmin+m) = *dcrd;
  
          if (tab->K[0] > 1 && i == tab->K[0]-1) {
 -          /* Extrapolate a little beyond the end of the row. */
+-          Psi = tab->index[0];
 +          // Extrapolate a little beyond the end of the row.
-           Psi = tab->index[0];
++          double dPsi;
++          double *Psi = tab->index[0];
            if (Psi == 0x0) {
              dPsi = 1.0;
-@@ -947,7 +944,7 @@ int tabset(struct tabprm *tab)
+           } else {
+             dPsi = Psi[i] - Psi[i-1];
+           }
+ 
+-          dval = *dcrd;
++          double dval = *dcrd;
+           if (dPsi != 0.0) {
+             dval += 0.5 * (*dcrd - *(dcrd-M))/dPsi;
+           }
+@@ -947,7 +1004,7 @@ int tabset(struct tabprm *tab)
    return 0;
  }
  
@@ -22351,9 +24710,21 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
  
  int tabx2s(
    struct tabprm *tab,
-@@ -970,12 +967,12 @@ int tabx2s(
+@@ -960,48 +1017,44 @@ int tabx2s(
+ {
+   static const char *function = "tabx2s";
+ 
+-  int i, iv, k, *Km, m, M, n, nv, offset, p1, status;
+-  double *coord, *Psi, psi_m, upsilon, wgt;
+-  register int *statp;
+-  register const double *xp;
+-  register double *wp;
+-  struct wcserr **err;
++  int status;
+ 
    if (tab == 0x0) return TABERR_NULL_POINTER;
-   err = &(tab->err);
+-  err = &(tab->err);
++  struct wcserr **err = &(tab->err);
  
 -  /* Initialize if required. */
 +  // Initialize if required.
@@ -22362,24 +24733,35 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
    }
  
 -  /* This is used a lot. */
+-  M = tab->M;
 +  // This is used a lot.
-   M = tab->M;
++  int M = tab->M;
  
    status = 0;
-@@ -983,25 +980,25 @@ int tabx2s(
-   wp = world;
-   statp = stat;
-   for (n = 0; n < ncoord; n++) {
+-  xp = x;
+-  wp = world;
+-  statp = stat;
+-  for (n = 0; n < ncoord; n++) {
 -    /* Determine the indexes. */
-+    // Determine the indexes.
-     Km = tab->K;
-     for (m = 0; m < M; m++, Km++) {
+-    Km = tab->K;
+-    for (m = 0; m < M; m++, Km++) {
 -      /* N.B. psi_m and Upsilon_m are 1-relative FITS indexes. */
+-      i = tab->map[m];
+-      psi_m = *(xp+i) + tab->crval[m];
++  register const double *xp = x;
++  register double *wp = world;
++  register int *statp = stat;
++  for (int n = 0; n < ncoord; n++) {
++    // Determine the indexes.
++    int *Km = tab->K;
++    for (int m = 0; m < M; m++, Km++) {
 +      // N.B. psi_m and Upsilon_m are 1-relative FITS indexes.
-       i = tab->map[m];
-       psi_m = *(xp+i) + tab->crval[m];
++      int i = tab->map[m];
++      double psi_m = *(xp+i) + tab->crval[m];
  
-       Psi = tab->index[m];
+-      Psi = tab->index[m];
++      double *Psi = tab->index[m];
++      double upsilon;
        if (Psi == 0x0) {
 -        /* Default indexing is simple. */
 +        // Default indexing is simple.
@@ -22398,12 +24780,13 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
            if (Psi[1]-0.5 <= psi_m && psi_m <= Psi[1]+0.5) {
              upsilon = psi_m;
            } else {
-@@ -1011,16 +1008,16 @@ int tabx2s(
+@@ -1011,16 +1064,17 @@ int tabx2s(
            }
  
          } else {
 -          /* Interpolate in the indexing vector. */
 +          // Interpolate in the indexing vector.
++	  int k;
            if (tab->sense[m] == 1) {
 -            /* Monotonic increasing index values. */
 +            // Monotonic increasing index values.
@@ -22419,7 +24802,7 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
                  *statp = 1;
                  status = wcserr_set(TAB_ERRMSG(TABERR_BAD_X));
                  goto next;
-@@ -1028,11 +1025,11 @@ int tabx2s(
+@@ -1028,11 +1082,11 @@ int tabx2s(
  
              } else if (Psi[*Km] < psi_m) {
                if (psi_m <= Psi[*Km] + 0.5*(Psi[*Km]-Psi[*Km-1])) {
@@ -22433,7 +24816,7 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
                  *statp = 1;
                  status = wcserr_set(TAB_ERRMSG(TABERR_BAD_X));
                  goto next;
-@@ -1053,14 +1050,14 @@ int tabx2s(
+@@ -1053,14 +1107,14 @@ int tabx2s(
              }
  
            } else {
@@ -22451,7 +24834,7 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
                  *statp = 1;
                  status = wcserr_set(TAB_ERRMSG(TABERR_BAD_X));
                  goto next;
-@@ -1068,11 +1065,11 @@ int tabx2s(
+@@ -1068,11 +1122,11 @@ int tabx2s(
  
              } else if (psi_m < Psi[*Km]) {
                if (Psi[*Km] - 0.5*(Psi[*Km-1]-Psi[*Km]) <= psi_m) {
@@ -22465,7 +24848,7 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
                  *statp = 1;
                  status = wcserr_set(TAB_ERRMSG(TABERR_BAD_X));
                  goto next;
-@@ -1098,41 +1095,41 @@ int tabx2s(
+@@ -1098,44 +1152,44 @@ int tabx2s(
        }
  
        if (upsilon < 0.5 || upsilon > *Km + 0.5) {
@@ -22478,9 +24861,10 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
  
 -      /* Fiducial array indices and fractional offset.
 -         p1 is 1-relative while tab::p0 is 0-relative. */
+-      p1 = (int)floor(upsilon);
 +      // Fiducial array indices and fractional offset.
 +      // p1 is 1-relative while tab::p0 is 0-relative.
-       p1 = (int)floor(upsilon);
++      int p1 = (int)floor(upsilon);
        tab->p0[m] = p1 - 1;
        tab->delta[m] = upsilon - p1;
  
@@ -22500,32 +24884,49 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
  
 -    /* Now interpolate in the coordinate array; the M-dimensional linear  */
 -    /* interpolation algorithm is described in Sect. 3.4 of WCS Paper IV. */
+-    for (m = 0; m < M; m++) {
+-     i = tab->map[m];
+-     *(wp+i) = 0.0;
 +    // Now interpolate in the coordinate array; the M-dimensional linear
 +    // interpolation algorithm is described in Sect. 3.4 of WCS Paper IV.
-     for (m = 0; m < M; m++) {
-      i = tab->map[m];
-      *(wp+i) = 0.0;
++    for (int m = 0; m < M; m++) {
++      int i = tab->map[m];
++      *(wp+i) = 0.0;
      }
  
 -    /* Loop over the 2^M vertices surrounding P. */
-+    // Loop over the 2^M vertices surrounding P.
-     nv = 1 << M;
-     for (iv = 0; iv < nv; iv++) {
+-    nv = 1 << M;
+-    for (iv = 0; iv < nv; iv++) {
 -      /* Locate vertex in the coordinate array and compute its weight. */
+-      offset = 0;
+-      wgt = 1.0;
+-      for (m = M-1; m >= 0; m--) {
++    // Loop over the 2^M vertices surrounding P.
++    int nv = 1 << M;
++    for (int iv = 0; iv < nv; iv++) {
 +      // Locate vertex in the coordinate array and compute its weight.
-       offset = 0;
-       wgt = 1.0;
-       for (m = M-1; m >= 0; m--) {
-@@ -1148,7 +1145,7 @@ int tabx2s(
++      int offset = 0;
++      double wgt = 1.0;
++      for (int m = M-1; m >= 0; m--) {
+         offset *= tab->K[m];
+         offset += tab->p0[m];
+         if (iv & (1 << m)) {
+@@ -1148,10 +1202,10 @@ int tabx2s(
  
        if (wgt == 0.0) continue;
  
 -      /* Add the contribution from this vertex to each element. */
+-      coord = tab->coord + offset*M;
+-      for (m = 0; m < M; m++) {
+-        i = tab->map[m];
 +      // Add the contribution from this vertex to each element.
-       coord = tab->coord + offset*M;
-       for (m = 0; m < M; m++) {
-         i = tab->map[m];
-@@ -1169,9 +1166,9 @@ next:
++      double *coord = tab->coord + offset*M;
++      for (int m = 0; m < M; m++) {
++        int i = tab->map[m];
+         *(wp+i) += *(coord++) * wgt;
+       }
+ 
+@@ -1169,9 +1223,9 @@ next:
    return status;
  }
  
@@ -22537,9 +24938,21 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
  static int tabedge(struct tabprm *);
  static int tabrow(struct tabprm *, const double *);
  static int tabvox(struct tabprm *, const double *, int, double **,
-@@ -1198,12 +1195,12 @@ int tabs2x(
+@@ -1188,26 +1242,21 @@ int tabs2x(
+ {
+   static const char *function = "tabs2x";
+ 
+-  int edge, i, ic, iv, k, *Km, M, m, n, nv, offset, status;
+-  double *dcrd, delta, *Psi, psi_m, **tabcoord, upsilon;
+-  register int *statp;
+-  register const double *wp;
+-  register double *xp;
+-  struct wcserr **err;
++  int status;
+ 
    if (tab == 0x0) return TABERR_NULL_POINTER;
-   err = &(tab->err);
+-  err = &(tab->err);
++  struct wcserr **err = &(tab->err);
  
 -  /* Initialize if required. */
 +  // Initialize if required.
@@ -22548,21 +24961,39 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
    }
  
 -  /* This is used a lot. */
+-  M = tab->M;
 +  // This is used a lot.
-   M = tab->M;
++  int M = tab->M;
  
-   tabcoord = 0x0;
-@@ -1219,7 +1216,7 @@ int tabs2x(
-   xp = x;
-   statp = stat;
-   for (n = 0; n < ncoord; n++) {
+-  tabcoord = 0x0;
+-  nv = 0;
++  double **tabcoord = 0x0;
++  int nv = 0;
+   if (M > 1) {
+     nv = 1 << M;
+     tabcoord = calloc(nv, sizeof(double *));
+@@ -1215,59 +1264,61 @@ int tabs2x(
+ 
+ 
+   status = 0;
+-  wp = world;
+-  xp = x;
+-  statp = stat;
+-  for (n = 0; n < ncoord; n++) {
 -    /* Locate this coordinate in the coordinate array. */
+-    edge = 0;
+-    for (m = 0; m < M; m++) {
++  register const double *wp = world;
++  register double *xp = x;
++  register int *statp = stat;
++  for (int n = 0; n < ncoord; n++) {
 +    // Locate this coordinate in the coordinate array.
-     edge = 0;
-     for (m = 0; m < M; m++) {
++    int edge = 0;
++    for (int m = 0; m < M; m++) {
        tab->p0[m] = 0;
-@@ -1227,23 +1224,23 @@ int tabs2x(
+     }
  
++    int ic;
      for (ic = 0; ic < tab->nc; ic++) {
        if (tab->p0[0] == 0) {
 -        /* New row, could it contain a solution? */
@@ -22585,11 +25016,27 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
  
        if (M == 1) {
 -        /* Deal with the one-dimensional case separately for efficiency. */
+-        if (*wp == tab->coord[0]) {
 +        // Deal with the one-dimensional case separately for efficiency.
-         if (*wp == tab->coord[0]) {
++        double w = wp[tab->map[0]];
++        if (w == tab->coord[0]) {
            tab->p0[0] = 0;
            tab->delta[0] = 0.0;
-@@ -1262,9 +1259,9 @@ int tabs2x(
+           break;
+ 
+         } else if (ic < tab->nc - 1) {
+-          if (((tab->coord[ic] <= *wp && *wp <= tab->coord[ic+1]) ||
+-               (tab->coord[ic] >= *wp && *wp >= tab->coord[ic+1])) &&
++          if (((tab->coord[ic] <= w && w <= tab->coord[ic+1]) ||
++               (tab->coord[ic] >= w && w >= tab->coord[ic+1])) &&
+                (tab->index[0] == 0x0 ||
+                 tab->index[0][ic] != tab->index[0][ic+1])) {
+             tab->p0[0] = ic;
+-            tab->delta[0] = (*wp - tab->coord[ic]) /
++            tab->delta[0] = (w - tab->coord[ic]) /
+                             (tab->coord[ic+1] - tab->coord[ic]);
+             break;
+           }
          }
  
        } else {
@@ -22597,11 +25044,17 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
 +        // Multi-dimensional tables are harder.
          if (!edge) {
 -          /* Addresses of the coordinates for each corner of the "voxel". */
+-          for (iv = 0; iv < nv; iv++) {
+-            offset = 0;
+-            for (m = M-1; m >= 0; m--) {
 +          // Addresses of the coordinates for each corner of the "voxel".
-           for (iv = 0; iv < nv; iv++) {
-             offset = 0;
-             for (m = M-1; m >= 0; m--) {
-@@ -1276,12 +1273,12 @@ int tabs2x(
++          for (int iv = 0; iv < nv; iv++) {
++            int offset = 0;
++            for (int m = M-1; m >= 0; m--) {
+               offset *= tab->K[m];
+               offset += tab->p0[m];
+               if ((iv & (1 << m)) && (tab->K[m] > 1)) offset++;
+@@ -1276,12 +1327,12 @@ int tabs2x(
            }
  
            if (tabvox(tab, wp, 0, tabcoord, 0x0) == 0) {
@@ -22616,7 +25069,7 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
          tab->p0[0]++;
          edge = tabedge(tab);
        }
-@@ -1289,9 +1286,9 @@ int tabs2x(
+@@ -1289,15 +1340,16 @@ int tabs2x(
  
  
      if (ic == tab->nc) {
@@ -22624,11 +25077,22 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
 +      // Coordinate not found; allow minor extrapolation.
        if (M == 1) {
 -        /* Should there be a solution? */
+-        if (tab->extrema[0] <= *wp && *wp <= tab->extrema[1]) {
+-          dcrd = tab->coord;
+-          for (i = 0; i < 2; i++) {
 +        // Should there be a solution?
-         if (tab->extrema[0] <= *wp && *wp <= tab->extrema[1]) {
-           dcrd = tab->coord;
-           for (i = 0; i < 2; i++) {
-@@ -1317,43 +1314,43 @@ int tabs2x(
++        double w = wp[tab->map[0]];
++        if (tab->extrema[0] <= w && w <= tab->extrema[1]) {
++          double *dcrd = tab->coord;
++          for (int i = 0; i < 2; i++) {
+             if (i) dcrd += tab->K[0] - 2;
+ 
+-            delta = (*wp - *dcrd) / (*(dcrd+1) - *dcrd);
++            double delta = (w - *dcrd) / (*(dcrd+1) - *dcrd);
+ 
+             if (i == 0) {
+               if (-0.5 <= delta && delta <= 0.0) {
+@@ -1317,46 +1369,47 @@ int tabs2x(
          }
  
        } else {
@@ -22648,12 +25112,15 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
  
      } else {
 -      /* Determine the intermediate world coordinates. */
-+      // Determine the intermediate world coordinates.
-       Km = tab->K;
-       for (m = 0; m < M; m++, Km++) {
+-      Km = tab->K;
+-      for (m = 0; m < M; m++, Km++) {
 -        /* N.B. Upsilon_m and psi_m are 1-relative FITS indexes. */
+-        upsilon = (tab->p0[m] + 1) + tab->delta[m];
++      // Determine the intermediate world coordinates.
++      int *Km = tab->K;
++      for (int m = 0; m < M; m++, Km++) {
 +        // N.B. Upsilon_m and psi_m are 1-relative FITS indexes.
-         upsilon = (tab->p0[m] + 1) + tab->delta[m];
++        double upsilon = (tab->p0[m] + 1) + tab->delta[m];
  
          if (upsilon < 0.5 || upsilon > *Km + 0.5) {
 -          /* Index out of range. */
@@ -22663,8 +25130,10 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
  
          } else {
 -          /* Do inverse lookup of the index vector. */
+-          Psi = tab->index[m];
 +          // Do inverse lookup of the index vector.
-           Psi = tab->index[m];
++          double *Psi = tab->index[m];
++          double psi_m;
            if (Psi == 0x0) {
 -            /* Default indexing. */
 +            // Default indexing.
@@ -22682,10 +25151,31 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
 +              // Degenerate index vector.
                psi_m = Psi[1];
              } else {
-               k = (int)(upsilon);
-@@ -1396,14 +1393,14 @@ int tabedge(struct tabprm* tab)
-   edge = 0;
-   for (m = 0; m < tab->M; m++) {
+-              k = (int)(upsilon);
++              int k = (int)(upsilon);
+               psi_m = Psi[k];
+               if (k < *Km) {
+                 psi_m += (upsilon - k) * (Psi[k+1] - Psi[k]);
+@@ -1364,8 +1417,7 @@ int tabs2x(
+             }
+           }
+ 
+-          i = tab->map[m];
+-          xp[i] = psi_m - tab->crval[m];
++          xp[tab->map[m]] = psi_m - tab->crval[m];
+         }
+       }
+       *statp = 0;
+@@ -1391,19 +1443,18 @@ int tabs2x(
+ int tabedge(struct tabprm* tab)
+ 
+ {
+-  int edge, m;
++  int edge = 0;
+ 
+-  edge = 0;
+-  for (m = 0; m < tab->M; m++) {
++  for (int m = 0; m < tab->M; m++) {
      if (tab->p0[m] == tab->K[m]) {
 -      /* p0 has been incremented beyond the end of an index vector, point it
 -         to the next one. */
@@ -22701,26 +25191,42 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
        edge = 1;
      }
    }
-@@ -1450,48 +1447,48 @@ int tabrow(struct tabprm* tab, const dou
+@@ -1443,55 +1494,52 @@ int tabedge(struct tabprm* tab)
+ int tabrow(struct tabprm* tab, const double *wp)
  
-   M = tab->M;
+ {
+-  int M, m, offset;
+-  unsigned int eq, gt, iv, lt, nv;
+   const double tol = 1e-10;
+-  double *cp, w;
+ 
+-  M = tab->M;
++  int M = tab->M;
  
 -  /* The number of corners in a "voxel".  We need examine only half this
 -     number of rows.  The extra factor of two will be used to select between
 -     the minimal and maximal values in each row. */
+-  nv = 1 << M;
+-
+-  eq = 0;
+-  lt = 0;
+-  gt = 0;
+-  for (iv = 0; iv < nv; iv++) {
+-    /* Find the index into tabprm::extrema for this row. */
+-    offset = 0;
+-    for (m = M-1; m > 0; m--) {
 +  // The number of corners in a "voxel".  We need examine only half this
 +  // number of rows.  The extra factor of two will be used to select between
 +  // the minimal and maximal values in each row.
-   nv = 1 << M;
- 
-   eq = 0;
-   lt = 0;
-   gt = 0;
-   for (iv = 0; iv < nv; iv++) {
--    /* Find the index into tabprm::extrema for this row. */
++  unsigned int nv = 1 << M;
++
++  unsigned int eq = 0;
++  unsigned int lt = 0;
++  unsigned int gt = 0;
++  for (unsigned int iv = 0; iv < nv; iv++) {
 +    // Find the index into tabprm::extrema for this row.
-     offset = 0;
-     for (m = M-1; m > 0; m--) {
++    int offset = 0;
++    for (int m = M-1; m > 0; m--) {
        offset *= tab->K[m];
        offset += tab->p0[m];
  
@@ -22744,28 +25250,31 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
      offset *= M;
  
 -    /* Address of the extremal elements (min or max) for this row. */
+-    cp = tab->extrema + offset;
 +    // Address of the extremal elements (min or max) for this row.
-     cp = tab->extrema + offset;
++    double *cp = tab->extrema + offset;
  
 -    /* For each coordinate element, we only need to find one row where its
 -       minimum value is less than that of wp, and one row where the maximum
 -       value is greater.  That doesn't mean that there is a solution, only
 -       that there might be. */
+-    for (m = 0; m < M; m++, cp++) {
+-      /* Apply the axis mapping. */
+-      w = wp[tab->map[m]];
 +    // For each coordinate element, we only need to find one row where its
 +    // minimum value is less than that of wp, and one row where the maximum
 +    // value is greater.  That doesn't mean that there is a solution, only
 +    // that there might be.
-     for (m = 0; m < M; m++, cp++) {
--      /* Apply the axis mapping. */
++    for (int m = 0; m < M; m++, cp++) {
 +      // Apply the axis mapping.
-       w = wp[tab->map[m]];
++      double w = wp[tab->map[m]];
  
 -      /* Finally the test itself; set bits in the bitmask. */
 +      // Finally the test itself; set bits in the bitmask.
        if (fabs(*cp - w) < tol) {
          eq |= (1 << m);
        } else if (*cp < w) {
-@@ -1501,14 +1498,14 @@ int tabrow(struct tabprm* tab, const dou
+@@ -1501,14 +1549,14 @@ int tabrow(struct tabprm* tab, const dou
        }
      }
  
@@ -22783,77 +25292,106 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
    return 1;
  }
  
-@@ -1547,7 +1544,7 @@ int tabvox(
+@@ -1540,30 +1588,28 @@ int tabvox(
+   unsigned int *vox)
  
-   M = tab->M;
+ {
+-  int i, M, m;
+-  unsigned int eq, et, gt, iv, jv, lt, nv, vox2[32];
+   const double tol = 1e-10;
+-  double coord[32], *cp, dv, w, wgt;
+ 
+-  M = tab->M;
++  int M = tab->M;
  
 -  /* The number of corners in a voxel. */
+-  nv = 1 << M;
 +  // The number of corners in a voxel.
-   nv = 1 << M;
++  unsigned int nv = 1 << M;
  
-   dv = 1.0;
-@@ -1555,14 +1552,14 @@ int tabvox(
+-  dv = 1.0;
+-  for (i = 0; i < level; i++) {
++  double dv = 1.0;
++  for (int i = 0; i < level; i++) {
      dv /= 2.0;
    }
  
 -  /* Could the coordinate lie within this voxel (level == 0) or sub-voxel
 -     (level > 0)?  We use the fact that with linear interpolation the
 -     coordinate elements are extremal in a corner and test each one. */
+-  lt = 0;
+-  gt = 0;
+-  eq = 0;
+-  for (iv = 0; iv < nv; iv++) {
+-    /* Select a corner of the sub-voxel. */
+-    for (m = 0; m < M; m++) {
 +  // Could the coordinate lie within this voxel (level == 0) or sub-voxel
 +  // (level > 0)?  We use the fact that with linear interpolation the
 +  // coordinate elements are extremal in a corner and test each one.
-   lt = 0;
-   gt = 0;
-   eq = 0;
-   for (iv = 0; iv < nv; iv++) {
--    /* Select a corner of the sub-voxel. */
++  unsigned int lt = 0;
++  unsigned int gt = 0;
++  unsigned int eq = 0;
++  for (unsigned int iv = 0; iv < nv; iv++) {
 +    // Select a corner of the sub-voxel.
-     for (m = 0; m < M; m++) {
++    double coord[32];
++    for (int m = 0; m < M; m++) {
        coord[m] = 0.0;
        tab->delta[m] = level ? dv*vox[m] : 0.0;
-@@ -1572,11 +1569,11 @@ int tabvox(
+ 
+@@ -1572,13 +1618,13 @@ int tabvox(
        }
      }
  
 -    /* Compute the coordinates of this corner of the sub-voxel by linear
 -       interpolation using the weighting algorithm described in Sect. 3.4 of
 -       WCS Paper IV. */
+-    for (jv = 0; jv < nv; jv++) {
+-      /* Find the weight for this corner of the parent voxel. */
+-      wgt = 1.0;
+-      for (m = 0; m < M; m++) {
 +    // Compute the coordinates of this corner of the sub-voxel by linear
 +    // interpolation using the weighting algorithm described in Sect. 3.4 of
 +    // WCS Paper IV.
-     for (jv = 0; jv < nv; jv++) {
--      /* Find the weight for this corner of the parent voxel. */
++    for (unsigned int jv = 0; jv < nv; jv++) {
 +      // Find the weight for this corner of the parent voxel.
-       wgt = 1.0;
-       for (m = 0; m < M; m++) {
++      double wgt = 1.0;
++      for (int m = 0; m < M; m++) {
          if (jv & (1 << m)) {
-@@ -1588,7 +1585,7 @@ int tabvox(
+           wgt *= tab->delta[m];
+         } else {
+@@ -1588,22 +1634,22 @@ int tabvox(
  
        if (wgt == 0.0) continue;
  
 -      /* Add its contribution to each coordinate element. */
+-      cp = tabcoord[jv];
+-      for (m = 0; m < M; m++) {
 +      // Add its contribution to each coordinate element.
-       cp = tabcoord[jv];
-       for (m = 0; m < M; m++) {
++      double *cp = tabcoord[jv];
++      for (int m = 0; m < M; m++) {
          coord[m] += *(cp++) * wgt;
-@@ -1597,13 +1594,13 @@ int tabvox(
+       }
+ 
        if (wgt == 1.0) break;
      }
  
 -    /* Coordinate elements are minimal or maximal in a corner. */
-+    // Coordinate elements are minimal or maximal in a corner.
-     et = 0;
-     for (m = 0; m < M; m++) {
+-    et = 0;
+-    for (m = 0; m < M; m++) {
 -      /* Apply the axis mapping. */
+-      w = wp[tab->map[m]];
++    // Coordinate elements are minimal or maximal in a corner.
++    unsigned int et = 0;
++    for (int m = 0; m < M; m++) {
 +      // Apply the axis mapping.
-       w = wp[tab->map[m]];
++      double w = wp[tab->map[m]];
  
 -      /* Finally the test itself; set bits in the bitmask. */
 +      // Finally the test itself; set bits in the bitmask.
        if (fabs(coord[m] - w) < tol) {
          et |= (1 << m);
        } else if (coord[m] < w) {
-@@ -1614,20 +1611,20 @@ int tabvox(
+@@ -1614,45 +1660,46 @@ int tabvox(
      }
  
      if (et == nv-1) {
@@ -22877,21 +25415,26 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
 -      /* We have a solution, squeeze out the last bit of juice. */
 +      // We have a solution, squeeze out the last bit of juice.
        dv /= 2.0;
-       for (m = 0; m < M; m++) {
+-      for (m = 0; m < M; m++) {
++      for (int m = 0; m < M; m++) {
          tab->delta[m] = dv * (2.0*vox[m] + 1.0);
-@@ -1636,9 +1633,9 @@ int tabvox(
+       }
+ 
        return 0;
      }
  
 -    /* Subdivide the sub-voxel and try again for each subdivision. */
-+    // Subdivide the sub-voxel and try again for each subdivision.
-     for (iv = 0; iv < nv; iv++) {
+-    for (iv = 0; iv < nv; iv++) {
 -      /* Select the subdivision. */
+-      for (m = 0; m < M; m++) {
++    // Subdivide the sub-voxel and try again for each subdivision.
++    for (unsigned int iv = 0; iv < nv; iv++) {
 +      // Select the subdivision.
-       for (m = 0; m < M; m++) {
++      unsigned int vox2[32];
++      for (int m = 0; m < M; m++) {
          vox2[m] = level ? 2*vox[m] : 0;
          if (iv & (1 << m)) {
-@@ -1646,13 +1643,13 @@ int tabvox(
+           vox2[m]++;
          }
        }
  
@@ -22907,16 +25450,16 @@ Index: astropy-4.2/cextern/wcslib/C/tab.c
 +  // No solution in this sub-voxel.
    return 1;
  }
-Index: astropy-4.2/cextern/wcslib/C/tab.h
+Index: astropy-4.2.1/cextern/wcslib/C/tab.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/tab.h
-+++ astropy-4.2/cextern/wcslib/C/tab.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/tab.h
++++ astropy-4.2.1/cextern/wcslib/C/tab.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -22930,15 +25473,61 @@ Index: astropy-4.2/cextern/wcslib/C/tab.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: tab.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: tab.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: tab.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
-@@ -533,65 +530,65 @@ extern "C" {
+@@ -52,7 +49,8 @@
+ * encapsulation.
+ *
+ * tabini(), tabmem(), tabcpy(), and tabfree() are provided to manage the
+-* tabprm struct, and another, tabprt(), to print its contents.
++* tabprm struct, tabsize() computes its total size including allocated memory,
++* and tabprt() prints its contents.
+ *
+ * tabperr() prints the error message(s) (if any) stored in a tabprm struct.
+ *
+@@ -235,6 +233,35 @@
+ *                         1: Null tabprm pointer passed.
+ *
+ *
++* tabsize() - Compute the size of a tabprm struct
++* -----------------------------------------------
++* tabsize() computes the full size of a tabprm struct, including allocated
++* memory.
++*
++* Given:
++*   tab       const struct tabprm*
++*                       Tabular transformation parameters.
++*
++*                       If NULL, the base size of the struct and the allocated
++*                       size are both set to zero.
++*
++* Returned:
++*   sizes     int[2]    The first element is the base size of the struct as
++*                       returned by sizeof(struct tabprm).  The second element
++*                       is the total allocated size, in bytes, assuming that
++*                       the allocation was done by tabini().  This figure
++*                       includes memory allocated for the constituent struct,
++*                       tabprm::err.
++*
++*                       It is not an error for the struct not to have been set
++*                       up via tabset(), which normally results in additional
++*                       memory allocation. 
++*
++* Function return value:
++*             int       Status return value:
++*                         0: Success.
++*
++*
+ * tabprt() - Print routine for the tabprm struct
+ * ----------------------------------------------
+ * tabprt() prints the contents of a tabprm struct using wcsprintf().  Mainly
+@@ -533,65 +560,65 @@ extern "C" {
  extern const char *tab_errmsg[];
  
  enum tab_errmsg_enum {
@@ -23051,7 +25640,16 @@ Index: astropy-4.2/cextern/wcslib/C/tab.h
  #define TABLEN (sizeof(struct tabprm)/sizeof(int))
  
  
-@@ -619,7 +616,7 @@ int tabs2x(struct tabprm *tab, int ncoor
+@@ -606,6 +633,8 @@ int tabcmp(int cmp, double tol, const st
+ 
+ int tabfree(struct tabprm *tab);
+ 
++int tabsize(const struct tabprm *tab, int size[2]);
++
+ int tabprt(const struct tabprm *tab);
+ 
+ int tabperr(const struct tabprm *tab, const char *prefix);
+@@ -619,7 +648,7 @@ int tabs2x(struct tabprm *tab, int ncoor
             double x[], int stat[]);
  
  
@@ -23060,22 +25658,22 @@ Index: astropy-4.2/cextern/wcslib/C/tab.h
  #define tabini_errmsg tab_errmsg
  #define tabcpy_errmsg tab_errmsg
  #define tabfree_errmsg tab_errmsg
-@@ -632,4 +629,4 @@ int tabs2x(struct tabprm *tab, int ncoor
+@@ -632,4 +661,4 @@ int tabs2x(struct tabprm *tab, int ncoor
  }
  #endif
  
 -#endif /* WCSLIB_TAB */
 +#endif // WCSLIB_TAB
-Index: astropy-4.2/cextern/wcslib/C/wcs.c
+Index: astropy-4.2.1/cextern/wcslib/C/wcs.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcs.c
-+++ astropy-4.2/cextern/wcslib/C/wcs.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcs.c
++++ astropy-4.2.1/cextern/wcslib/C/wcs.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -23089,7 +25687,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcs.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcs.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcs.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <math.h>
@@ -23107,9 +25705,13 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  const char *wcs_errmsg[] = {
    "Success",
    "Null wcsprm pointer passed",
-@@ -70,70 +67,70 @@ const char *wcs_errmsg[] = {
+@@ -68,72 +65,73 @@ const char *wcs_errmsg[] = {
+   "Invalid world coordinate",
+   "No solution found in the specified interval",
    "Invalid subimage specification",
-   "Non-separable subimage coordinate system"};
+-  "Non-separable subimage coordinate system"};
++  "Non-separable subimage coordinate system",
++  "wcsprm struct is unset, use wcsset()"};
  
 -/* Map error returns for lower-level routines. */
 +// Map error returns for lower-level routines.
@@ -23214,7 +25816,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
  int wcsini(int alloc, int naxis, struct wcsprm *wcs)
  
-@@ -141,7 +138,7 @@ int wcsini(int alloc, int naxis, struct
+@@ -141,7 +139,7 @@ int wcsini(int alloc, int naxis, struct
    return wcsinit(alloc, naxis, wcs, -1, -1, -1);
  }
  
@@ -23223,7 +25825,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
  int wcsinit(
    int alloc,
-@@ -158,23 +155,23 @@ int wcsinit(
+@@ -158,23 +156,23 @@ int wcsinit(
    double *cd;
    struct wcserr **err;
  
@@ -23252,7 +25854,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if (wcs->flag == -1) {
      wcs->lin.err = 0x0;
      wcs->cel.err = 0x0;
-@@ -185,7 +182,7 @@ int wcsinit(
+@@ -185,7 +183,7 @@ int wcsinit(
    wcserr_clear(&(wcs->spc.err));
  
  
@@ -23261,7 +25863,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if (wcs->flag == -1 || wcs->m_flag != WCSSET) {
      if (wcs->flag == -1) {
        wcs->tab   = 0x0;
-@@ -193,7 +190,7 @@ int wcsinit(
+@@ -193,7 +191,7 @@ int wcsinit(
        wcs->lin.flag = -1;
      }
  
@@ -23270,7 +25872,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
      wcs->m_flag  = 0;
      wcs->m_naxis = 0;
      wcs->m_crpix = 0x0;
-@@ -223,7 +220,7 @@ int wcsinit(
+@@ -223,7 +221,7 @@ int wcsinit(
    }
  
  
@@ -23279,7 +25881,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if (alloc ||
       wcs->crpix == 0x0 ||
       wcs->pc    == 0x0 ||
-@@ -242,18 +239,18 @@ int wcsinit(
+@@ -242,18 +240,18 @@ int wcsinit(
       wcs->czphs == 0x0 ||
       wcs->cperi == 0x0) {
  
@@ -23301,7 +25903,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->crpix = wcs->m_crpix;
  
        } else {
-@@ -269,7 +266,7 @@ int wcsinit(
+@@ -269,7 +267,7 @@ int wcsinit(
  
      if (alloc || wcs->pc == 0x0) {
        if (wcs->m_pc) {
@@ -23310,7 +25912,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->pc = wcs->m_pc;
  
        } else {
-@@ -286,7 +283,7 @@ int wcsinit(
+@@ -286,7 +284,7 @@ int wcsinit(
  
      if (alloc || wcs->cdelt == 0x0) {
        if (wcs->m_cdelt) {
@@ -23319,7 +25921,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->cdelt = wcs->m_cdelt;
  
        } else {
-@@ -303,7 +300,7 @@ int wcsinit(
+@@ -303,7 +301,7 @@ int wcsinit(
  
      if (alloc || wcs->crval == 0x0) {
        if (wcs->m_crval) {
@@ -23328,7 +25930,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->crval = wcs->m_crval;
  
        } else {
-@@ -320,7 +317,7 @@ int wcsinit(
+@@ -320,7 +318,7 @@ int wcsinit(
  
      if (alloc || wcs->cunit == 0x0) {
        if (wcs->m_cunit) {
@@ -23337,7 +25939,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->cunit = wcs->m_cunit;
  
        } else {
-@@ -337,7 +334,7 @@ int wcsinit(
+@@ -337,7 +335,7 @@ int wcsinit(
  
      if (alloc || wcs->ctype == 0x0) {
        if (wcs->m_ctype) {
@@ -23346,7 +25948,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->ctype = wcs->m_ctype;
  
        } else {
-@@ -354,7 +351,7 @@ int wcsinit(
+@@ -354,7 +352,7 @@ int wcsinit(
  
      if (alloc || wcs->pv == 0x0) {
        if (wcs->m_pv) {
@@ -23355,7 +25957,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->pv = wcs->m_pv;
  
        } else {
-@@ -377,7 +374,7 @@ int wcsinit(
+@@ -377,7 +375,7 @@ int wcsinit(
  
      if (alloc || wcs->ps == 0x0) {
        if (wcs->m_ps) {
@@ -23364,7 +25966,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->ps = wcs->m_ps;
  
        } else {
-@@ -400,7 +397,7 @@ int wcsinit(
+@@ -400,7 +398,7 @@ int wcsinit(
  
      if (alloc || wcs->cd == 0x0) {
        if (wcs->m_cd) {
@@ -23373,7 +25975,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->cd = wcs->m_cd;
  
        } else {
-@@ -417,7 +414,7 @@ int wcsinit(
+@@ -417,7 +415,7 @@ int wcsinit(
  
      if (alloc || wcs->crota == 0x0) {
        if (wcs->m_crota) {
@@ -23382,7 +25984,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->crota = wcs->m_crota;
  
        } else {
-@@ -434,7 +431,7 @@ int wcsinit(
+@@ -434,7 +432,7 @@ int wcsinit(
  
      if (alloc || wcs->colax == 0x0) {
        if (wcs->m_colax) {
@@ -23391,7 +25993,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->colax = wcs->m_colax;
  
        } else {
-@@ -451,7 +448,7 @@ int wcsinit(
+@@ -451,7 +449,7 @@ int wcsinit(
  
      if (alloc || wcs->cname == 0x0) {
        if (wcs->m_cname) {
@@ -23400,7 +26002,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->cname = wcs->m_cname;
  
        } else {
-@@ -468,7 +465,7 @@ int wcsinit(
+@@ -468,7 +466,7 @@ int wcsinit(
  
      if (alloc || wcs->crder == 0x0) {
        if (wcs->m_crder) {
@@ -23409,7 +26011,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->crder = wcs->m_crder;
  
        } else {
-@@ -485,7 +482,7 @@ int wcsinit(
+@@ -485,7 +483,7 @@ int wcsinit(
  
      if (alloc || wcs->csyer == 0x0) {
        if (wcs->m_csyer) {
@@ -23418,7 +26020,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->csyer = wcs->m_csyer;
  
        } else {
-@@ -502,7 +499,7 @@ int wcsinit(
+@@ -502,7 +500,7 @@ int wcsinit(
  
      if (alloc || wcs->czphs == 0x0) {
        if (wcs->m_czphs) {
@@ -23427,7 +26029,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->czphs = wcs->m_czphs;
  
        } else {
-@@ -519,7 +516,7 @@ int wcsinit(
+@@ -519,7 +517,7 @@ int wcsinit(
  
      if (alloc || wcs->cperi == 0x0) {
        if (wcs->m_cperi) {
@@ -23436,7 +26038,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->cperi = wcs->m_cperi;
  
        } else {
-@@ -540,7 +537,7 @@ int wcsinit(
+@@ -540,7 +538,7 @@ int wcsinit(
    wcs->naxis = naxis;
  
  
@@ -23445,7 +26047,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    wcs->lin.crpix  = wcs->crpix;
    wcs->lin.pc     = wcs->pc;
    wcs->lin.cdelt  = wcs->cdelt;
-@@ -549,28 +546,28 @@ int wcsinit(
+@@ -549,28 +547,28 @@ int wcsinit(
    }
  
  
@@ -23479,7 +26081,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    wcs->npv = 0;
    for (k = 0; k < wcs->npvmax; k++) {
      wcs->pv[k].i = 0;
-@@ -585,7 +582,7 @@ int wcsinit(
+@@ -585,7 +583,7 @@ int wcsinit(
      memset(wcs->ps[k].value, 0, 72);
    }
  
@@ -23488,7 +26090,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    cd = wcs->cd;
    for (i = 0; i < naxis; i++) {
      for (j = 0; j < naxis; j++) {
-@@ -598,7 +595,7 @@ int wcsinit(
+@@ -598,7 +596,7 @@ int wcsinit(
    wcs->altlin = 0;
    wcs->velref = 0;
  
@@ -23497,7 +26099,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    memset(wcs->alt, 0, 4);
    wcs->alt[0] = ' ';
    wcs->colnum = 0;
-@@ -661,16 +658,16 @@ int wcsinit(
+@@ -661,16 +659,16 @@ int wcsinit(
    memset(wcs->ssyssrc,  0, 72);
    wcs->velangl    = UNDEFINED;
  
@@ -23517,8 +26119,12 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    strcpy(wcs->lngtyp, "    ");
    strcpy(wcs->lattyp, "    ");
    wcs->lng  = -1;
-@@ -684,7 +681,7 @@ int wcsinit(
-   return 0;
+@@ -681,10 +679,10 @@ int wcsinit(
+   celini(&(wcs->cel));
+   spcini(&(wcs->spc));
+ 
+-  return 0;
++  return WCSERR_SUCCESS;
  }
  
 -/*--------------------------------------------------------------------------*/
@@ -23526,7 +26132,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
  int wcsauxi(
    int alloc,
-@@ -696,14 +693,14 @@ int wcsauxi(
+@@ -696,14 +694,14 @@ int wcsauxi(
    struct auxprm *aux;
    struct wcserr **err;
  
@@ -23544,8 +26150,12 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        wcs->aux = wcs->m_aux;
  
      } else {
-@@ -725,7 +722,7 @@ int wcsauxi(
-   return 0;
+@@ -722,10 +720,10 @@ int wcsauxi(
+   aux->hgln_obs = UNDEFINED;
+   aux->hglt_obs = UNDEFINED;
+ 
+-  return 0;
++  return WCSERR_SUCCESS;
  }
  
 -/*--------------------------------------------------------------------------*/
@@ -23553,7 +26163,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
  int wcssub(
    int alloc,
-@@ -753,7 +750,7 @@ int wcssub(
+@@ -753,7 +751,7 @@ int wcssub(
    if (wcsdst == 0x0) return WCSERR_NULL_POINTER;
    err = &(wcsdst->err);
  
@@ -23562,7 +26172,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if ((naxis = wcssrc->naxis) <= 0) {
      return wcserr_set(WCSERR_SET(WCSERR_MEMORY),
        "naxis must be positive (got %d)", naxis);
-@@ -766,14 +763,14 @@ int wcssub(
+@@ -766,14 +764,14 @@ int wcssub(
      *nsub = naxis;
    }
  
@@ -23579,7 +26189,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
      if ((axes = calloc(naxis, sizeof(int))) == 0x0) {
        free(itmp);
        return wcserr_set(WCS_ERRMSG(WCSERR_MEMORY));
-@@ -784,7 +781,7 @@ int wcssub(
+@@ -784,7 +782,7 @@ int wcssub(
      }
    }
  
@@ -23588,7 +26198,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    wcsdst->m_aux = 0x0;
    wcsdst->m_tab = 0x0;
  
-@@ -794,7 +791,7 @@ int wcssub(
+@@ -794,7 +792,7 @@ int wcssub(
      axis = axes[j];
  
      if (abs(axis) > 0x1000) {
@@ -23597,7 +26207,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        k = abs(axis) & 0xFF;
  
        longitude = k & WCSSUB_LONGITUDE;
-@@ -815,7 +812,7 @@ int wcssub(
+@@ -815,7 +813,7 @@ int wcssub(
          strncpy (ctypei, (char *)(wcssrc->ctype + i), 8);
          ctypei[8] = '\0';
  
@@ -23606,7 +26216,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          c = ctypei + 8;
          while (c-- > ctypei) {
            if (*c == ' ') *c = '\0';
-@@ -874,7 +871,7 @@ int wcssub(
+@@ -874,7 +872,7 @@ int wcssub(
            continue;
          }
  
@@ -23615,7 +26225,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          for (k = 0; k < msub; k++) {
            if (itmp[k] == i+1) {
              break;
-@@ -884,7 +881,7 @@ int wcssub(
+@@ -884,7 +882,7 @@ int wcssub(
        }
  
      } else if (0 < axis && axis <= naxis) {
@@ -23624,7 +26234,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        for (k = 0; k < msub; k++) {
          if (itmp[k] == axis) {
            break;
-@@ -893,7 +890,7 @@ int wcssub(
+@@ -893,7 +891,7 @@ int wcssub(
        if (k == msub) itmp[msub++] = axis;
  
      } else if (axis == 0) {
@@ -23633,7 +26243,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        itmp[msub++] = 0;
  
      } else {
-@@ -903,7 +900,7 @@ int wcssub(
+@@ -903,7 +901,7 @@ int wcssub(
    }
  
    if ((*nsub = msub) == 0) {
@@ -23642,7 +26252,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
      status = wcsinit(alloc, 0, wcsdst, 0, 0, 0);
      goto cleanup;
    }
-@@ -913,11 +910,11 @@ int wcssub(
+@@ -913,11 +911,11 @@ int wcssub(
    }
  
  
@@ -23659,7 +26269,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    map = itmp;
    for (i = 0; i < naxis; i++) {
      map[i] = 0;
-@@ -930,8 +927,8 @@ int wcssub(
+@@ -930,8 +928,8 @@ int wcssub(
    }
  
  
@@ -23670,7 +26280,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    srcp = wcssrc->pc;
    for (i = 0; i < naxis; i++) {
      for (j = 0; j < naxis; j++) {
-@@ -944,8 +941,8 @@ int wcssub(
+@@ -944,8 +942,8 @@ int wcssub(
      }
    }
  
@@ -23681,7 +26291,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    ndpmax = 0;
    for (m = 0; m < 2; m++) {
      if (m == 0) {
-@@ -959,7 +956,7 @@ int wcssub(
+@@ -959,7 +957,7 @@ int wcssub(
        for (j = 0; j < naxis; j++) {
          if (map[j] == 0) continue;
  
@@ -23690,7 +26300,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          for (jhat = 0; jhat < 32; jhat++) {
            axmap[jhat] = -1;
          }
-@@ -967,7 +964,7 @@ int wcssub(
+@@ -967,7 +965,7 @@ int wcssub(
          Nhat = 0;
          dpsrc = dissrc->dp;
          for (idp = 0; idp < dissrc->ndp; idp++, dpsrc++) {
@@ -23699,7 +26309,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
            if (dpsrc->j != j+1) continue;
            if (dpsrc->field[1] != pq[m]) continue;
            if ((fp = strchr(dpsrc->field, '.')) == 0x0) continue;
-@@ -994,12 +991,12 @@ int wcssub(
+@@ -994,12 +992,12 @@ int wcssub(
            if (axmap[jhat] < 0) {
              axmap[jhat] = jhat;
  
@@ -23714,7 +26324,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
              status = wcserr_set(WCS_ERRMSG(WCSERR_NON_SEPARABLE));
              goto cleanup;
            }
-@@ -1011,7 +1008,7 @@ int wcssub(
+@@ -1011,7 +1009,7 @@ int wcssub(
    }
  
  
@@ -23723,7 +26333,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    npvmax = 0;
    for (m = 0; m < wcssrc->npv; m++) {
      i = wcssrc->pv[m].i;
-@@ -1020,7 +1017,7 @@ int wcssub(
+@@ -1020,7 +1018,7 @@ int wcssub(
      }
    }
  
@@ -23732,7 +26342,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    npsmax = 0;
    for (m = 0; m < wcssrc->nps; m++) {
      i = wcssrc->ps[m].i;
-@@ -1029,7 +1026,7 @@ int wcssub(
+@@ -1029,7 +1027,7 @@ int wcssub(
      }
    }
  
@@ -23741,7 +26351,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    status = wcsinit(alloc, *nsub, wcsdst, npvmax, npsmax, ndpmax);
  
    for (m = 0; m < 2; m++) {
-@@ -1046,7 +1043,7 @@ int wcssub(
+@@ -1046,7 +1044,7 @@ int wcssub(
          return wcserr_set(WCS_ERRMSG(WCSERR_MEMORY));
        }
  
@@ -23750,7 +26360,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        disdst->flag = -1;
        lindist(m+1, &(wcsdst->lin), disdst, ndpmax);
      }
-@@ -1057,7 +1054,7 @@ int wcssub(
+@@ -1057,7 +1055,7 @@ int wcssub(
    }
  
  
@@ -23759,7 +26369,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    srcp = wcssrc->crpix;
    dstp = wcsdst->crpix;
    for (j = 0; j < *nsub; j++, dstp++) {
-@@ -1087,7 +1084,7 @@ int wcssub(
+@@ -1087,7 +1085,7 @@ int wcssub(
      }
    }
  
@@ -23768,7 +26378,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    srcp = wcssrc->crval;
    dstp = wcsdst->crval;
    for (i = 0; i < *nsub; i++, dstp++) {
-@@ -1097,7 +1094,7 @@ int wcssub(
+@@ -1097,7 +1095,7 @@ int wcssub(
      }
    }
  
@@ -23777,7 +26387,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    for (i = 0; i < *nsub; i++) {
      if (axes[i] > 0) {
        k = axes[i] - 1;
-@@ -1106,18 +1103,18 @@ int wcssub(
+@@ -1106,18 +1104,18 @@ int wcssub(
      }
    }
  
@@ -23799,27 +26409,57 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        wcsdst->pv[npv] = wcssrc->pv[m];
        wcsdst->pv[npv].i = 0;
        npv++;
-@@ -1140,7 +1137,7 @@ int wcssub(
+@@ -1140,47 +1138,51 @@ int wcssub(
    }
    wcsdst->nps = nps;
  
 -  /* Alternate linear transformations. */
-+  // Alternate linear transformations.
-   srcp = wcssrc->cd;
-   dstp = wcsdst->cd;
-   for (i = 0; i < *nsub; i++) {
-@@ -1149,8 +1146,8 @@ int wcssub(
-         k = (axes[i]-1)*naxis + (axes[j]-1);
-         *dstp = *(srcp+k);
-       } else if (i == j && wcssrc->altlin & 2) {
+-  srcp = wcssrc->cd;
+-  dstp = wcsdst->cd;
+-  for (i = 0; i < *nsub; i++) {
+-    for (j = 0; j < *nsub; j++, dstp++) {
+-      if (axes[i] > 0 && axes[j] > 0) {
+-        k = (axes[i]-1)*naxis + (axes[j]-1);
+-        *dstp = *(srcp+k);
+-      } else if (i == j && wcssrc->altlin & 2) {
 -        /* A new axis is being created where CDi_ja was present in the input
 -           header, so override the default value of 0 set by wcsinit(). */
-+        // A new axis is being created where CDi_ja was present in the input
-+        // header, so override the default value of 0 set by wcsinit().
-         *dstp = 1.0;
+-        *dstp = 1.0;
++  // Alternate linear transformations.
++  if (wcssrc->cd) {
++    srcp = wcssrc->cd;
++    dstp = wcsdst->cd;
++    for (i = 0; i < *nsub; i++) {
++      for (j = 0; j < *nsub; j++, dstp++) {
++        if (axes[i] > 0 && axes[j] > 0) {
++          k = (axes[i]-1)*naxis + (axes[j]-1);
++          *dstp = *(srcp+k);
++        } else if (i == j && wcssrc->altlin & 2) {
++          // A new axis is being created where CDi_ja was present in the input
++          // header, so override the default value of 0 set by wcsinit().
++          *dstp = 1.0;
++        }
        }
      }
-@@ -1168,7 +1165,7 @@ int wcssub(
+   }
+ 
+-  srcp = wcssrc->crota;
+-  dstp = wcsdst->crota;
+-  for (i = 0; i < *nsub; i++, dstp++) {
+-    if (axes[i] > 0) {
+-      k = axes[i] - 1;
+-      *dstp = *(srcp+k);
++  if (wcssrc->crota) {
++    srcp = wcssrc->crota;
++    dstp = wcsdst->crota;
++    for (i = 0; i < *nsub; i++, dstp++) {
++      if (axes[i] > 0) {
++        k = axes[i] - 1;
++        *dstp = *(srcp+k);
++      }
+     }
+   }
+ 
    wcsdst->altlin = wcssrc->altlin;
    wcsdst->velref = wcssrc->velref;
  
@@ -23828,7 +26468,25 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    strncpy(wcsdst->alt, wcssrc->alt, 4);
    wcsdst->colnum = wcssrc->colnum;
  
-@@ -1236,7 +1233,7 @@ int wcssub(
+   for (i = 0; i < *nsub; i++) {
+     if (axes[i] > 0) {
+       k = axes[i] - 1;
+-      wcsdst->colax[i] = wcssrc->colax[k];
+-      strncpy(wcsdst->cname[i], wcssrc->cname[k], 72);
+-      wcsdst->crder[i] = wcssrc->crder[k];
+-      wcsdst->csyer[i] = wcssrc->csyer[k];
+-      wcsdst->czphs[i] = wcssrc->czphs[k];
+-      wcsdst->cperi[i] = wcssrc->cperi[k];
++      if (wcssrc->colax) wcsdst->colax[i] = wcssrc->colax[k];
++      if (wcssrc->cname) strncpy(wcsdst->cname[i], wcssrc->cname[k], 72);
++      if (wcssrc->crder) wcsdst->crder[i] = wcssrc->crder[k];
++      if (wcssrc->csyer) wcsdst->csyer[i] = wcssrc->csyer[k];
++      if (wcssrc->czphs) wcsdst->czphs[i] = wcssrc->czphs[k];
++      if (wcssrc->cperi) wcsdst->cperi[i] = wcssrc->cperi[k];
+     }
+   }
+ 
+@@ -1236,7 +1238,7 @@ int wcssub(
    wcsdst->velangl = wcssrc->velangl;
  
  
@@ -23837,7 +26495,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if (wcssrc->aux && !wcsdst->aux) {
      if ((wcsdst->aux = calloc(1, sizeof(struct auxprm))) == 0x0) {
        status = wcserr_set(WCS_ERRMSG(WCSERR_MEMORY));
-@@ -1253,10 +1250,10 @@ int wcssub(
+@@ -1253,10 +1255,10 @@ int wcssub(
    }
  
  
@@ -23850,7 +26508,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
      for (m = 0; m < wcssrc->tab[itab].M; m++) {
        i = wcssrc->tab[itab].map[m];
  
-@@ -1268,7 +1265,7 @@ int wcssub(
+@@ -1268,7 +1270,7 @@ int wcssub(
    }
  
    if (wcsdst->ntab) {
@@ -23859,7 +26517,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
      if ((wcsdst->tab = calloc(wcsdst->ntab, sizeof(struct tabprm))) == 0x0) {
        wcsdst->ntab = 0;
  
-@@ -1297,7 +1294,7 @@ int wcssub(
+@@ -1297,7 +1299,7 @@ int wcssub(
    }
  
  
@@ -23868,7 +26526,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    for (m = 0; m < 2; m++) {
      if (m == 0) {
        dissrc = wcssrc->lin.dispre;
-@@ -1310,7 +1307,7 @@ int wcssub(
+@@ -1310,7 +1312,7 @@ int wcssub(
      if (dissrc) {
        disdst->naxis = *nsub;
  
@@ -23877,7 +26535,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        for (j = 0; j < *nsub; j++) {
          if (axes[j] > 0) {
            k = axes[j] - 1;
-@@ -1319,13 +1316,13 @@ int wcssub(
+@@ -1319,13 +1321,13 @@ int wcssub(
          }
        }
  
@@ -23893,7 +26551,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          for (jhat = 0; jhat < 32; jhat++) {
            axmap[jhat] = -1;
          }
-@@ -1352,7 +1349,7 @@ int wcssub(
+@@ -1352,7 +1354,7 @@ int wcssub(
            }
          }
  
@@ -23902,7 +26560,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          dpsrc = dissrc->dp;
          for (idp = 0; idp < dissrc->ndp; idp++, dpsrc++) {
            if (dpsrc->j != axes[j]) continue;
-@@ -1361,7 +1358,7 @@ int wcssub(
+@@ -1361,7 +1363,7 @@ int wcssub(
            fp++;
  
            if (strncmp(fp, "AXIS.", 5) == 0) {
@@ -23911,7 +26569,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
              continue;
            }
  
-@@ -1416,7 +1413,7 @@ cleanup:
+@@ -1416,7 +1418,7 @@ cleanup:
    return status;
  }
  
@@ -23920,7 +26578,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
  int wcscompare(
    int cmp,
-@@ -1445,7 +1442,7 @@ int wcscompare(
+@@ -1445,7 +1447,7 @@ int wcscompare(
    naxis2 = wcs1->naxis*wcs1->naxis;
  
    if (cmp & WCSCOMPARE_CRPIX) {
@@ -23929,7 +26587,34 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    } else if (cmp & WCSCOMPARE_TILING) {
      for (i = 0; i < naxis; ++i) {
        diff = wcs1->crpix[i] - wcs2->crpix[i];
-@@ -1473,7 +1470,7 @@ int wcscompare(
+@@ -1454,43 +1456,43 @@ int wcscompare(
+       }
+     }
+   } else {
+-    if (!wcsutil_Eq(naxis, tol, wcs1->crpix, wcs2->crpix)) {
++    if (!wcsutil_dblEq(naxis, tol, wcs1->crpix, wcs2->crpix)) {
+       return 0;
+     }
+   }
+ 
+-  if (!wcsutil_Eq(naxis2, tol, wcs1->pc, wcs2->pc) ||
+-      !wcsutil_Eq(naxis, tol, wcs1->cdelt, wcs2->cdelt) ||
+-      !wcsutil_Eq(naxis, tol, wcs1->crval, wcs2->crval) ||
++  if (!wcsutil_dblEq(naxis2, tol, wcs1->pc, wcs2->pc) ||
++      !wcsutil_dblEq(naxis, tol, wcs1->cdelt, wcs2->cdelt) ||
++      !wcsutil_dblEq(naxis, tol, wcs1->crval, wcs2->crval) ||
+       !wcsutil_strEq(naxis, wcs1->cunit, wcs2->cunit) ||
+       !wcsutil_strEq(naxis, wcs1->ctype, wcs2->ctype) ||
+-      !wcsutil_Eq(1, tol, &wcs1->lonpole, &wcs2->lonpole) ||
+-      !wcsutil_Eq(1, tol, &wcs1->latpole, &wcs2->latpole) ||
+-      !wcsutil_Eq(1, tol, &wcs1->restfrq, &wcs2->restfrq) ||
+-      !wcsutil_Eq(1, tol, &wcs1->restwav, &wcs2->restwav) ||
++      !wcsutil_dblEq(1, tol, &wcs1->lonpole, &wcs2->lonpole) ||
++      !wcsutil_dblEq(1, tol, &wcs1->latpole, &wcs2->latpole) ||
++      !wcsutil_dblEq(1, tol, &wcs1->restfrq, &wcs2->restfrq) ||
++      !wcsutil_dblEq(1, tol, &wcs1->restwav, &wcs2->restwav) ||
+       wcs1->npv != wcs2->npv ||
+       wcs1->nps != wcs2->nps) {
      return 0;
    }
  
@@ -23938,7 +26623,11 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    for (i = 0; i < wcs1->npv; ++i) {
      for (j = 0; j < wcs2->npv; ++j) {
        if (wcs1->pv[i].i == wcs2->pv[j].i &&
-@@ -1484,13 +1481,13 @@ int wcscompare(
+           wcs1->pv[i].m == wcs2->pv[j].m) {
+-        if (!wcsutil_Eq(1, tol, &wcs1->pv[i].value, &wcs2->pv[j].value)) {
++        if (!wcsutil_dblEq(1, tol, &wcs1->pv[i].value, &wcs2->pv[j].value)) {
+           return 0;
+         }
          break;
        }
      }
@@ -23954,7 +26643,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    for (i = 0; i < wcs1->nps; ++i) {
      for (j = 0; j < wcs2->nps; ++j) {
        if (wcs1->ps[i].i == wcs2->ps[j].i &&
-@@ -1501,7 +1498,7 @@ int wcscompare(
+@@ -1501,15 +1503,15 @@ int wcscompare(
          break;
        }
      }
@@ -23963,16 +26652,106 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
      if (j == wcs2->nps) {
        return 0;
      }
-@@ -1565,7 +1562,7 @@ int wcscompare(
+   }
+ 
+   if (wcs1->flag != WCSSET || wcs2->flag != WCSSET) {
+-    if (!wcsutil_Eq(naxis2, tol, wcs1->cd, wcs2->cd) ||
+-        !wcsutil_Eq(naxis, tol, wcs1->crota, wcs2->crota) ||
++    if (!wcsutil_dblEq(naxis2, tol, wcs1->cd, wcs2->cd) ||
++        !wcsutil_dblEq(naxis, tol, wcs1->crota, wcs2->crota) ||
+         wcs1->altlin != wcs2->altlin ||
+         wcs1->velref != wcs2->velref) {
+       return 0;
+@@ -1521,10 +1523,10 @@ int wcscompare(
+         wcs1->colnum != wcs2->colnum ||
+         !wcsutil_intEq(naxis, wcs1->colax, wcs2->colax) ||
+         !wcsutil_strEq(naxis, wcs1->cname, wcs2->cname) ||
+-        !wcsutil_Eq(naxis, tol, wcs1->crder, wcs2->crder) ||
+-        !wcsutil_Eq(naxis, tol, wcs1->csyer, wcs2->csyer) ||
+-        !wcsutil_Eq(naxis, tol, wcs1->czphs, wcs2->czphs) ||
+-        !wcsutil_Eq(naxis, tol, wcs1->cperi, wcs2->cperi) ||
++        !wcsutil_dblEq(naxis, tol, wcs1->crder, wcs2->crder) ||
++        !wcsutil_dblEq(naxis, tol, wcs1->csyer, wcs2->csyer) ||
++        !wcsutil_dblEq(naxis, tol, wcs1->czphs, wcs2->czphs) ||
++        !wcsutil_dblEq(naxis, tol, wcs1->cperi, wcs2->cperi) ||
+         strncmp(wcs1->wcsname,  wcs2->wcsname,  72) ||
+         strncmp(wcs1->timesys,  wcs2->timesys,  72) ||
+         strncmp(wcs1->trefpos,  wcs2->trefpos,  72) ||
+@@ -1532,46 +1534,46 @@ int wcscompare(
+         strncmp(wcs1->plephem,  wcs2->plephem,  72) ||
+         strncmp(wcs1->timeunit, wcs2->timeunit, 72) ||
+         strncmp(wcs1->dateref,  wcs2->dateref,  72) ||
+-        !wcsutil_Eq(2, tol,  wcs1->mjdref,    wcs2->mjdref)   ||
+-        !wcsutil_Eq(1, tol, &wcs1->timeoffs, &wcs2->timeoffs) ||
++        !wcsutil_dblEq(2, tol,  wcs1->mjdref,    wcs2->mjdref)   ||
++        !wcsutil_dblEq(1, tol, &wcs1->timeoffs, &wcs2->timeoffs) ||
+         strncmp(wcs1->dateobs,  wcs2->dateobs, 72) ||
+         strncmp(wcs1->datebeg,  wcs2->datebeg, 72) ||
+         strncmp(wcs1->dateavg,  wcs2->dateavg, 72) ||
+         strncmp(wcs1->dateend,  wcs2->dateend, 72) ||
+-        !wcsutil_Eq(1, tol, &wcs1->mjdobs,   &wcs2->mjdobs)   ||
+-        !wcsutil_Eq(1, tol, &wcs1->mjdbeg,   &wcs2->mjdbeg)   ||
+-        !wcsutil_Eq(1, tol, &wcs1->mjdavg,   &wcs2->mjdavg)   ||
+-        !wcsutil_Eq(1, tol, &wcs1->mjdend,   &wcs2->mjdend)   ||
+-        !wcsutil_Eq(1, tol, &wcs1->jepoch,   &wcs2->jepoch)   ||
+-        !wcsutil_Eq(1, tol, &wcs1->bepoch,   &wcs2->bepoch)   ||
+-        !wcsutil_Eq(1, tol, &wcs1->tstart,   &wcs2->tstart)   ||
+-        !wcsutil_Eq(1, tol, &wcs1->tstop,    &wcs2->tstop)    ||
+-        !wcsutil_Eq(1, tol, &wcs1->xposure,  &wcs2->xposure)  ||
+-        !wcsutil_Eq(1, tol, &wcs1->telapse,  &wcs2->telapse)  ||
+-        !wcsutil_Eq(1, tol, &wcs1->timsyer,  &wcs2->timsyer)  ||
+-        !wcsutil_Eq(1, tol, &wcs1->timrder,  &wcs2->timrder)  ||
+-        !wcsutil_Eq(1, tol, &wcs1->timedel,  &wcs2->timedel)  ||
+-        !wcsutil_Eq(1, tol, &wcs1->timepixr, &wcs2->timepixr) ||
+-        !wcsutil_Eq(6, tol,  wcs1->obsgeo,    wcs2->obsgeo)   ||
++        !wcsutil_dblEq(1, tol, &wcs1->mjdobs,   &wcs2->mjdobs)   ||
++        !wcsutil_dblEq(1, tol, &wcs1->mjdbeg,   &wcs2->mjdbeg)   ||
++        !wcsutil_dblEq(1, tol, &wcs1->mjdavg,   &wcs2->mjdavg)   ||
++        !wcsutil_dblEq(1, tol, &wcs1->mjdend,   &wcs2->mjdend)   ||
++        !wcsutil_dblEq(1, tol, &wcs1->jepoch,   &wcs2->jepoch)   ||
++        !wcsutil_dblEq(1, tol, &wcs1->bepoch,   &wcs2->bepoch)   ||
++        !wcsutil_dblEq(1, tol, &wcs1->tstart,   &wcs2->tstart)   ||
++        !wcsutil_dblEq(1, tol, &wcs1->tstop,    &wcs2->tstop)    ||
++        !wcsutil_dblEq(1, tol, &wcs1->xposure,  &wcs2->xposure)  ||
++        !wcsutil_dblEq(1, tol, &wcs1->telapse,  &wcs2->telapse)  ||
++        !wcsutil_dblEq(1, tol, &wcs1->timsyer,  &wcs2->timsyer)  ||
++        !wcsutil_dblEq(1, tol, &wcs1->timrder,  &wcs2->timrder)  ||
++        !wcsutil_dblEq(1, tol, &wcs1->timedel,  &wcs2->timedel)  ||
++        !wcsutil_dblEq(1, tol, &wcs1->timepixr, &wcs2->timepixr) ||
++        !wcsutil_dblEq(6, tol,  wcs1->obsgeo,    wcs2->obsgeo)   ||
+         strncmp(wcs1->obsorbit, wcs2->obsorbit, 72) ||
+         strncmp(wcs1->radesys,  wcs2->radesys,  72) ||
+-        !wcsutil_Eq(1, tol, &wcs1->equinox,  &wcs2->equinox)  ||
++        !wcsutil_dblEq(1, tol, &wcs1->equinox,  &wcs2->equinox)  ||
+         strncmp(wcs1->specsys,  wcs2->specsys,  72) ||
+         strncmp(wcs1->ssysobs,  wcs2->ssysobs,  72) ||
+-        !wcsutil_Eq(1, tol, &wcs1->velosys,  &wcs2->velosys)  ||
+-        !wcsutil_Eq(1, tol, &wcs1->zsource,  &wcs2->zsource)  ||
++        !wcsutil_dblEq(1, tol, &wcs1->velosys,  &wcs2->velosys)  ||
++        !wcsutil_dblEq(1, tol, &wcs1->zsource,  &wcs2->zsource)  ||
+         strncmp(wcs1->ssyssrc,  wcs2->ssyssrc,  72) ||
+-        !wcsutil_Eq(1, tol, &wcs1->velangl,  &wcs2->velangl)) {
++        !wcsutil_dblEq(1, tol, &wcs1->velangl,  &wcs2->velangl)) {
        return 0;
      }
  
 -    /* Compare additional auxiliary parameters. */
 +    // Compare additional auxiliary parameters.
      if (wcs1->aux && wcs2->aux) {
-       if (!wcsutil_Eq(1, tol, &wcs1->aux->rsun_ref, &wcs2->aux->rsun_ref) ||
-           !wcsutil_Eq(1, tol, &wcs1->aux->dsun_obs, &wcs2->aux->dsun_obs) ||
-@@ -1579,7 +1576,7 @@ int wcscompare(
+-      if (!wcsutil_Eq(1, tol, &wcs1->aux->rsun_ref, &wcs2->aux->rsun_ref) ||
+-          !wcsutil_Eq(1, tol, &wcs1->aux->dsun_obs, &wcs2->aux->dsun_obs) ||
+-          !wcsutil_Eq(1, tol, &wcs1->aux->crln_obs, &wcs2->aux->crln_obs) ||
+-          !wcsutil_Eq(1, tol, &wcs1->aux->hgln_obs, &wcs2->aux->hgln_obs) ||
+-          !wcsutil_Eq(1, tol, &wcs1->aux->hglt_obs, &wcs2->aux->hglt_obs)) {
++      if (!wcsutil_dblEq(1, tol, &wcs1->aux->rsun_ref, &wcs2->aux->rsun_ref) ||
++          !wcsutil_dblEq(1, tol, &wcs1->aux->dsun_obs, &wcs2->aux->dsun_obs) ||
++          !wcsutil_dblEq(1, tol, &wcs1->aux->crln_obs, &wcs2->aux->crln_obs) ||
++          !wcsutil_dblEq(1, tol, &wcs1->aux->hgln_obs, &wcs2->aux->hgln_obs) ||
++          !wcsutil_dblEq(1, tol, &wcs1->aux->hglt_obs, &wcs2->aux->hglt_obs)) {
+         return 0;
+       }
+     } else if (wcs1->aux || wcs2->aux) {
+@@ -1579,7 +1581,7 @@ int wcscompare(
      }
    }
  
@@ -23981,7 +26760,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if (wcs1->ntab != wcs2->ntab) {
      return 0;
    }
-@@ -1597,7 +1594,7 @@ int wcscompare(
+@@ -1597,22 +1599,20 @@ int wcscompare(
    return 0;
  }
  
@@ -23990,7 +26769,12 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
  int wcsfree(struct wcsprm *wcs)
  
-@@ -1610,9 +1607,9 @@ int wcsfree(struct wcsprm *wcs)
+ {
+-  int j;
+-
+   if (wcs == 0x0) return WCSERR_NULL_POINTER;
+ 
+   if (wcs->flag == -1) {
      wcs->lin.flag = -1;
  
    } else {
@@ -24002,7 +26786,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        if (wcs->crpix == wcs->m_crpix) wcs->crpix = 0x0;
        if (wcs->pc    == wcs->m_pc)    wcs->pc    = 0x0;
        if (wcs->cdelt == wcs->m_cdelt) wcs->cdelt = 0x0;
-@@ -1634,7 +1631,7 @@ int wcsfree(struct wcsprm *wcs)
+@@ -1634,7 +1634,7 @@ int wcsfree(struct wcsprm *wcs)
        if (wcs->tab   == wcs->m_tab)   wcs->tab   = 0x0;
        if (wcs->wtb   == wcs->m_wtb)   wcs->wtb   = 0x0;
  
@@ -24011,7 +26795,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        if (wcs->m_crpix)  free(wcs->m_crpix);
        if (wcs->m_pc)     free(wcs->m_pc);
        if (wcs->m_cdelt)  free(wcs->m_cdelt);
-@@ -1652,10 +1649,10 @@ int wcsfree(struct wcsprm *wcs)
+@@ -1652,13 +1652,13 @@ int wcsfree(struct wcsprm *wcs)
        if (wcs->m_czphs)  free(wcs->m_czphs);
        if (wcs->m_cperi)  free(wcs->m_cperi);
  
@@ -24022,9 +26806,14 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
 -      /* Allocated unconditionally by wcstab(). */
 +      // Allocated unconditionally by wcstab().
        if (wcs->m_tab) {
-         for (j = 0; j < wcs->ntab; j++) {
-           tabfree(wcs->m_tab + j);
-@@ -1666,7 +1663,7 @@ int wcsfree(struct wcsprm *wcs)
+-        for (j = 0; j < wcs->ntab; j++) {
+-          tabfree(wcs->m_tab + j);
++        for (int itab = 0; itab < wcs->ntab; itab++) {
++          tabfree(wcs->m_tab + itab);
+         }
+ 
+         free(wcs->m_tab);
+@@ -1666,7 +1666,7 @@ int wcsfree(struct wcsprm *wcs)
        if (wcs->m_wtb) free(wcs->m_wtb);
      }
  
@@ -24033,25 +26822,297 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
      if (wcs->types) free(wcs->types);
  
      if (wcs->lin.crpix == wcs->m_crpix) wcs->lin.crpix = 0x0;
-@@ -1713,7 +1710,7 @@ int wcsfree(struct wcsprm *wcs)
-   return 0;
+@@ -1710,10 +1710,251 @@ int wcsfree(struct wcsprm *wcs)
+   celfree(&(wcs->cel));
+   spcfree(&(wcs->spc));
+ 
+-  return 0;
++  return WCSERR_SUCCESS;
++}
++
++//----------------------------------------------------------------------------
++
++int wcstrim(struct wcsprm *wcs)
++
++{
++  if (wcs == 0x0) return WCSERR_NULL_POINTER;
++
++  if (wcs->m_flag != WCSSET) {
++    // Nothing to do.
++    return WCSERR_SUCCESS;
++  }
++
++  if (wcs->flag != WCSSET) {
++    return WCSERR_UNSET;
++  }
++
++  if (wcs->npv < wcs->npvmax) {
++    if (wcs->m_pv) {
++      if (wcs->npv == 0) {
++        free(wcs->m_pv);
++        wcs->pv = wcs->m_pv = 0x0;
++      } else {
++        size_t size = wcs->npv * sizeof(struct pvcard);
++        // No error if realloc() fails, it will leave the array untouched.
++        if ((wcs->pv = wcs->m_pv = realloc(wcs->m_pv, size))) {
++          wcs->npvmax = wcs->npv;
++        }
++      }
++    }
++  }
++
++  if (wcs->nps < wcs->npsmax) {
++    if (wcs->m_ps) {
++      if (wcs->nps == 0) {
++        free(wcs->m_ps);
++        wcs->ps = wcs->m_ps = 0x0;
++      } else {
++        size_t size = wcs->nps * sizeof(struct pscard);
++        // No error if realloc() fails, it will leave the array untouched.
++        if ((wcs->ps = wcs->m_ps = realloc(wcs->m_ps, size))) {
++          wcs->npsmax = wcs->nps;
++        }
++      }
++    }
++  }
++
++  if (!(wcs->altlin & 2)) {
++    if (wcs->m_cd) {
++      free(wcs->m_cd);
++      wcs->cd = wcs->m_cd = 0x0;
++    }
++  }
++
++  if (!(wcs->altlin & 4)) {
++    if (wcs->m_crota) {
++      free(wcs->m_crota);
++      wcs->crota = wcs->m_crota = 0x0;
++    }
++  }
++
++  if (wcs->colax) {
++    if (wcsutil_all_ival(wcs->naxis, 0, wcs->colax)) {
++      free(wcs->m_colax);
++      wcs->colax = wcs->m_colax = 0x0;
++    }
++  }
++
++  if (wcs->cname) {
++    if (wcsutil_all_sval(wcs->naxis, "", wcs->cname)) {
++      free(wcs->m_cname);
++      wcs->cname = wcs->m_cname = 0x0;
++    }
++  }
++
++  if (wcs->crder) {
++    if (wcsutil_all_dval(wcs->naxis, UNDEFINED, wcs->crder)) {
++      free(wcs->m_crder);
++      wcs->crder = wcs->m_crder = 0x0;
++    }
++  }
++
++  if (wcs->csyer) {
++    if (wcsutil_all_dval(wcs->naxis, UNDEFINED, wcs->csyer)) {
++      free(wcs->m_csyer);
++      wcs->csyer = wcs->m_csyer = 0x0;
++    }
++  }
++
++  if (wcs->czphs) {
++    if (wcsutil_all_dval(wcs->naxis, UNDEFINED, wcs->czphs)) {
++      free(wcs->m_czphs);
++      wcs->czphs = wcs->m_czphs = 0x0;
++    }
++  }
++
++  if (wcs->cperi) {
++    if (wcsutil_all_dval(wcs->naxis, UNDEFINED, wcs->cperi)) {
++      free(wcs->m_cperi);
++      wcs->cperi = wcs->m_cperi = 0x0;
++    }
++  }
++
++  return WCSERR_SUCCESS;
  }
  
 -/*--------------------------------------------------------------------------*/
++//----------------------------------------------------------------------------
++
++int wcssize(const struct wcsprm *wcs, int sizes[2])
++
++{
++  if (wcs == 0x0) {
++    sizes[0] = sizes[1] = 0;
++    return WCSERR_SUCCESS;
++  }
++
++  // Base size, in bytes.
++  sizes[0] = sizeof(struct wcsprm);
++
++  // Total size of allocated memory, in bytes.
++  sizes[1] = 0;
++
++  int exsizes[2];
++  int naxis = wcs->naxis;
++
++  // wcsprm::crpix[].
++  sizes[1] += naxis * sizeof(double);
++
++  // wcsprm::pc[].
++  sizes[1] += naxis*naxis * sizeof(double);
++
++  // wcsprm::cdelt[].
++  sizes[1] += naxis * sizeof(double);
++
++  // wcsprm::crval[].
++  sizes[1] += naxis * sizeof(double);
++
++  // wcsprm::cunit[].
++  if (wcs->cunit) {
++    sizes[1] += naxis * sizeof(char [72]);
++  }
++
++  // wcsprm::ctype[].
++  sizes[1] += naxis * sizeof(char [72]);
++
++  // wcsprm::pv[].
++  if (wcs->pv) {
++    sizes[1] += wcs->npvmax * sizeof(struct pvcard);
++  }
++
++  // wcsprm::ps[].
++  if (wcs->ps) {
++    sizes[1] += wcs->npsmax * sizeof(struct pscard);
++  }
++
++  // wcsprm::cd[].
++  if (wcs->cd) {
++    sizes[1] += naxis*naxis * sizeof(double);
++  }
++
++  // wcsprm::crota[].
++  if (wcs->crota) {
++    sizes[1] += naxis * sizeof(double);
++  }
++
++  // wcsprm::colax[].
++  if (wcs->colax) {
++    sizes[1] += naxis * sizeof(int);
++  }
++
++  // wcsprm::cname[].
++  if (wcs->cname) {
++    sizes[1] += naxis * sizeof(char [72]);
++  }
++
++  // wcsprm::crder[].
++  if (wcs->crder) {
++    sizes[1] += naxis * sizeof(double);
++  }
++
++  // wcsprm::csyer[].
++  if (wcs->csyer) {
++    sizes[1] += naxis * sizeof(double);
++  }
++
++  // wcsprm::czphs[].
++  if (wcs->czphs) {
++    sizes[1] += naxis * sizeof(double);
++  }
++
++  // wcsprm::cperi[].
++  if (wcs->cperi) {
++    sizes[1] += naxis * sizeof(double);
++  }
++
++  // wcsprm::aux.
++  if (wcs->aux) {
++    sizes[1] += sizeof(struct auxprm);
++  }
++
++  // wcsprm::tab.
++  for (int itab = 0; itab < wcs->ntab; itab++) {
++    tabsize(wcs->tab + itab, exsizes);
++    sizes[1] += exsizes[0] + exsizes[1];
++  }
++
++  // wcsprm::wtb.
++  if (wcs->wtb) {
++    sizes[1] += wcs->nwtb * sizeof(struct wtbarr);
++  }
++
++  // wcsprm::lin.
++  linsize(&(wcs->lin), exsizes);
++  sizes[1] += exsizes[1];
++
++  // wcsprm::err.
++  wcserr_size(wcs->err, exsizes);
++  sizes[1] += exsizes[0] + exsizes[1];
++
++  return WCSERR_SUCCESS;
++}
++
++//----------------------------------------------------------------------------
++
++int auxsize(const struct auxprm *aux, int sizes[2])
++
++{
++  if (aux == 0x0) {
++    sizes[0] = sizes[1] = 0;
++    return WCSERR_SUCCESS;
++  }
++
++  // Base size, in bytes.
++  sizes[0] = sizeof(struct auxprm);
++
++  // Total size of allocated memory, in bytes.
++  sizes[1] = 0;
++
++  return WCSERR_SUCCESS;
++}
++
++
 +//----------------------------------------------------------------------------
  
  static void wcsprt_auxc(const char *name, const char *value)
  {
-@@ -1755,7 +1752,7 @@ int wcsprt(const struct wcsprm *wcs)
+@@ -1736,64 +1977,61 @@ static void wcsprt_auxd(const char *name
+ int wcsprt(const struct wcsprm *wcs)
+ 
+ {
+-  int i, j, k;
+-  struct wtbarr *wtbp;
+-
+   if (wcs == 0x0) return WCSERR_NULL_POINTER;
+ 
+   if (wcs->flag != WCSSET) {
+     wcsprintf("The wcsprm struct is UNINITIALIZED.\n");
+-    return 0;
++    return WCSERR_SUCCESS;
+   }
+ 
+   wcsprintf("       flag: %d\n", wcs->flag);
+   wcsprintf("      naxis: %d\n", wcs->naxis);
+   WCSPRINTF_PTR("      crpix: ", wcs->crpix, "\n");
+   wcsprintf("            ");
+-  for (i = 0; i < wcs->naxis; i++) {
++  for (int i = 0; i < wcs->naxis; i++) {
+     wcsprintf("  %#- 11.5g", wcs->crpix[i]);
    }
    wcsprintf("\n");
  
 -  /* Linear transformation. */
+-  k = 0;
 +  // Linear transformation.
-   k = 0;
++  int k = 0;
    WCSPRINTF_PTR("         pc: ", wcs->pc, "\n");
-   for (i = 0; i < wcs->naxis; i++) {
-@@ -1766,7 +1763,7 @@ int wcsprt(const struct wcsprm *wcs)
+-  for (i = 0; i < wcs->naxis; i++) {
++  for (int i = 0; i < wcs->naxis; i++) {
+     wcsprintf("    pc[%d][]:", i);
+-    for (j = 0; j < wcs->naxis; j++) {
++    for (int j = 0; j < wcs->naxis; j++) {
+       wcsprintf("  %#- 11.5g", wcs->pc[k++]);
+     }
      wcsprintf("\n");
    }
  
@@ -24059,8 +27120,9 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
 +  // Coordinate increment at reference point.
    WCSPRINTF_PTR("      cdelt: ", wcs->cdelt, "\n");
    wcsprintf("            ");
-   for (i = 0; i < wcs->naxis; i++) {
-@@ -1774,7 +1771,7 @@ int wcsprt(const struct wcsprm *wcs)
+-  for (i = 0; i < wcs->naxis; i++) {
++  for (int i = 0; i < wcs->naxis; i++) {
+     wcsprintf("  %#- 11.5g", wcs->cdelt[i]);
    }
    wcsprintf("\n");
  
@@ -24068,17 +27130,23 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
 +  // Coordinate value at reference point.
    WCSPRINTF_PTR("      crval: ", wcs->crval, "\n");
    wcsprintf("            ");
-   for (i = 0; i < wcs->naxis; i++) {
-@@ -1782,7 +1779,7 @@ int wcsprt(const struct wcsprm *wcs)
+-  for (i = 0; i < wcs->naxis; i++) {
++  for (int i = 0; i < wcs->naxis; i++) {
+     wcsprintf("  %#- 11.5g", wcs->crval[i]);
    }
    wcsprintf("\n");
  
 -  /* Coordinate units and type. */
 +  // Coordinate units and type.
    WCSPRINTF_PTR("      cunit: ", wcs->cunit, "\n");
-   for (i = 0; i < wcs->naxis; i++) {
+-  for (i = 0; i < wcs->naxis; i++) {
++  for (int i = 0; i < wcs->naxis; i++) {
      wcsprintf("             \"%s\"\n", wcs->cunit[i]);
-@@ -1793,7 +1790,7 @@ int wcsprt(const struct wcsprm *wcs)
+   }
+ 
+   WCSPRINTF_PTR("      ctype: ", wcs->ctype, "\n");
+-  for (i = 0; i < wcs->naxis; i++) {
++  for (int i = 0; i < wcs->naxis; i++) {
      wcsprintf("             \"%s\"\n", wcs->ctype[i]);
    }
  
@@ -24087,7 +27155,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if (undefined(wcs->lonpole)) {
      wcsprintf("    lonpole: UNDEFINED\n");
    } else {
-@@ -1803,7 +1800,7 @@ int wcsprt(const struct wcsprm *wcs)
+@@ -1803,29 +2041,29 @@ int wcsprt(const struct wcsprm *wcs)
    wcsprintf("    restfrq: %f\n", wcs->restfrq);
    wcsprintf("    restwav: %f\n", wcs->restwav);
  
@@ -24096,8 +27164,22 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    wcsprintf("        npv: %d\n", wcs->npv);
    wcsprintf("     npvmax: %d\n", wcs->npvmax);
    WCSPRINTF_PTR("         pv: ", wcs->pv, "\n");
-@@ -1819,7 +1816,7 @@ int wcsprt(const struct wcsprm *wcs)
-       (wcs->ps[i]).m, (wcs->ps[i]).value);
+-  for (i = 0; i < wcs->npv; i++) {
+-    wcsprintf("             %3d%4d  %#- 11.5g\n", (wcs->pv[i]).i,
+-      (wcs->pv[i]).m, (wcs->pv[i]).value);
++  for (int k = 0; k < wcs->npv; k++) {
++    wcsprintf("             %3d%4d  %#- 11.5g\n", (wcs->pv[k]).i,
++      (wcs->pv[k]).m, (wcs->pv[k]).value);
+   }
+   wcsprintf("        nps: %d\n", wcs->nps);
+   wcsprintf("     npsmax: %d\n", wcs->npsmax);
+   WCSPRINTF_PTR("         ps: ", wcs->ps, "\n");
+-  for (i = 0; i < wcs->nps; i++) {
+-    wcsprintf("             %3d%4d  %s\n", (wcs->ps[i]).i,
+-      (wcs->ps[i]).m, (wcs->ps[i]).value);
++  for (int k = 0; k < wcs->nps; k++) {
++    wcsprintf("             %3d%4d  %s\n", (wcs->ps[k]).i,
++      (wcs->ps[k]).m, (wcs->ps[k]).value);
    }
  
 -  /* Alternate linear transformations. */
@@ -24105,7 +27187,24 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    k = 0;
    WCSPRINTF_PTR("         cd: ", wcs->cd, "\n");
    if (wcs->cd) {
-@@ -1846,7 +1843,7 @@ int wcsprt(const struct wcsprm *wcs)
+-    for (i = 0; i < wcs->naxis; i++) {
++    for (int i = 0; i < wcs->naxis; i++) {
+       wcsprintf("    cd[%d][]:", i);
+-      for (j = 0; j < wcs->naxis; j++) {
++      for (int j = 0; j < wcs->naxis; j++) {
+         wcsprintf("  %#- 11.5g", wcs->cd[k++]);
+       }
+       wcsprintf("\n");
+@@ -1835,7 +2073,7 @@ int wcsprt(const struct wcsprm *wcs)
+   WCSPRINTF_PTR("      crota: ", wcs->crota, "\n");
+   if (wcs->crota) {
+     wcsprintf("            ");
+-    for (i = 0; i < wcs->naxis; i++) {
++    for (int i = 0; i < wcs->naxis; i++) {
+       wcsprintf("  %#- 11.5g", wcs->crota[i]);
+     }
+     wcsprintf("\n");
+@@ -1846,14 +2084,14 @@ int wcsprt(const struct wcsprm *wcs)
  
  
  
@@ -24114,7 +27213,101 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    wcsprintf("        alt: '%c'\n", wcs->alt[0]);
    wcsprintf("     colnum: %d\n", wcs->colnum);
  
-@@ -1990,7 +1987,7 @@ int wcsprt(const struct wcsprm *wcs)
+   WCSPRINTF_PTR("      colax: ", wcs->colax, "\n");
+   if (wcs->colax) {
+     wcsprintf("           ");
+-    for (i = 0; i < wcs->naxis; i++) {
++    for (int i = 0; i < wcs->naxis; i++) {
+       wcsprintf("  %5d", wcs->colax[i]);
+     }
+     wcsprintf("\n");
+@@ -1861,7 +2099,7 @@ int wcsprt(const struct wcsprm *wcs)
+ 
+   WCSPRINTF_PTR("      cname: ", wcs->cname, "\n");
+   if (wcs->cname) {
+-    for (i = 0; i < wcs->naxis; i++) {
++    for (int i = 0; i < wcs->naxis; i++) {
+       if (wcs->cname[i][0] == '\0') {
+         wcsprintf("             UNDEFINED\n");
+       } else {
+@@ -1873,7 +2111,7 @@ int wcsprt(const struct wcsprm *wcs)
+   WCSPRINTF_PTR("      crder: ", wcs->crder, "\n");
+   if (wcs->crder) {
+     wcsprintf("           ");
+-    for (i = 0; i < wcs->naxis; i++) {
++    for (int i = 0; i < wcs->naxis; i++) {
+       if (undefined(wcs->crder[i])) {
+         wcsprintf("    UNDEFINED");
+       } else {
+@@ -1886,7 +2124,7 @@ int wcsprt(const struct wcsprm *wcs)
+   WCSPRINTF_PTR("      csyer: ", wcs->csyer, "\n");
+   if (wcs->csyer) {
+     wcsprintf("           ");
+-    for (i = 0; i < wcs->naxis; i++) {
++    for (int i = 0; i < wcs->naxis; i++) {
+       if (undefined(wcs->csyer[i])) {
+         wcsprintf("    UNDEFINED");
+       } else {
+@@ -1899,7 +2137,7 @@ int wcsprt(const struct wcsprm *wcs)
+   WCSPRINTF_PTR("      czphs: ", wcs->czphs, "\n");
+   if (wcs->czphs) {
+     wcsprintf("           ");
+-    for (i = 0; i < wcs->naxis; i++) {
++    for (int i = 0; i < wcs->naxis; i++) {
+       if (undefined(wcs->czphs[i])) {
+         wcsprintf("    UNDEFINED");
+       } else {
+@@ -1912,7 +2150,7 @@ int wcsprt(const struct wcsprm *wcs)
+   WCSPRINTF_PTR("      cperi: ", wcs->cperi, "\n");
+   if (wcs->cperi) {
+     wcsprintf("           ");
+-    for (i = 0; i < wcs->naxis; i++) {
++    for (int i = 0; i < wcs->naxis; i++) {
+       if (undefined(wcs->cperi[i])) {
+         wcsprintf("    UNDEFINED");
+       } else {
+@@ -1931,11 +2169,11 @@ int wcsprt(const struct wcsprm *wcs)
+   wcsprt_auxc("timeunit", wcs->timeunit);
+   wcsprt_auxc(" dateref", wcs->dateref);
+   wcsprintf("     mjdref: ");
+-  for (i = 0; i < 2; i++) {
+-    if (undefined(wcs->mjdref[i])) {
++  for (int k = 0; k < 2; k++) {
++    if (undefined(wcs->mjdref[k])) {
+       wcsprintf("       UNDEFINED");
+     } else {
+-      wcsprintf(" %15.9f", wcs->mjdref[i]);
++      wcsprintf(" %15.9f", wcs->mjdref[k]);
+     }
+   }
+   wcsprintf("\n");
+@@ -1963,19 +2201,19 @@ int wcsprt(const struct wcsprm *wcs)
+   wcsprt_auxd("timepixr", wcs->timepixr);
+ 
+   wcsprintf("     obsgeo: ");
+-  for (i = 0; i < 3; i++) {
+-    if (undefined(wcs->obsgeo[i])) {
++  for (int k = 0; k < 3; k++) {
++    if (undefined(wcs->obsgeo[k])) {
+       wcsprintf("       UNDEFINED");
+     } else {
+-      wcsprintf(" %15.6f", wcs->obsgeo[i]);
++      wcsprintf(" %15.6f", wcs->obsgeo[k]);
+     }
+   }
+   wcsprintf("\n             ");
+-  for (i = 3; i < 6; i++) {
+-    if (undefined(wcs->obsgeo[i])) {
++  for (int k = 3; k < 6; k++) {
++    if (undefined(wcs->obsgeo[k])) {
+       wcsprintf("       UNDEFINED");
+     } else {
+-      wcsprintf(" %15.6f", wcs->obsgeo[i]);
++      wcsprintf(" %15.6f", wcs->obsgeo[k]);
+     }
+   }
+   wcsprintf("\n");
+@@ -1990,7 +2228,7 @@ int wcsprt(const struct wcsprm *wcs)
    wcsprt_auxc(" ssyssrc", wcs->ssyssrc);
    wcsprt_auxd(" velangl", wcs->velangl);
  
@@ -24123,16 +27316,19 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    WCSPRINTF_PTR("        aux: ", wcs->aux, "\n");
    if (wcs->aux) {
      wcsprt_auxd("rsun_ref", wcs->aux->rsun_ref);
-@@ -2009,7 +2006,7 @@ int wcsprt(const struct wcsprm *wcs)
+@@ -2009,9 +2247,9 @@ int wcsprt(const struct wcsprm *wcs)
    if (wcs->wtb != 0x0) wcsprintf("  (see below)");
    wcsprintf("\n");
  
 -  /* Derived values. */
 +  // Derived values.
    WCSPRINTF_PTR("      types: ", wcs->types, "\n           ");
-   for (i = 0; i < wcs->naxis; i++) {
+-  for (i = 0; i < wcs->naxis; i++) {
++  for (int i = 0; i < wcs->naxis; i++) {
      wcsprintf("%5d", wcs->types[i]);
-@@ -2032,7 +2029,7 @@ int wcsprt(const struct wcsprm *wcs)
+   }
+   wcsprintf("\n");
+@@ -2032,7 +2270,7 @@ int wcsprt(const struct wcsprm *wcs)
    wcsprintf("        cel: (see below)\n");
    wcsprintf("        spc: (see below)\n");
  
@@ -24141,16 +27337,34 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    wcsprintf("     m_flag: %d\n", wcs->m_flag);
    wcsprintf("    m_naxis: %d\n", wcs->m_naxis);
    WCSPRINTF_PTR("    m_crpix: ", wcs->m_crpix, "");
-@@ -2094,7 +2091,7 @@ int wcsprt(const struct wcsprm *wcs)
+@@ -2094,11 +2332,12 @@ int wcsprt(const struct wcsprm *wcs)
    if (wcs->m_wtb == wcs->wtb) wcsprintf("  (= wtb)");
    wcsprintf("\n");
  
 -  /* Tabular transformation parameters. */
+-  if ((wtbp = wcs->wtb)) {
+-    for (j = 0; j < wcs->nwtb; j++, wtbp++) {
 +  // Tabular transformation parameters.
-   if ((wtbp = wcs->wtb)) {
-     for (j = 0; j < wcs->nwtb; j++, wtbp++) {
++  struct wtbarr *wtbp = wcs->wtb;
++  if (wtbp) {
++    for (int iwtb = 0; iwtb < wcs->nwtb; iwtb++, wtbp++) {
        wcsprintf("\n");
-@@ -2122,17 +2119,17 @@ int wcsprt(const struct wcsprm *wcs)
+-      wcsprintf("wtb[%d].*\n", j);
++      wcsprintf("wtb[%d].*\n", iwtb);
+       wcsprintf("          i: %d\n", wtbp->i);
+       wcsprintf("          m: %d\n", wtbp->m);
+       wcsprintf("       kind: %c\n", wtbp->kind);
+@@ -2115,38 +2354,36 @@ int wcsprt(const struct wcsprm *wcs)
+   }
+ 
+   if (wcs->tab) {
+-    for (j = 0; j < wcs->ntab; j++) {
++    for (int itab = 0; itab < wcs->ntab; itab++) {
+       wcsprintf("\n");
+-      wcsprintf("tab[%d].*\n", j);
+-      tabprt(wcs->tab + j);
++      wcsprintf("tab[%d].*\n", itab);
++      tabprt(wcs->tab + itab);
      }
    }
  
@@ -24171,8 +27385,9 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    wcsprintf("\n");
    wcsprintf("   spc.*\n");
    spcprt(&(wcs->spc));
-@@ -2140,7 +2137,7 @@ int wcsprt(const struct wcsprm *wcs)
-   return 0;
+ 
+-  return 0;
++  return WCSERR_SUCCESS;
  }
  
 -/*--------------------------------------------------------------------------*/
@@ -24180,8 +27395,26 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
  int wcsperr(const struct wcsprm *wcs, const char *prefix)
  
-@@ -2163,7 +2160,7 @@ int wcsperr(const struct wcsprm *wcs, co
-   return 0;
+ {
+-  int j;
+-
+   if (wcs == 0x0) return WCSERR_NULL_POINTER;
+ 
+   if (wcs->err && wcserr_prt(wcs->err, prefix) == 0) {
+@@ -2154,113 +2391,105 @@ int wcsperr(const struct wcsprm *wcs, co
+     celperr(&(wcs->cel), prefix);
+     wcserr_prt(wcs->spc.err, prefix);
+     if (wcs->tab) {
+-      for (j = 0; j < wcs->ntab; j++) {
+-        wcserr_prt((wcs->tab + j)->err, prefix);
++      for (int itab = 0; itab < wcs->ntab; itab++) {
++        wcserr_prt((wcs->tab + itab)->err, prefix);
+       }
+     }
+   }
+ 
+-  return 0;
++  return WCSERR_SUCCESS;
  }
  
 -/*--------------------------------------------------------------------------*/
@@ -24189,8 +27422,20 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
  int wcsbchk(struct wcsprm *wcs, int bounds)
  
-@@ -2181,7 +2178,7 @@ int wcsbchk(struct wcsprm *wcs, int boun
-   return 0;
+ {
+-  int status;
+-
+   if (wcs == 0x0) return WCSERR_NULL_POINTER;
+ 
+   if (wcs->flag != WCSSET) {
++    int status;
+     if ((status = wcsset(wcs))) return status;
+   }
+ 
+   wcs->cel.prj.bounds = bounds;
+ 
+-  return 0;
++  return WCSERR_SUCCESS;
  }
  
 -/*--------------------------------------------------------------------------*/
@@ -24198,12 +27443,29 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
  int wcsset(struct wcsprm *wcs)
  
-@@ -2204,12 +2201,12 @@ int wcsset(struct wcsprm *wcs)
+ {
+   static const char *function = "wcsset";
+ 
+-  char   dpq[16], scode[4], stype[5];
+-  int    i, j, k, m, n, naxis, ndpmax, status;
+-  double lambda, rho;
+-  double *cd, *pc;
+-  struct disprm *dis;
+-  struct dpkey  *keyp;
+-  struct linprm *wcslin = &(wcs->lin);
+-  struct celprm *wcscel = &(wcs->cel);
+-  struct prjprm *wcsprj = &(wcscel->prj);
+-  struct spcprm *wcsspc = &(wcs->spc);
+-  struct wcserr **err;
+-
+-
    if (wcs == 0x0) return WCSERR_NULL_POINTER;
-   err = &(wcs->err);
+-  err = &(wcs->err);
++  struct wcserr **err = &(wcs->err);
  
 -  /* Determine axis types from CTYPEia. */
 +  // Determine axis types from CTYPEia.
++  int status;
    if ((status = wcs_types(wcs))) {
      return status;
    }
@@ -24213,13 +27475,19 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if ((status = wcs_units(wcs))) {
      return status;
    }
-@@ -2221,45 +2218,45 @@ int wcsset(struct wcsprm *wcs)
+ 
+-  naxis = wcs->naxis;
++  int naxis = wcs->naxis;
+   if (32 < naxis) {
+     return wcserr_set(WCSERR_SET(WCSERR_BAD_PARAM),
+       "naxis must not exceed 32 (got %d)", naxis);
    }
  
  
 -  /* Non-linear celestial axes present? */
 +  // Non-linear celestial axes present?
    if (wcs->lng >= 0 && wcs->types[wcs->lng] == 2200) {
++    struct celprm *wcscel = &(wcs->cel);
      celini(wcscel);
  
 -    /* CRVALia, LONPOLEa, and LATPOLEa keyvalues. */
@@ -24231,20 +27499,25 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
 -    /* Do alias translation for TPU/TPV before dealing with PVi_ma. */
 +    // Do alias translation for TPU/TPV before dealing with PVi_ma.
++    struct prjprm *wcsprj = &(wcscel->prj);
      strncpy(wcsprj->code, wcs->ctype[wcs->lng]+5, 3);
      wcsprj->code[3] = '\0';
      if (strncmp(wcsprj->code, "TPU", 3) == 0 ||
          strncmp(wcsprj->code, "TPV", 3) == 0) {
 -      /* Translate the PV parameters. */
 +      // Translate the PV parameters.
++      struct disprm *dis;
        if ((dis = calloc(1, sizeof(struct disprm))) == 0x0) {
          return wcserr_set(WCS_ERRMSG(WCSERR_MEMORY));
        }
  
-       ndpmax = 6 + wcs->npv;
+-      ndpmax = 6 + wcs->npv;
++      int ndpmax = 6 + wcs->npv;
  
 -      /* Attach it to linprm.  Also inits it. */
 +      // Attach it to linprm.  Also inits it.
++      char dpq[16];
++      struct linprm *wcslin = &(wcs->lin);
        dis->flag = -1;
        if (strncmp(wcsprj->code, "TPU", 3) == 0) {
 -        /* Prior distortion. */
@@ -24264,20 +27537,23 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        strcpy(dis->dtype[wcs->lat], "TPV");
  
 -      /* Keep the keywords in axis-order to aid debugging. */
+-      keyp = dis->dp;
 +      // Keep the keywords in axis-order to aid debugging.
-       keyp = dis->dp;
++      struct dpkey *keyp = dis->dp;
        dis->ndp = 0;
  
-@@ -2269,7 +2266,7 @@ int wcsset(struct wcsprm *wcs)
+       sprintf(dpq+2, "%d", wcs->lng+1);
+@@ -2269,32 +2498,32 @@ int wcsset(struct wcsprm *wcs)
        dpfill(keyp++, dpq, "AXIS.2", 0, 0, 2, 0.0);
        dis->ndp += 3;
  
 -      /* Copy distortion parameters for the longitude axis. */
+-      for (k = 0; k < wcs->npv; k++) {
 +      // Copy distortion parameters for the longitude axis.
-       for (k = 0; k < wcs->npv; k++) {
++      for (int k = 0; k < wcs->npv; k++) {
          if (wcs->pv[k].i != wcs->lng+1) continue;
          sprintf(keyp->field, "%s.TPV.%d", dpq, wcs->pv[k].m);
-@@ -2277,7 +2274,7 @@ int wcsset(struct wcsprm *wcs)
+         dpfill(keyp++, 0x0, 0x0, 0, 1, 0, wcs->pv[k].value);
          dis->ndp++;
        }
  
@@ -24286,16 +27562,29 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        sprintf(dpq+2, "%d", wcs->lat+1);
        dpfill(keyp++, dpq, "NAXES",  0, 0, 2, 0.0);
        dpfill(keyp++, dpq, "AXIS.1", 0, 0, 2, 0.0);
-@@ -2291,7 +2288,7 @@ int wcsset(struct wcsprm *wcs)
+       dpfill(keyp++, dpq, "AXIS.2", 0, 0, 1, 0.0);
+       dis->ndp += 3;
+ 
+-      for (k = 0; k < wcs->npv; k++) {
++      for (int k = 0; k < wcs->npv; k++) {
+         if (wcs->pv[k].i != wcs->lat+1) continue;
+         sprintf(keyp->field, "%s.TPV.%d", dpq, wcs->pv[k].m);
+         dpfill(keyp++, 0x0, 0x0, 0, 1, 0, wcs->pv[k].value);
          dis->ndp++;
        }
  
 -      /* Erase PVi_ma associated with the celestial axes. */
+-      n = 0;
+-      for (k = 0; k < wcs->npv; k++) {
+-        i = wcs->pv[k].i - 1;
 +      // Erase PVi_ma associated with the celestial axes.
-       n = 0;
-       for (k = 0; k < wcs->npv; k++) {
-         i = wcs->pv[k].i - 1;
-@@ -2307,28 +2304,28 @@ int wcsset(struct wcsprm *wcs)
++      int n = 0;
++      for (int k = 0; k < wcs->npv; k++) {
++        int i = wcs->pv[k].i - 1;
+         if (i == wcs->lng || i == wcs->lat) continue;
+ 
+         wcs->pv[n].i = wcs->pv[k].i;
+@@ -2307,42 +2536,42 @@ int wcsset(struct wcsprm *wcs)
        wcs->npv = n;
        strcpy(wcsprj->code, "TAN");
  
@@ -24322,16 +27611,19 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
      }
  
 -    /* PVi_ma keyvalues. */
+-    for (k = 0; k < wcs->npv; k++) {
 +    // PVi_ma keyvalues.
-     for (k = 0; k < wcs->npv; k++) {
++    for (int k = 0; k < wcs->npv; k++) {
        if (wcs->pv[k].i == 0) {
 -        /* From a PROJPn keyword. */
 +        // From a PROJPn keyword.
          wcs->pv[k].i = wcs->lat + 1;
        }
  
-@@ -2336,13 +2333,13 @@ int wcsset(struct wcsprm *wcs)
-       m = wcs->pv[k].m;
+-      i = wcs->pv[k].i - 1;
+-      m = wcs->pv[k].m;
++      int i = wcs->pv[k].i - 1;
++      int m = wcs->pv[k].m;
  
        if (i == wcs->lat) {
 -        /* PVi_ma associated with latitude axis. */
@@ -24346,7 +27638,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          switch (m) {
          case 0:
            wcscel->offset = (wcs->pv[k].value != 0.0);
-@@ -2354,11 +2351,11 @@ int wcsset(struct wcsprm *wcs)
+@@ -2354,11 +2583,11 @@ int wcsset(struct wcsprm *wcs)
            wcscel->theta0 = wcs->pv[k].value;
            break;
          case 3:
@@ -24360,7 +27652,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
            wcscel->ref[3] = wcs->pv[k].value;
            break;
          default:
-@@ -2370,7 +2367,7 @@ int wcsset(struct wcsprm *wcs)
+@@ -2370,7 +2599,7 @@ int wcsset(struct wcsprm *wcs)
        }
      }
  
@@ -24369,7 +27661,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
      if (strncmp(wcs->ctype[wcs->lng]+5, "GLS", 3) == 0) {
        wcscel->offset = 1;
        wcscel->phi0   = 0.0;
-@@ -2378,7 +2375,7 @@ int wcsset(struct wcsprm *wcs)
+@@ -2378,7 +2607,7 @@ int wcsset(struct wcsprm *wcs)
        strcpy(wcsprj->code, "SFL");
  
      } else if (strncmp(wcs->ctype[wcs->lng]+5, "NCP", 3) == 0) {
@@ -24378,7 +27670,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        if (wcscel->ref[1] == 0.0) {
          return wcserr_set(WCSERR_SET(WCSERR_BAD_PARAM),
            "Invalid projection: NCP blows up on the equator");
-@@ -2389,13 +2386,13 @@ int wcsset(struct wcsprm *wcs)
+@@ -2389,19 +2618,19 @@ int wcsset(struct wcsprm *wcs)
        wcsprj->pv[2] = cosd(wcscel->ref[1])/sind(wcscel->ref[1]);
      }
  
@@ -24394,16 +27686,28 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
      wcs->lonpole = wcscel->ref[2];
      wcs->latpole = wcscel->ref[3];
  
-@@ -2423,7 +2420,7 @@ int wcsset(struct wcsprm *wcs)
+-    for (k = 0; k < wcs->npv; k++) {
+-      i = wcs->pv[k].i - 1;
+-      m = wcs->pv[k].m;
++    for (int k = 0; k < wcs->npv; k++) {
++      int i = wcs->pv[k].i - 1;
++      int m = wcs->pv[k].m;
+ 
+       if (i == wcs->lng) {
+         switch (m) {
+@@ -2423,8 +2652,10 @@ int wcsset(struct wcsprm *wcs)
    }
  
  
 -  /* Non-linear spectral axis present? */
 +  // Non-linear spectral axis present?
    if (wcs->spec >= 0 && wcs->types[wcs->spec] == 3300) {
++    char scode[4], stype[5];
++    struct spcprm *wcsspc = &(wcs->spc);
      spcini(wcsspc);
      if ((status = spctype(wcs->ctype[wcs->spec], stype, scode, 0x0, 0x0, 0x0,
-@@ -2433,32 +2430,32 @@ int wcsset(struct wcsprm *wcs)
+                           0x0, 0x0, err))) {
+@@ -2433,64 +2664,65 @@ int wcsset(struct wcsprm *wcs)
      strcpy(wcsspc->type, stype);
      strcpy(wcsspc->code, scode);
  
@@ -24414,10 +27718,13 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
      wcsspc->restwav = wcs->restwav;
  
 -    /* PVi_ma keyvalues. */
+-    for (k = 0; k < wcs->npv; k++) {
+-      i = wcs->pv[k].i - 1;
+-      m = wcs->pv[k].m;
 +    // PVi_ma keyvalues.
-     for (k = 0; k < wcs->npv; k++) {
-       i = wcs->pv[k].i - 1;
-       m = wcs->pv[k].m;
++    for (int k = 0; k < wcs->npv; k++) {
++      int i = wcs->pv[k].i - 1;
++      int m = wcs->pv[k].m;
  
        if (i == wcs->spec) {
 -        /* PVi_ma associated with grism axis. */
@@ -24437,36 +27744,57 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
  
 -  /* Tabular axes present? */
+-  for (j = 0; j < wcs->ntab; j++) {
+-    if ((status = tabset(wcs->tab + j))) {
 +  // Tabular axes present?
-   for (j = 0; j < wcs->ntab; j++) {
-     if ((status = tabset(wcs->tab + j))) {
++  for (int itab = 0; itab < wcs->ntab; itab++) {
++    if ((status = tabset(wcs->tab + itab))) {
        return wcserr_set(WCS_ERRMSG(wcs_taberr[status]));
-@@ -2466,13 +2463,13 @@ int wcsset(struct wcsprm *wcs)
+     }
    }
  
  
 -  /* Initialize the linear transformation. */
+-  wcs->altlin &= 7;
 +  // Initialize the linear transformation.
-   wcs->altlin &= 7;
++  wcs->altlin &= 15;
    if (wcs->altlin > 1 && !(wcs->altlin & 1)) {
-     pc = wcs->pc;
+-    pc = wcs->pc;
++    double *pc = wcs->pc;
  
-     if (wcs->altlin & 2) {
+-    if (wcs->altlin & 2) {
 -      /* Copy CDi_ja to PCi_ja and reset CDELTia. */
+-      cd = wcs->cd;
+-      for (i = 0; i < naxis; i++) {
+-        for (j = 0; j < naxis; j++) {
++    if ((wcs->altlin & 2) && !(wcs->altlin & 8)) {
 +      // Copy CDi_ja to PCi_ja and reset CDELTia.
-       cd = wcs->cd;
-       for (i = 0; i < naxis; i++) {
-         for (j = 0; j < naxis; j++) {
-@@ -2482,7 +2479,7 @@ int wcsset(struct wcsprm *wcs)
++      double *cd = wcs->cd;
++      for (int i = 0; i < naxis; i++) {
++        for (int j = 0; j < naxis; j++) {
+           *(pc++) = *(cd++);
+         }
+         wcs->cdelt[i] = 1.0;
        }
  
      } else if (wcs->altlin & 4) {
 -      /* Construct PCi_ja from CROTAia. */
 +      // Construct PCi_ja from CROTAia.
++      int i, j;
        if ((i = wcs->lng) >= 0 && (j = wcs->lat) >= 0) {
-         rho = wcs->crota[j];
+-        rho = wcs->crota[j];
++        double rho = wcs->crota[j];
  
-@@ -2508,7 +2505,7 @@ int wcsset(struct wcsprm *wcs)
+         if (wcs->cdelt[i] == 0.0) {
+           return wcserr_set(WCSERR_SET(WCSERR_SINGULAR_MTX),
+             "Singular transformation matrix, CDELT%d is zero", i+1);
+         }
+-        lambda = wcs->cdelt[j]/wcs->cdelt[i];
++        double lambda = wcs->cdelt[j]/wcs->cdelt[i];
+ 
+         *(pc + i*naxis + i) = *(pc + j*naxis + j) = cosd(rho);
+         *(pc + i*naxis + j) = *(pc + j*naxis + i) = sind(rho);
+@@ -2508,7 +2740,7 @@ int wcsset(struct wcsprm *wcs)
    }
  
  
@@ -24475,7 +27803,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if (strcmp(wcs->lngtyp, "RA")   == 0 ||
        strcmp(wcs->lngtyp, "ELON") == 0 ||
        strcmp(wcs->lngtyp, "HLON") == 0) {
-@@ -2523,7 +2520,7 @@ int wcsset(struct wcsprm *wcs)
+@@ -2523,7 +2755,7 @@ int wcsset(struct wcsprm *wcs)
  
      } else if (strcmp(wcs->radesys, "ICRS")  == 0 ||
                 strcmp(wcs->radesys, "GAPPT") == 0) {
@@ -24484,7 +27812,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        wcs->equinox = UNDEFINED;
  
      } else if (undefined(wcs->equinox)) {
-@@ -2536,13 +2533,13 @@ int wcsset(struct wcsprm *wcs)
+@@ -2536,17 +2768,17 @@ int wcsset(struct wcsprm *wcs)
      }
  
    } else {
@@ -24500,7 +27828,12 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if (wcs->alt[0] == '\0') wcs->alt[0] = ' ';
    memset(wcs->alt+1, '\0', 3);
  
-@@ -2566,7 +2563,7 @@ int wcsset(struct wcsprm *wcs)
+-  for (i = 0; i < naxis; i++) {
++  for (int i = 0; i < naxis; i++) {
+     wcsutil_null_fill(72, wcs->cname[i]);
+   }
+   wcsutil_null_fill(72, wcs->wcsname);
+@@ -2566,7 +2798,7 @@ int wcsset(struct wcsprm *wcs)
    wcsutil_null_fill(72, wcs->ssysobs);
    wcsutil_null_fill(72, wcs->ssyssrc);
  
@@ -24509,8 +27842,12 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if (wcs->dateref[0] == '\0') {
      if (undefined(wcs->mjdref[0])) {
        wcs->mjdref[0] = 0.0;
-@@ -2581,7 +2578,7 @@ int wcsset(struct wcsprm *wcs)
-   return 0;
+@@ -2578,10 +2810,10 @@ int wcsset(struct wcsprm *wcs)
+ 
+   wcs->flag = WCSSET;
+ 
+-  return 0;
++  return WCSERR_SUCCESS;
  }
  
 -/* : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : :  */
@@ -24518,16 +27855,22 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
  int wcs_types(struct wcsprm *wcs)
  
-@@ -2599,7 +2596,7 @@ int wcs_types(struct wcsprm *wcs)
+@@ -2594,12 +2826,11 @@ int wcs_types(struct wcsprm *wcs)
+   const char *alt = "";
+   char ctypei[16], pcode[4], requir[16], scode[4], specsys[9];
+   int i, j, m, naxis, *ndx = 0x0, type;
+-  struct wcserr **err;
+ 
    if (wcs == 0x0) return WCSERR_NULL_POINTER;
-   err = &(wcs->err);
+-  err = &(wcs->err);
++  struct wcserr **err = &(wcs->err);
  
 -  /* Parse the CTYPEia keyvalues. */
 +  // Parse the CTYPEia keyvalues.
    pcode[0]  = '\0';
    requir[0] = '\0';
    wcs->lng  = -1;
-@@ -2617,63 +2614,63 @@ int wcs_types(struct wcsprm *wcs)
+@@ -2617,63 +2848,63 @@ int wcs_types(struct wcsprm *wcs)
    }
  
    for (i = 0; i < naxis; i++) {
@@ -24605,7 +27948,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->types[i] += 2000;
          if (wcs->lng < 0) {
            wcs->lng = i;
-@@ -2683,7 +2680,7 @@ int wcs_types(struct wcsprm *wcs)
+@@ -2683,7 +2914,7 @@ int wcs_types(struct wcsprm *wcs)
        } else if (strcmp(ctypei,   "DEC") == 0 ||
                   strcmp(ctypei+1, "LAT") == 0 ||
                   strcmp(ctypei+2, "LT")  == 0) {
@@ -24614,7 +27957,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->types[i] += 2001;
          if (wcs->lat < 0) {
            wcs->lat = i;
-@@ -2691,19 +2688,19 @@ int wcs_types(struct wcsprm *wcs)
+@@ -2691,19 +2922,19 @@ int wcs_types(struct wcsprm *wcs)
          }
  
        } else if (strcmp(ctypei, "CUBEFACE") == 0) {
@@ -24637,7 +27980,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          if (wcs->spec < 0) wcs->spec = i;
          wcs->types[i] += 3000;
        }
-@@ -2712,12 +2709,12 @@ int wcs_types(struct wcsprm *wcs)
+@@ -2712,12 +2943,12 @@ int wcs_types(struct wcsprm *wcs)
      }
  
  
@@ -24653,7 +27996,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        if (wcs->spec >= 0) {
          return wcserr_set(WCSERR_SET(WCSERR_BAD_CTYPE),
            "Multiple spectral axes (in CTYPE%d%.1s and CTYPE%d%.1s)",
-@@ -2730,19 +2727,19 @@ int wcs_types(struct wcsprm *wcs)
+@@ -2730,19 +2961,19 @@ int wcs_types(struct wcsprm *wcs)
      }
  
  
@@ -24676,7 +28019,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->types[i] = -1;
          return wcserr_set(WCSERR_SET(WCSERR_BAD_CTYPE),
            "Unrecognized projection code (%s in CTYPE%d%.1s)",
-@@ -2750,10 +2747,10 @@ int wcs_types(struct wcsprm *wcs)
+@@ -2750,10 +2981,10 @@ int wcs_types(struct wcsprm *wcs)
        }
      }
  
@@ -24689,7 +28032,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        sprintf(pcode, "%.3s", ctypei+5);
  
        if (strncmp(ctypei, "RA--", 4) == 0) {
-@@ -2793,7 +2790,7 @@ int wcs_types(struct wcsprm *wcs)
+@@ -2793,7 +3024,7 @@ int wcs_types(struct wcsprm *wcs)
          ndx = &wcs->lng;
          sprintf(requir, "%s-%s", wcs->lngtyp, pcode);
        } else {
@@ -24698,7 +28041,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->types[i] = -1;
  
          wcs->lng = -1;
-@@ -2806,11 +2803,11 @@ int wcs_types(struct wcsprm *wcs)
+@@ -2806,11 +3037,11 @@ int wcs_types(struct wcsprm *wcs)
        if (wcs->lat >= 0) wcs->types[i]++;
  
      } else {
@@ -24712,7 +28055,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          wcs->lng = -1;
          wcs->lat = -1;
          return wcserr_set(WCSERR_SET(WCSERR_BAD_CTYPE), "Inconsistent "
-@@ -2823,19 +2820,19 @@ int wcs_types(struct wcsprm *wcs)
+@@ -2823,19 +3054,19 @@ int wcs_types(struct wcsprm *wcs)
      }
    }
  
@@ -24736,8 +28079,12 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        i = wcs->tab[j].map[m];
  
        type = (wcs->types[i] / 100) % 10;
-@@ -2850,7 +2847,7 @@ int wcs_types(struct wcsprm *wcs)
-   return 0;
+@@ -2847,10 +3078,10 @@ int wcs_types(struct wcsprm *wcs)
+     }
+   }
+ 
+-  return 0;
++  return WCSERR_SUCCESS;
  }
  
 -/* : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : :  */
@@ -24745,11 +28092,14 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
  int wcs_units(struct wcsprm *wcs)
  
-@@ -2867,15 +2864,15 @@ int wcs_units(struct wcsprm *wcs)
+@@ -2867,15 +3098,18 @@ int wcs_units(struct wcsprm *wcs)
  
    naxis = wcs->naxis;
    for (i = 0; i < naxis; i++) {
 -    /* Use types set by wcs_types(). */
++    // Squeeze out trailing blanks.
++    wcsutil_null_fill(72, wcs->cunit[i]);
++
 +    // Use types set by wcs_types().
      switch (wcs->types[i]/1000) {
      case 2:
@@ -24764,7 +28114,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        strncpy(ctype, wcs->ctype[i], 8);
        ctype[8] = '\0';
        spctyp(ctype, 0x0, 0x0, 0x0, units, 0x0, 0x0, 0x0);
-@@ -2885,7 +2882,7 @@ int wcs_units(struct wcsprm *wcs)
+@@ -2885,18 +3119,20 @@ int wcs_units(struct wcsprm *wcs)
        continue;
      }
  
@@ -24773,7 +28123,8 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
      if ((wcs->types[i]/100)%10 == 5) {
        continue;
      }
-@@ -2894,9 +2891,12 @@ int wcs_units(struct wcsprm *wcs)
+ 
+-    wcsutil_null_fill(72, wcs->cunit[i]);
      if (wcs->cunit[i][0]) {
        if (wcsunitse(wcs->cunit[i], units, &scale, &offset, &power,
                      &uniterr)) {
@@ -24789,8 +28140,12 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          return WCSERR_BAD_COORD_TRANS;
        }
  
-@@ -2919,7 +2919,7 @@ int wcs_units(struct wcsprm *wcs)
-   return 0;
+@@ -2916,10 +3152,10 @@ int wcs_units(struct wcsprm *wcs)
+     }
+   }
+ 
+-  return 0;
++  return WCSERR_SUCCESS;
  }
  
 -/*--------------------------------------------------------------------------*/
@@ -24798,7 +28153,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
  int wcsp2s(
    struct wcsprm *wcs,
-@@ -2943,7 +2943,7 @@ int wcsp2s(
+@@ -2943,7 +3179,7 @@ int wcsp2s(
    struct prjprm *wcsprj = &(wcscel->prj);
    struct wcserr **err;
  
@@ -24807,7 +28162,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if (wcs == 0x0) return WCSERR_NULL_POINTER;
    err = &(wcs->err);
  
-@@ -2951,19 +2951,19 @@ int wcsp2s(
+@@ -2951,19 +3187,19 @@ int wcsp2s(
      if ((status = wcsset(wcs))) return status;
    }
  
@@ -24830,7 +28185,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if ((istatp = calloc(ncoord, sizeof(int))) == 0x0) {
      return wcserr_set(WCS_ERRMSG(WCSERR_MEMORY));
    }
-@@ -2972,13 +2972,13 @@ int wcsp2s(
+@@ -2972,13 +3208,13 @@ int wcsp2s(
    wcsutil_setAli(ncoord, 1, stat);
  
  
@@ -24847,7 +28202,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        img = imgcrd + i;
        wrl = world  + i;
        crvali = wcs->crval[i];
-@@ -2989,16 +2989,16 @@ int wcsp2s(
+@@ -2989,16 +3225,16 @@ int wcsp2s(
        }
  
      } else if (wcs->types[i] == 2200) {
@@ -24867,7 +28222,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          img = imgcrd;
          statp = stat;
          bits = (1 << i) | (1 << wcs->lat);
-@@ -3039,7 +3039,7 @@ int wcsp2s(
+@@ -3039,7 +3275,7 @@ int wcsp2s(
          }
        }
  
@@ -24876,7 +28231,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        nx = ncoord;
        ny = 0;
  
-@@ -3051,7 +3051,7 @@ int wcsp2s(
+@@ -3051,7 +3287,7 @@ int wcsp2s(
          ny = 1;
        }
  
@@ -24885,7 +28240,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        if ((istat = celx2s(wcscel, nx, ny, nelem, nelem, imgcrd+i,
                            imgcrd+wcs->lat, phi, theta, world+i,
                            world+wcs->lat, istatp))) {
-@@ -3063,7 +3063,7 @@ int wcsp2s(
+@@ -3063,7 +3299,7 @@ int wcsp2s(
          }
        }
  
@@ -24894,7 +28249,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        if (iso_x && iso_y) {
          wcsutil_setAll(ncoord, nelem, world+i);
          wcsutil_setAll(ncoord, nelem, world+wcs->lat);
-@@ -3078,7 +3078,7 @@ int wcsp2s(
+@@ -3078,7 +3314,7 @@ int wcsp2s(
        }
  
      } else if (type == 3 || type == 4) {
@@ -24903,7 +28258,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        nx = ncoord;
        if ((iso_x = wcsutil_allEq(ncoord, nelem, imgcrd+i))) {
          nx = 1;
-@@ -3086,7 +3086,7 @@ int wcsp2s(
+@@ -3086,7 +3322,7 @@ int wcsp2s(
  
        istat = 0;
        if (wcs->types[i] == 3300) {
@@ -24912,7 +28267,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          istat = spcx2s(&(wcs->spc), nx, nelem, nelem, imgcrd+i, world+i,
                         istatp);
          if (istat) {
-@@ -3096,7 +3096,7 @@ int wcsp2s(
+@@ -3096,7 +3332,7 @@ int wcsp2s(
            }
          }
        } else if (type == 4) {
@@ -24921,7 +28276,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          istat = logx2s(wcs->crval[i], nx, nelem, nelem, imgcrd+i, world+i,
                         istatp);
          if (istat) {
-@@ -3107,7 +3107,7 @@ int wcsp2s(
+@@ -3107,7 +3343,7 @@ int wcsp2s(
          }
        }
  
@@ -24930,7 +28285,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        if (iso_x) {
          wcsutil_setAll(ncoord, nelem, world+i);
          wcsutil_setAli(ncoord, 1, istatp);
-@@ -3120,7 +3120,7 @@ int wcsp2s(
+@@ -3120,7 +3356,7 @@ int wcsp2s(
    }
  
  
@@ -24939,7 +28294,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    for (itab = 0; itab < wcs->ntab; itab++) {
      istat = tabx2s(wcs->tab + itab, ncoord, nelem, imgcrd, world, istatp);
  
-@@ -3141,7 +3141,7 @@ int wcsp2s(
+@@ -3141,7 +3377,7 @@ int wcsp2s(
    }
  
  
@@ -24948,7 +28303,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    for (i = wcs->naxis; i < nelem; i++) {
      world[i] = 0.0;
      wcsutil_setAll(ncoord, nelem, world+i);
-@@ -3152,7 +3152,7 @@ cleanup:
+@@ -3152,7 +3388,7 @@ cleanup:
    return status;
  }
  
@@ -24957,7 +28312,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
  int wcss2p(
    struct wcsprm* wcs,
-@@ -3178,7 +3178,7 @@ int wcss2p(
+@@ -3178,7 +3414,7 @@ int wcss2p(
    struct wcserr **err;
  
  
@@ -24966,7 +28321,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if (wcs == 0x0) return WCSERR_NULL_POINTER;
    err = &(wcs->err);
  
-@@ -3186,13 +3186,13 @@ int wcss2p(
+@@ -3186,13 +3422,13 @@ int wcss2p(
      if ((status = wcsset(wcs))) return status;
    }
  
@@ -24982,7 +28337,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if ((istatp = calloc(ncoord, sizeof(int))) == 0x0) {
      return wcserr_set(WCS_ERRMSG(WCSERR_MEMORY));
    }
-@@ -3202,13 +3202,13 @@ int wcss2p(
+@@ -3202,13 +3438,13 @@ int wcss2p(
    wcsutil_setAli(ncoord, 1, stat);
  
  
@@ -24999,7 +28354,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        wrl = world  + i;
        img = imgcrd + i;
        crvali = wcs->crval[i];
-@@ -3219,7 +3219,7 @@ int wcss2p(
+@@ -3219,7 +3455,7 @@ int wcss2p(
        }
  
      } else if (wcs->types[i] == 2200) {
@@ -25008,7 +28363,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        nlng = ncoord;
        nlat = 0;
  
-@@ -3231,7 +3231,7 @@ int wcss2p(
+@@ -3231,7 +3467,7 @@ int wcss2p(
          nlat = 1;
        }
  
@@ -25017,7 +28372,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        if ((istat = cels2x(wcscel, nlng, nlat, nelem, nelem, world+i,
                            world+wcs->lat, phi, theta, imgcrd+i,
                            imgcrd+wcs->lat, istatp))) {
-@@ -3243,7 +3243,7 @@ int wcss2p(
+@@ -3243,7 +3479,7 @@ int wcss2p(
          }
        }
  
@@ -25026,7 +28381,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        if (isolng && isolat) {
          wcsutil_setAll(ncoord, nelem, imgcrd+i);
          wcsutil_setAll(ncoord, nelem, imgcrd+wcs->lat);
-@@ -3257,16 +3257,16 @@ int wcss2p(
+@@ -3257,16 +3493,16 @@ int wcss2p(
          wcsutil_setBit(ncoord, istatp, bits, stat);
        }
  
@@ -25046,7 +28401,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          img = imgcrd;
          for (k = 0; k < ncoord; k++) {
            if (*(img+wcs->lat) < -0.5*offset) {
-@@ -3293,7 +3293,7 @@ int wcss2p(
+@@ -3293,7 +3529,7 @@ int wcss2p(
        }
  
      } else if (type == 3 || type == 4) {
@@ -25055,7 +28410,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        nwrld = ncoord;
        if ((isospec = wcsutil_allEq(ncoord, nelem, world+i))) {
          nwrld = 1;
-@@ -3301,7 +3301,7 @@ int wcss2p(
+@@ -3301,7 +3537,7 @@ int wcss2p(
  
        istat = 0;
        if (wcs->types[i] == 3300) {
@@ -25064,7 +28419,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          istat = spcs2x(&(wcs->spc), nwrld, nelem, nelem, world+i,
                         imgcrd+i, istatp);
          if (istat) {
-@@ -3311,7 +3311,7 @@ int wcss2p(
+@@ -3311,7 +3547,7 @@ int wcss2p(
            }
          }
        } else if (type == 4) {
@@ -25073,7 +28428,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          istat = logs2x(wcs->crval[i], nwrld, nelem, nelem, world+i,
                         imgcrd+i, istatp);
          if (istat) {
-@@ -3322,7 +3322,7 @@ int wcss2p(
+@@ -3322,7 +3558,7 @@ int wcss2p(
          }
        }
  
@@ -25082,7 +28437,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        if (isospec) {
          wcsutil_setAll(ncoord, nelem, imgcrd+i);
          wcsutil_setAli(ncoord, 1, istatp);
-@@ -3335,7 +3335,7 @@ int wcss2p(
+@@ -3335,7 +3571,7 @@ int wcss2p(
    }
  
  
@@ -25091,7 +28446,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    for (itab = 0; itab < wcs->ntab; itab++) {
      istat = tabs2x(wcs->tab + itab, ncoord, nelem, world, imgcrd, istatp);
  
-@@ -3356,14 +3356,14 @@ int wcss2p(
+@@ -3356,14 +3592,14 @@ int wcss2p(
    }
  
  
@@ -25108,7 +28463,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if ((istat = linx2p(&(wcs->lin), ncoord, nelem, imgcrd, pixcrd))) {
      status = wcserr_set(WCS_ERRMSG(wcs_linerr[istat]));
      goto cleanup;
-@@ -3374,7 +3374,7 @@ cleanup:
+@@ -3374,7 +3610,7 @@ cleanup:
    return status;
  }
  
@@ -25117,7 +28472,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
  int wcsmix(
    struct wcsprm *wcs,
-@@ -3408,7 +3408,7 @@ int wcsmix(
+@@ -3408,7 +3644,7 @@ int wcsmix(
    struct wcsprm wcs0;
    struct wcserr **err;
  
@@ -25126,7 +28481,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    if (wcs == 0x0) return WCSERR_NULL_POINTER;
    err = &(wcs->err);
  
-@@ -3420,24 +3420,24 @@ int wcsmix(
+@@ -3416,28 +3652,33 @@ int wcsmix(
+     if ((status = wcsset(wcs))) return status;
+   }
+ 
++  if (wcs->lng < 0 || wcs->lat < 0) {
++    return wcserr_set(WCSERR_SET(WCSERR_BAD_SUBIMAGE),
++      "Image does not have celestial axes");
++  }
++
+   worldlng = world + wcs->lng;
    worldlat = world + wcs->lat;
  
  
@@ -25155,7 +28519,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    nstep = viter;
    if (nstep < 5) {
      nstep = 5;
-@@ -3445,18 +3445,18 @@ int wcsmix(
+@@ -3445,18 +3686,18 @@ int wcsmix(
      nstep = 10;
    }
  
@@ -25179,7 +28543,22 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        lat0 = span[0];
        *worldlat = lat0;
        if ((status = wcss2p(wcs, 1, 0, world, phi, theta, imgcrd, pixcrd,
-@@ -3488,7 +3488,7 @@ int wcsmix(
+@@ -3469,7 +3710,7 @@ int wcsmix(
+       d0 = pixcrd[mixpix] - pixmix;
+ 
+       dabs = fabs(d0);
+-      if (dabs < tol) return 0;
++      if (dabs < tol) return WCSERR_SUCCESS;
+ 
+       lat1 = span[1];
+       *worldlat = lat1;
+@@ -3483,12 +3724,12 @@ int wcsmix(
+       d1 = pixcrd[mixpix] - pixmix;
+ 
+       dabs = fabs(d1);
+-      if (dabs < tol) return 0;
++      if (dabs < tol) return WCSERR_SUCCESS;
+ 
        lmin = lat1;
        dmin = dabs;
  
@@ -25188,7 +28567,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        if (signbit(d0) != signbit(d1)) {
          crossed = 1;
          dx = d1;
-@@ -3498,7 +3498,7 @@ int wcsmix(
+@@ -3498,7 +3739,7 @@ int wcsmix(
        }
  
        for (retry = 0; retry < 4; retry++) {
@@ -25197,14 +28576,15 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          while (lat0 > span[0]) {
            lat0 -= step;
            if (lat0 < span[0]) lat0 = span[0];
-@@ -3512,32 +3512,32 @@ int wcsmix(
+@@ -3512,32 +3753,32 @@ int wcsmix(
            }
            d0 = pixcrd[mixpix] - pixmix;
  
 -          /* Check for a solution. */
 +          // Check for a solution.
            dabs = fabs(d0);
-           if (dabs < tol) return 0;
+-          if (dabs < tol) return 0;
++          if (dabs < tol) return WCSERR_SUCCESS;
  
 -          /* Record the point of closest approach. */
 +          // Record the point of closest approach.
@@ -25236,7 +28616,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
              lambda = d0/(d0-d1);
              if (lambda < 0.1) {
                lambda = 0.1;
-@@ -3556,20 +3556,20 @@ int wcsmix(
+@@ -3556,20 +3797,20 @@ int wcsmix(
                return status;
              }
  
@@ -25244,12 +28624,14 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
 +            // Check for a solution.
              d = pixcrd[mixpix] - pixmix;
              dabs = fabs(d);
-             if (dabs < tol) return 0;
+-            if (dabs < tol) return 0;
++            if (dabs < tol) return WCSERR_SUCCESS;
  
              if (dlat < tol) {
 -              /* An artifact of numerical imprecision. */
+-              if (dabs < tol2) return 0;
 +              // An artifact of numerical imprecision.
-               if (dabs < tol2) return 0;
++              if (dabs < tol2) return WCSERR_SUCCESS;
  
 -              /* Must be a discontinuity. */
 +              // Must be a discontinuity.
@@ -25261,7 +28643,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
              if (dabs < dmin) {
                lmin = lat;
                dmin = dabs;
-@@ -3584,14 +3584,14 @@ int wcsmix(
+@@ -3584,14 +3825,14 @@ int wcsmix(
              }
            }
  
@@ -25278,7 +28660,25 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
            if (lmin == span[0]) break;
            if (lmin == span[1]) break;
  
-@@ -3671,9 +3671,9 @@ int wcsmix(
+@@ -3635,7 +3876,7 @@ int wcsmix(
+             }
+             d0m = fabs(pixcrd[mixpix] - pixmix);
+ 
+-            if (d0m < tol) return 0;
++            if (d0m < tol) return WCSERR_SUCCESS;
+ 
+             lat1m = (lat1 + lat)/2.0;
+             *worldlat = lat1m;
+@@ -3648,7 +3889,7 @@ int wcsmix(
+             }
+             d1m = fabs(pixcrd[mixpix] - pixmix);
+ 
+-            if (d1m < tol) return 0;
++            if (d1m < tol) return WCSERR_SUCCESS;
+ 
+             if (d0m < d && d0m <= d1m) {
+               lat1 = lat;
+@@ -3671,9 +3912,9 @@ int wcsmix(
        }
  
      } else {
@@ -25290,7 +28690,21 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        lng0 = span[0];
        *worldlng = lng0;
        if ((status = wcss2p(wcs, 1, 0, world, phi, theta, imgcrd, pixcrd,
-@@ -3704,7 +3704,7 @@ int wcsmix(
+@@ -3686,7 +3927,7 @@ int wcsmix(
+       d0 = pixcrd[mixpix] - pixmix;
+ 
+       dabs = fabs(d0);
+-      if (dabs < tol) return 0;
++      if (dabs < tol) return WCSERR_SUCCESS;
+ 
+       lng1 = span[1];
+       *worldlng = lng1;
+@@ -3700,11 +3941,11 @@ int wcsmix(
+       d1 = pixcrd[mixpix] - pixmix;
+ 
+       dabs = fabs(d1);
+-      if (dabs < tol) return 0;
++      if (dabs < tol) return WCSERR_SUCCESS;
        lmin = lng1;
        dmin = dabs;
  
@@ -25299,7 +28713,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        if (signbit(d0) != signbit(d1)) {
          crossed = 1;
          dx = d1;
-@@ -3714,7 +3714,7 @@ int wcsmix(
+@@ -3714,7 +3955,7 @@ int wcsmix(
        }
  
        for (retry = 0; retry < 4; retry++) {
@@ -25308,14 +28722,15 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
          while (lng0 > span[0]) {
            lng0 -= step;
            if (lng0 < span[0]) lng0 = span[0];
-@@ -3728,32 +3728,32 @@ int wcsmix(
+@@ -3728,32 +3969,32 @@ int wcsmix(
            }
            d0 = pixcrd[mixpix] - pixmix;
  
 -          /* Check for a solution. */
 +          // Check for a solution.
            dabs = fabs(d0);
-           if (dabs < tol) return 0;
+-          if (dabs < tol) return 0;
++          if (dabs < tol) return WCSERR_SUCCESS;
  
 -          /* Record the point of closest approach. */
 +          // Record the point of closest approach.
@@ -25347,7 +28762,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
              lambda = d0/(d0-d1);
              if (lambda < 0.1) {
                lambda = 0.1;
-@@ -3772,20 +3772,20 @@ int wcsmix(
+@@ -3772,20 +4013,20 @@ int wcsmix(
                return status;
              }
  
@@ -25355,12 +28770,14 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
 +            // Check for a solution.
              d = pixcrd[mixpix] - pixmix;
              dabs = fabs(d);
-             if (dabs < tol) return 0;
+-            if (dabs < tol) return 0;
++            if (dabs < tol) return WCSERR_SUCCESS;
  
              if (dlng < tol) {
 -              /* An artifact of numerical imprecision. */
+-              if (dabs < tol2) return 0;
 +              // An artifact of numerical imprecision.
-               if (dabs < tol2) return 0;
++              if (dabs < tol2) return WCSERR_SUCCESS;
  
 -              /* Must be a discontinuity. */
 +              // Must be a discontinuity.
@@ -25372,7 +28789,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
              if (dabs < dmin) {
                lmin = lng;
                dmin = dabs;
-@@ -3800,14 +3800,14 @@ int wcsmix(
+@@ -3800,14 +4041,14 @@ int wcsmix(
              }
            }
  
@@ -25389,7 +28806,25 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
            if (lmin == span[0]) break;
            if (lmin == span[1]) break;
  
-@@ -3889,7 +3889,7 @@ int wcsmix(
+@@ -3851,7 +4092,7 @@ int wcsmix(
+             }
+             d0m = fabs(pixcrd[mixpix] - pixmix);
+ 
+-            if (d0m < tol) return 0;
++            if (d0m < tol) return WCSERR_SUCCESS;
+ 
+             lng1m = (lng1 + lng)/2.0;
+             *worldlng = lng1m;
+@@ -3864,7 +4105,7 @@ int wcsmix(
+             }
+             d1m = fabs(pixcrd[mixpix] - pixmix);
+ 
+-            if (d1m < tol) return 0;
++            if (d1m < tol) return WCSERR_SUCCESS;
+ 
+             if (d0m < d && d0m <= d1m) {
+               lng1 = lng;
+@@ -3889,7 +4130,7 @@ int wcsmix(
    }
  
  
@@ -25398,7 +28833,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    wcs0 = *wcs;
    wcs0.cel.euler[0] = -90.0;
    wcs0.cel.euler[1] =   0.0;
-@@ -3897,10 +3897,10 @@ int wcsmix(
+@@ -3897,10 +4138,10 @@ int wcsmix(
    wcs0.cel.euler[3] =   1.0;
    wcs0.cel.euler[4] =   0.0;
  
@@ -25411,7 +28846,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
      *phi = 0.0;
      *theta = -*theta;
      sphx2s(wcscel->euler, 1, 1, 1, 1, phi, theta, &lng, &lat);
-@@ -3919,11 +3919,11 @@ int wcsmix(
+@@ -3919,11 +4160,11 @@ int wcsmix(
        *worldlng = lng;
      }
  
@@ -25425,7 +28860,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
      *worldlng = -180.0;
      *worldlat = *theta;
      if ((status = wcss2p(&wcs0, 1, 0, world, phi, theta, imgcrd, pixcrd,
-@@ -3937,15 +3937,15 @@ int wcsmix(
+@@ -3937,15 +4178,15 @@ int wcsmix(
      }
      d0 = pixcrd[mixpix] - pixmix;
  
@@ -25436,7 +28871,8 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
 +      // Recall saved world coordinates.
        *worldlng = lng;
        *worldlat = lat;
-       return 0;
+-      return 0;
++      return WCSERR_SUCCESS;
      }
  
 -    /* Search for a crossing interval. */
@@ -25444,7 +28880,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
      phi0 = -180.0;
      for (k = -179; k <= 180; k++) {
        phi1 = (double) k;
-@@ -3961,16 +3961,16 @@ int wcsmix(
+@@ -3961,16 +4202,16 @@ int wcsmix(
        }
        d1 = pixcrd[mixpix] - pixmix;
  
@@ -25456,7 +28892,8 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
 +        // Recall saved world coordinates.
          *worldlng = lng;
          *worldlat = lat;
-         return 0;
+-        return 0;
++        return WCSERR_SUCCESS;
        }
  
 -      /* Is it a crossing interval? */
@@ -25464,7 +28901,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        if (signbit(d0) != signbit(d1)) break;
  
        phi0 = phi1;
-@@ -3978,7 +3978,7 @@ int wcsmix(
+@@ -3978,7 +4219,7 @@ int wcsmix(
      }
  
      for (iter = 1; iter <= niter; iter++) {
@@ -25473,7 +28910,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        lambda = d0/(d0-d1);
        if (lambda < 0.1) {
          lambda = 0.1;
-@@ -3998,11 +3998,11 @@ int wcsmix(
+@@ -3998,14 +4239,14 @@ int wcsmix(
          return status;
        }
  
@@ -25486,8 +28923,12 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
 +        // Recall saved world coordinates.
          *worldlng = lng;
          *worldlat = lat;
-         return 0;
-@@ -4019,11 +4019,11 @@ int wcsmix(
+-        return 0;
++        return WCSERR_SUCCESS;
+       }
+ 
+       if (signbit(d0) == signbit(d)) {
+@@ -4019,11 +4260,199 @@ int wcsmix(
    }
  
  
@@ -25497,21 +28938,218 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  }
  
 -/*--------------------------------------------------------------------------*/
++//----------------------------------------------------------------------------
++
++int wcsccs(
++  struct wcsprm *wcs,
++  double lng2P1,
++  double lat2P1,
++  double lng1P2,
++  const char *clng,
++  const char *clat,
++  const char *radesys,
++  double equinox,
++  const char *alt)
++
++{
++  static const char *function = "wcsccs";
++
++  int status;
++
++  // Initialize if required.
++  if (wcs == 0x0) return WCSERR_NULL_POINTER;
++  struct wcserr **err = &(wcs->err);
++
++  if (wcs->flag != WCSSET) {
++    if ((status = wcsset(wcs))) return status;
++  }
++
++  if (wcs->lng < 0 || wcs->lat < 0) {
++    return wcserr_set(WCSERR_SET(WCSERR_BAD_SUBIMAGE),
++      "Image does not have celestial axes");
++  }
++
++  // (lng1XX,lat1XX)  ...longitude and latitude of XX in the old system.
++  // (lng2XX,lat2XX)  ...longitude and latitude of XX in the new system.
++  // XX = NP          ...natuve pole,
++  //      P1          ...pole of the old system,
++  //      P2          ...pole of the new system,
++  //      FP          ...fiducial point.
++
++  // Set up the transformation from the old to the new system.
++  double euler12[5];
++  euler12[0] = lng2P1;
++  euler12[1] = 90.0 - lat2P1;
++  euler12[2] = lng1P2;
++  euler12[3] = cosd(euler12[1]);
++  euler12[4] = sind(euler12[1]);
++
++  // Transform coordinates of the fiducial point (FP) to the new system.
++  double lng1FP = wcs->crval[wcs->lng];
++  double lat1FP = wcs->crval[wcs->lat];
++  double lng2FP, lat2FP;
++  (void)sphx2s(euler12, 1, 1, 1, 1, &lng1FP, &lat1FP, &lng2FP, &lat2FP);
++
++  // Compute native coordinates of the new pole (noting lat1P2 == lat2P1).
++  double phiP2, thetaP2;
++  (void)sphs2x(wcs->cel.euler, 1, 1, 1, 1, &lng1P2, &lat2P1,
++               &phiP2, &thetaP2);
++
++  if (fabs(lat2FP) == 90.0 || fabs(thetaP2) == 90.0) {
++    // If one of the poles of the new system is at the fiducial point, then
++    // lng2FP is indeterminate, and if one of them is at the native pole, then
++    // phiP2 is indeterminate.  We have to work harder to obtain these values.
++
++    // Compute coordinates of the native pole (NP) in the old and new systems.
++    double phiNP = 0.0, thetaNP = 90.0;
++    double lng1NP, lat1NP;
++    (void)sphx2s(wcs->cel.euler, 1, 1, 1, 1, &phiNP, &thetaNP,
++                 &lng1NP, &lat1NP);
++
++    double lng2NP, lat2NP;
++    (void)sphx2s(euler12, 1, 1, 1, 1, &lng1NP, &lat1NP, &lng2NP, &lat2NP);
++
++    // Native latitude and longitude of the fiducial point, (phi0,theta0).
++    double phiFP   = wcs->cel.prj.phi0;
++    double thetaFP = wcs->cel.prj.theta0;
++
++    if (fabs(lat2NP) == 90.0) {
++      // Following WCS Paper II equations (3) and (4), we are free to choose
++      // phiP2 and set lng2NP accordingly.  So set phiP2 to its default value
++      // for the projection.
++      if (thetaFP < lat2FP) {
++        phiP2 = 0.0;
++      } else {
++        phiP2 = 180.0;
++      }
++
++      // Compute coordinates in the old system of test point X.
++      double phiX = 0.0, thetaX = 0.0;
++      double lng1X, lat1X;
++      (void)sphx2s(wcs->cel.euler, 1, 1, 1, 1, &phiX, &thetaX,
++                   &lng1X, &lat1X);
++
++      // Ensure that lng1X is not indeterminate.
++      if (fabs(lat1X) == 90.0) {
++        phiX = 90.0;
++        (void)sphx2s(wcs->cel.euler, 1, 1, 1, 1, &phiX, &thetaX,
++                     &lng1X, &lat1X);
++      }
++
++      // Compute coordinates in the new system of test point X.
++      double lng2X, lat2X;
++      (void)sphx2s(euler12, 1, 1, 1, 1, &lng1X, &lat1X, &lng2X, &lat2X);
++
++      // Apply WCS Paper II equations (3) and (4).
++      if (lat2NP == +90.0) {
++        lng2NP = lng2X + (phiP2 - phiX) + 180.0;
++      } else {
++        lng2NP = lng2X - (phiP2 - phiX);
++      }
++
++    } else {
++      // For (lng2NP + 90, 0), WCS Paper II equation (5) reduces to
++      // phi = phiP2 - 90.
++      double lng2X = lng2NP + 90.0;
++      double lat2X = 0.0;
++      double lng1X, lat1X;
++      (void)sphs2x(euler12, 1, 1, 1, 1, &lng2X, &lat2X, &lng1X, &lat1X);
++
++      double phiX, thetaX;
++      (void)sphs2x(wcs->cel.euler, 1, 1, 1, 1, &lng1X, &lat1X,
++                   &phiX, &thetaX);
++
++      phiP2 = phiX + 90.0;
++    }
++
++    // Compute the longitude of the fiducial point in the new system.
++    double eulerN2[5];
++    eulerN2[0] = lng2NP;
++    eulerN2[1] = 90.0 - lat2NP;
++    eulerN2[2] = phiP2;
++    eulerN2[3] = cosd(eulerN2[1]);
++    eulerN2[4] = sind(eulerN2[1]);
++
++    (void)sphx2s(eulerN2, 1, 1, 1, 1, &phiFP, &thetaFP, &lng2FP, &lat2FP);
++  }
++
++  // Update reference values in wcsprm.
++  wcs->flag = 0;
++  wcs->crval[wcs->lng] = lng2FP;
++  wcs->crval[wcs->lat] = lat2FP;
++  wcs->lonpole = phiP2;
++  wcs->latpole = thetaP2;
++
++  // Update wcsprm::ctype.
++  if (clng) {
++    strncpy(wcs->ctype[wcs->lng], clng, 4);
++    for (int i = 0; i < 4; i++) {
++      if (wcs->ctype[wcs->lng][i] == '\0') {
++        wcs->ctype[wcs->lng][i] = '-';
++      }
++    }
++  }
++
++  if (clat) {
++    strncpy(wcs->ctype[wcs->lat], clat, 4);
++    for (int i = 0; i < 4; i++) {
++      if (wcs->ctype[wcs->lat][i] == '\0') {
++        wcs->ctype[wcs->lat][i] = '-';
++      }
++    }
++  }
++
++  // Update auxiliary values.
++  if (strncmp(wcs->ctype[wcs->lng], "RA--", 4) == 0 &&
++      strncmp(wcs->ctype[wcs->lat], "DEC-", 4) == 0) {
++    // Transforming to equatorial coordinates.
++    if (radesys) {
++      strncpy(wcs->radesys, radesys, 71);
++    }
++
++    if (equinox != 0.0) {
++      wcs->equinox = equinox;
++    }
++  } else {
++    // Meaningless for other than equatorial coordinates.
++    memset(wcs->radesys, 0, 72);
++    wcs->equinox = UNDEFINED;
++  }
++
++  if (alt && *alt) {
++    wcs->alt[0] = *alt;
++  }
++
++  // Reset the struct.
++  if ((status = wcsset(wcs))) return status;
++
++  return WCSERR_SUCCESS;
++}
++
 +//----------------------------------------------------------------------------
  
  int wcssptr(
    struct wcsprm *wcs,
-@@ -4037,7 +4037,7 @@ int wcssptr(
-   double cdelt, crval;
-   struct wcserr **err;
+@@ -4033,21 +4462,20 @@ int wcssptr(
+ {
+   static const char *function = "wcssptr";
+ 
+-  int    j, status;
+-  double cdelt, crval;
+-  struct wcserr **err;
++  int status;
  
 -  /* Initialize if required. */
 +  // Initialize if required.
    if (wcs == 0x0) return WCSERR_NULL_POINTER;
-   err = &(wcs->err);
+-  err = &(wcs->err);
++  struct wcserr **err = &(wcs->err);
  
-@@ -4047,7 +4047,7 @@ int wcssptr(
+   if (wcs->flag != WCSSET) {
+     if ((status = wcsset(wcs))) return status;
+   }
  
++  int j;
    if ((j = *i) < 0) {
      if ((j = wcs->spec) < 0) {
 -      /* Look for a linear spectral axis. */
@@ -25519,25 +29157,28 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
        for (j = 0; j < wcs->naxis; j++) {
          if (wcs->types[j]/100 == 30) {
            break;
-@@ -4055,7 +4055,7 @@ int wcssptr(
+@@ -4055,16 +4483,17 @@ int wcssptr(
        }
  
        if (j >= wcs->naxis) {
 -        /* No spectral axis. */
 +        // No spectral axis.
          return wcserr_set(WCSERR_SET(WCSERR_BAD_SUBIMAGE),
-           "No spectral axis found.");
+-          "No spectral axis found.");
++          "No spectral axis found");
        }
-@@ -4064,7 +4064,7 @@ int wcssptr(
+     }
+ 
      *i = j;
    }
  
 -  /* Translate the spectral axis. */
 +  // Translate the spectral axis.
++  double cdelt, crval;
    if ((status = spctrne(wcs->ctype[j], wcs->crval[j], wcs->cdelt[j],
                          wcs->restfrq, wcs->restwav, ctype, &crval, &cdelt,
                          &(wcs->spc.err)))) {
-@@ -4072,21 +4072,21 @@ int wcssptr(
+@@ -4072,21 +4501,24 @@ int wcssptr(
    }
  
  
@@ -25554,7 +29195,11 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
    spcfree(&(wcs->spc));
    spcini(&(wcs->spc));
  
-   return 0;
+-  return 0;
++  // Reset the struct.
++  if ((status = wcsset(wcs))) return status;
++
++  return WCSERR_SUCCESS;
  }
  
 -/*--------------------------------------------------------------------------*/
@@ -25562,16 +29207,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.c
  
  #define STRINGIZE(s) STRINGIFY(s)
  #define STRINGIFY(s) #s
-Index: astropy-4.2/cextern/wcslib/C/wcs.h
+Index: astropy-4.2.1/cextern/wcslib/C/wcs.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcs.h
-+++ astropy-4.2/cextern/wcslib/C/wcs.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcs.h
++++ astropy-4.2.1/cextern/wcslib/C/wcs.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -25585,15 +29230,48 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcs.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcs.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcs.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
-@@ -358,38 +355,39 @@
+@@ -67,12 +64,13 @@
+ * set by the user, and others that are maintained by these routines, somewhat
+ * like a C++ class but with no encapsulation.
+ *
+-* wcsnpv(), wcsnps(), wcsini(), wcsinit(), wcssub(), and wcsfree() are
+-* provided to manage the wcsprm struct and another, wcsprt(), prints its
+-* contents.  Refer to the description of the wcsprm struct for an explanation
+-* of the anticipated usage of these routines.  wcscopy(), which does a deep
+-* copy of one wcsprm struct to another, is defined as a preprocessor macro
+-* function that invokes wcssub().
++* wcsnpv(), wcsnps(), wcsini(), wcsinit(), wcssub(), wcsfree(), and wcstrim(),
++* are provided to manage the wcsprm struct, wcssize() computes its total size
++* including allocated memory, and wcsprt() prints its contents.  Refer to the
++* description of the wcsprm struct for an explanation of the anticipated usage
++* of these routines.  wcscopy(), which does a deep copy of one wcsprm struct
++* to another, is defined as a preprocessor macro function that invokes
++* wcssub().
+ *
+ * wcsperr() prints the error message(s) (if any) stored in a wcsprm struct,
+ * and the linprm, celprm, prjprm, spcprm, and tabprm structs that it contains.
+@@ -91,8 +89,10 @@
+ * pixel coordinate a hybrid routine, wcsmix(), iteratively solves for the
+ * unknown elements.
+ *
+-* wcssptr() translates the spectral axis in a wcsprm struct.  For example, a
+-* 'FREQ' axis may be translated into 'ZOPT-F2W' and vice versa.
++* wcsccs() changes the celestial coordinate system of a wcsprm struct, for
++* example, from equatorial to galactic, and wcssptr() translates the spectral
++* axis.  For example, a 'FREQ' axis may be translated into 'ZOPT-F2W' and vice
++* versa.
+ *
+ * wcslib_version() returns the WCSLIB version number.
+ *
+@@ -358,38 +358,39 @@
  *                       wcsprm::err if enabled, see wcserr_enable().
  *
  * Notes:
@@ -25665,7 +29343,108 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.h
  *
  *
  * wcscompare() - Compare two wcsprm structs for equality
-@@ -561,9 +559,9 @@
+@@ -450,7 +451,7 @@
+ * PLEASE NOTE: wcsfree() must not be invoked on a wcsprm struct that was not
+ * initialized by wcsinit().
+ *
+-* Returned:
++* Given and returned:
+ *   wcs       struct wcsprm*
+ *                       Coordinate transformation parameters.
+ *
+@@ -460,6 +461,91 @@
+ *                         1: Null wcsprm pointer passed.
+ *
+ *
++* wcstrim() - Free unused arrays in the wcsprm struct
++* ---------------------------------------------------
++* wcstrim() frees memory allocated by wcsinit() for arrays in the wcsprm
++* struct that remains unused after it has been set up by wcsset().
++*
++* The free'd array members are associated with FITS WCS keyrecords that are
++* rarely used and usually just bloat the struct: wcsprm::crota, wcsprm::colax,
++* wcsprm::cname, wcsprm::crder, wcsprm::csyer, wcsprm::czphs, and
++* wcsprm::cperi.  If unused, wcsprm::pv, wcsprm::ps, and wcsprm::cd are also
++* freed.
++*
++* Once these arrays have been freed, a test such as
++=
++=        if (!undefined(wcs->cname[i])) {...}
++=
++* must be protected as follows
++=
++=        if (wcs->cname && !undefined(wcs->cname[i])) {...}
++=
++* In addition, if wcsprm::npv is non-zero but less than wcsprm::npvmax, then
++* the unused space in wcsprm::pv will be recovered (using realloc()).
++* Likewise for wcsprm::ps.
++*
++* Given and returned:
++*   wcs       struct wcsprm*
++*                       Coordinate transformation parameters.
++*
++* Function return value:
++*             int       Status return value:
++*                         0: Success.
++*                         1: Null wcsprm pointer passed.
++*                        14: wcsprm struct is unset.
++*
++*
++* wcssize() - Compute the size of a wcsprm struct
++* -----------------------------------------------
++* wcssize() computes the full size of a wcsprm struct, including allocated
++* memory.
++*
++* Given:
++*   wcs       const struct wcsprm*
++*                       Coordinate transformation parameters.
++*
++*                       If NULL, the base size of the struct and the allocated
++*                       size are both set to zero.
++*
++* Returned:
++*   sizes     int[2]    The first element is the base size of the struct as
++*                       returned by sizeof(struct wcsprm).  The second element
++*                       is the total allocated size, in bytes, assuming that
++*                       the allocation was done by wcsini().  This figure
++*                       includes memory allocated for members of constituent
++*                       structs, such as wcsprm::lin.
++*
++*                       It is not an error for the struct not to have been set
++*                       up via wcsset(), which normally results in additional
++*                       memory allocation. 
++*
++* Function return value:
++*             int       Status return value:
++*                         0: Success.
++*
++*
++* auxsize() - Compute the size of a auxprm struct
++* -----------------------------------------------
++* auxsize() computes the full size of a auxprm struct, including allocated
++* memory.
++*
++* Given:
++*   aux       const struct auxprm*
++*                       Auxiliary coordinate information.
++*
++*                       If NULL, the base size of the struct and the allocated
++*                       size are both set to zero.
++*
++* Returned:
++*   sizes     int[2]    The first element is the base size of the struct as
++*                       returned by sizeof(struct auxprm).  The second element
++*                       is the total allocated size, in bytes, currently zero.
++*
++* Function return value:
++*             int       Status return value:
++*                         0: Success.
++*
++*
+ * wcsprt() - Print routine for the wcsprm struct
+ * ----------------------------------------------
+ * wcsprt() prints the contents of a wcsprm struct using wcsprintf().  Mainly
+@@ -561,9 +647,9 @@
  *                       wcsprm::err if enabled, see wcserr_enable().
  *
  * Notes:
@@ -25678,7 +29457,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.h
  *
  *
  * wcsp2s() - Pixel-to-world transformation
-@@ -780,31 +778,31 @@
+@@ -780,31 +866,167 @@
  *                       wcsprm::err if enabled, see wcserr_enable().
  *
  * Notes:
@@ -25732,10 +29511,158 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.h
 +*      compute-limited applications more efficient special-case solvers could
 +*      be written for simple projections, for example non-oblique cylindrical
 +*      projections.
++*
++*
++* wcsccs() - Change celestial coordinate system
++* ---------------------------------------------
++* wcsccs() changes the celestial coordinate system of a wcsprm struct.  For
++* example, from equatorial to galactic coordinates.
++*
++* Parameters that define the spherical coordinate transformation, essentially
++* being three Euler angles, must be provided.  Thereby wcsccs() does not need
++* prior knowledge of specific celestial coordinate systems.  It also has the
++* advantage of making it completely general.
++*
++* Auxiliary members of the wcsprm struct relating to equatorial celestial
++* coordinate systems may also be changed.
++*
++* Only orthodox spherical coordinate systems are supported.  That is, they
++* must be right-handed, with latitude increasing from zero at the equator to
++* +90 degrees at the pole.  This precludes systems such as aziumuth and zenith
++* distance, which, however, could be handled as negative azimuth and
++* elevation.
++*
++* PLEASE NOTE: Information in the wcsprm struct relating to the original
++* coordinate system will be overwritten and therefore lost.  If this is
++* undesirable, invoke wcsccs() on a copy of the struct made with wcssub().
++* The wcsprm struct is reset on return with an explicit call to wcsset().
++*
++* Given and returned:
++*   wcs       struct wcsprm*
++*                       Coordinate transformation parameters.  Particular
++*                       "values to be given" elements of the wcsprm struct
++*                       are modified.
++*
++* Given:
++*   lng2p1,
++*   lat2p1    double    Longitude and latitude in the new celestial coordinate
++*                       system of the pole (i.e. latitude +90) of the original
++*                       system [deg].  See notes 1 and 2 below.
++*
++*   lng1p2    double    Longitude in the original celestial coordinate system
++*                       of the pole (i.e. latitude +90) of the new system
++*                       [deg].  See note 1 below.
++*
++*   clng,clat const char*
++*                       Longitude and latitude identifiers of the new CTYPEia
++*                       celestial axis codes, without trailing dashes.  For
++*                       example, "RA" and "DEC" or "GLON" and "GLAT".  Up to
++*                       four characters are used, longer strings need not be
++*                       null-terminated.
++*
++*   radesys   const char*
++*                       Used when transforming to equatorial coordinates,
++*                       identified by clng == "RA" and clat = "DEC".  May be
++*                       set to the null pointer to preserve the current value.
++*                       Up to 71 characters are used, longer strings need not
++*                       be null-terminated.
++*
++*                       If the new coordinate system is anything other than
++*                       equatorial, then wcsprm::radesys will be cleared.
++*
++*   equinox   double    Used when transforming to equatorial coordinates.  May
++*                       be set to zero to preserve the current value.
++*
++*                       If the new coordinate system is not equatorial, then
++*                       wcsprm::equinox will be marked as undefined.
++*
++*   alt       const char*
++*                       Character code for alternate coordinate descriptions
++*                       (i.e. the 'a' in keyword names such as CTYPEia).  This
++*                       is blank for the primary coordinate description, or
++*                       one of the 26 upper-case letters, A-Z.  May be set to
++*                       the null pointer, or null string if no change is
++*                       required.
++*
++* Function return value:
++*             int       Status return value:
++*                         0: Success.
++*                         1: Null wcsprm pointer passed.
++*                        12: Invalid subimage specification (no celestial
++*                            axes).
++*
++* Notes:
++*   1: Follows the prescription given in WCS Paper II, Sect. 2.7 for changing
++*      celestial coordinates.
++*
++*      The implementation takes account of indeterminacies that arise in that
++*      prescription in the particular cases where one of the poles of the new
++*      system is at the fiducial point, or one of them is at the native pole.
++*
++*   2: If lat2p1 == +90, i.e. where the poles of the two coordinate systems
++*      coincide, then the spherical coordinate transformation becomes a simple
++*      change in origin of longitude given by
++*      lng2 = lng1 + (lng2p1 - lng1p2 - 180), and lat2 = lat1, where
++*      (lng2,lat2) are coordinates in the new system, and (lng1,lat1) are
++*      coordinates in the original system.
++*
++*      Likewise, if lat2p1 == -90, then lng2 = -lng1 + (lng2p1 + lng1p2), and
++*      lat2 = -lat1.
++*
++*   3: For example, if the original coordinate system is B1950 equatorial and
++*      the desired new coordinate system is galactic, then
++*
++*      - (lng2p1,lat2p1) are the galactic coordinates of the B1950 celestial
++*        pole, defined by the IAU to be (123.0,+27.4), and lng1p2 is the B1950
++*        right ascension of the galactic pole, defined as 192.25.  Clearly
++*        these coordinates are fixed for a particular coordinate
++*        transformation.
++*
++*      - (clng,clat) would be 'GLON' and 'GLAT', these being the FITS standard
++*        identifiers for galactic coordinates.
++*
++*      - Since the new coordinate system is not equatorial, wcsprm::radesys
++*        and wcsprm::equinox will be cleared.
++*
++*   4. The coordinates required for some common transformations (obtained from
++*      https://ned.ipac.caltech.edu/coordinate_calculator) are as follows:
++*
++=      (123.0000,+27.4000) galactic coordinates of B1950 celestial pole,
++=      (192.2500,+27.4000) B1950 equatorial coordinates of galactic pole.
++*
++=      (122.9319,+27.1283) galactic coordinates of J2000 celestial pole,
++=      (192.8595,+27.1283) J2000 equatorial coordinates of galactic pole.
++*
++=      (359.6774,+89.7217) B1950 equatorial coordinates of J2000 pole,
++=      (180.3162,+89.7217) J2000 equatorial coordinates of B1950 pole.
++*
++=      (270.0000,+66.5542) B1950 equatorial coordinates of B1950 ecliptic pole,
++=      ( 90.0000,+66.5542) B1950 ecliptic coordinates of B1950 celestial pole.
++*
++=      (270.0000,+66.5607) J2000 equatorial coordinates of J2000 ecliptic pole,
++=      ( 90.0000,+66.5607) J2000 ecliptic coordinates of J2000 celestial pole.
++*
++=      ( 26.7315,+15.6441) supergalactic coordinates of B1950 celestial pole,
++=      (283.1894,+15.6441) B1950 equatorial coordinates of supergalactic pole.
++*
++=      ( 26.4505,+15.7089) supergalactic coordinates of J2000 celestial pole,
++=      (283.7542,+15.7089) J2000 equatorial coordinates of supergalactic pole.
  *
  *
  * wcssptr() - Spectral axis translation
-@@ -928,8 +926,8 @@
+@@ -812,6 +1034,11 @@
+ * wcssptr() translates the spectral axis in a wcsprm struct.  For example, a
+ * 'FREQ' axis may be translated into 'ZOPT-F2W' and vice versa.
+ *
++* PLEASE NOTE: Information in the wcsprm struct relating to the original
++* coordinate system will be overwritten and therefore lost.  If this is
++* undesirable, invoke wcssptr() on a copy of the struct made with wcssub().
++* The wcsprm struct is reset on return with an explicit call to wcsset().
++*
+ * Given and returned:
+ *   wcs       struct wcsprm*
+ *                       Coordinate transformation parameters.
+@@ -928,8 +1155,8 @@
  *       - wcsprm::wtb.
  *
  *     This signals the initialization routine, wcsset(), to recompute the
@@ -25746,7 +29673,83 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.h
  *
  *     PLEASE NOTE: flag should be set to -1 when wcsinit() is called for the
  *     first time for a particular wcsprm struct in order to initialize memory
-@@ -1730,7 +1728,7 @@
+@@ -1101,38 +1328,45 @@
+ *
+ *     - Bit 1: CDi_ja is present.
+ *
+-*       Matrix elements in the IRAF convention are
+-*       equivalent to the product CDi_ja = CDELTia * PCi_ja, but the
+-*       defaults differ from that of the PCi_ja matrix.  If one or more
+-*       CDi_ja keywords are present then all unspecified CDi_ja default to
+-*       zero.  If no CDi_ja (or CROTAi) keywords are present, then the
+-*       header is assumed to be in PCi_ja form whether or not any PCi_ja
+-*       keywords are present since this results in an interpretation of
+-*       CDELTia consistent with the original FITS specification.
++*       Matrix elements in the IRAF convention are equivalent to the product
++*       CDi_ja = CDELTia * PCi_ja, but the defaults differ from that of the
++*       PCi_ja matrix.  If one or more CDi_ja keywords are present then all
++*       unspecified CDi_ja default to zero.  If no CDi_ja (or CROTAi) keywords
++*       are present, then the header is assumed to be in PCi_ja form whether
++*       or not any PCi_ja keywords are present since this results in an
++*       interpretation of CDELTia consistent with the original FITS
++*       specification.
+ *
+ *       While CDi_ja may not formally co-exist with PCi_ja, it may co-exist
+ *       with CDELTia and CROTAi which are to be ignored.
+ *
+ *     - Bit 2: CROTAi is present.
+ *
+-*       In the AIPS convention, CROTAi may only be
+-*       associated with the latitude axis of a celestial axis pair.  It
+-*       specifies a rotation in the image plane that is applied AFTER the
+-*       CDELTia; any other CROTAi keywords are ignored.
++*       In the AIPS convention, CROTAi may only be associated with the
++*       latitude axis of a celestial axis pair.  It specifies a rotation in
++*       the image plane that is applied AFTER the CDELTia; any other CROTAi
++*       keywords are ignored.
+ *
+ *       CROTAi may not formally co-exist with PCi_ja.
+ *
+ *       CROTAi and CDELTia may formally co-exist with CDi_ja but if so are to
+ *       be ignored.
+ *
+-*     CDi_ja and CROTAi keywords, if found, are to be stored in the
+-*     wcsprm::cd and wcsprm::crota arrays which are dimensioned similarly to
+-*     wcsprm::pc and wcsprm::cdelt.  FITS
+-*     header parsers should use the following procedure:
++*     - Bit 3: PCi_ja + CDELTia was derived from CDi_ja by wcspcx().
++*
++*       This bit is set by wcspcx() when it derives PCi_ja and CDELTia from
++*       CDi_ja via an orthonormal decomposition.  In particular, it signals
++*       wcsset() not to replace PCi_ja by a copy of CDi_ja with CDELTia set
++*       to unity.
+ *
+-*     - Whenever a PCi_ja  keyword is encountered: altlin |= 1;
++*     CDi_ja and CROTAi keywords, if found, are to be stored in the wcsprm::cd
++*     and wcsprm::crota arrays which are dimensioned similarly to wcsprm::pc
++*     and wcsprm::cdelt.  FITS header parsers should use the following
++*     procedure:
+ *
+-*     - Whenever a CDi_ja  keyword is encountered: altlin |= 2;
++*     - Whenever a PCi_ja keyword is encountered: altlin |= 1;
++*
++*     - Whenever a CDi_ja keyword is encountered: altlin |= 2;
+ *
+ *     - Whenever a CROTAi keyword is encountered: altlin |= 4;
+ *
+@@ -1141,8 +1375,9 @@
+ *
+ *     These alternate specifications of the linear transformation matrix are
+ *     translated immediately to PCi_ja by wcsset() and are invisible to the
+-*     lower-level WCSLIB routines.  In particular, wcsset() resets
+-*     wcsprm::cdelt to unity if CDi_ja is present (and no PCi_ja).
++*     lower-level WCSLIB routines.  In particular, unless bit 3 is also set,
++*     wcsset() resets wcsprm::cdelt to unity if CDi_ja is present (and no
++*     PCi_ja).
+ *
+ *     If CROTAi are present but none is associated with the latitude axis
+ *     (and no PCi_ja or CDi_ja), then wcsset() reverts to a unity PCi_ja
+@@ -1730,7 +1965,7 @@
  
  #ifdef __cplusplus
  extern "C" {
@@ -25755,7 +29758,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.h
  #endif
  
  #define WCSSUB_LONGITUDE 0x1001
-@@ -1749,111 +1747,109 @@ extern "C" {
+@@ -1749,111 +1984,110 @@ extern "C" {
  extern const char *wcs_errmsg[];
  
  enum wcs_errmsg_enum {
@@ -25800,7 +29803,8 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.h
 +  WCSERR_NO_SOLUTION     = 11,	// No solution found in the specified
 +				// interval.
 +  WCSERR_BAD_SUBIMAGE    = 12,	// Invalid subimage specification.
-+  WCSERR_NON_SEPARABLE   = 13 	// Non-separable subimage coordinate system.
++  WCSERR_NON_SEPARABLE   = 13,	// Non-separable subimage coordinate system.
++  WCSERR_UNSET           = 14 	// wcsprm struct is unset.
  };
  
  
@@ -25931,8 +29935,8 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.h
 +  double *cd;			// CDi_ja linear transformation matrix.
 +  double *crota;		// CROTAi keyvalues for each coord axis.
 +  int    altlin;		// Alternative representations
-+				//   Bit 0: PCi_ja  is present,
-+				//   Bit 1: CDi_ja  is present,
++				//   Bit 0: PCi_ja is present,
++				//   Bit 1: CDi_ja is present,
 +				//   Bit 2: CROTAi is present.
 +  int    velref;		// AIPS velocity code, VELREF.
 +
@@ -25947,7 +29951,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.h
    char   (*cname)[72];
    double *crder;
    double *csyer;
-@@ -1861,22 +1857,22 @@ struct wcsprm {
+@@ -1861,22 +2095,22 @@ struct wcsprm {
    double *cperi;
  
    char   wcsname[72];
@@ -25974,7 +29978,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.h
    double obsgeo[6];
    char   obsorbit[72];
    char   radesys[72];
-@@ -1888,40 +1884,40 @@ struct wcsprm {
+@@ -1888,40 +2122,40 @@ struct wcsprm {
    char   ssyssrc[72];
    double velangl;
  
@@ -26044,7 +30048,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.h
    int    m_flag, m_naxis;
    double *m_crpix, *m_pc, *m_cdelt, *m_crval;
    char  (*m_cunit)[72], (*m_ctype)[72];
-@@ -1936,7 +1932,7 @@ struct wcsprm {
+@@ -1936,7 +2170,7 @@ struct wcsprm {
    struct wtbarr *m_wtb;
  };
  
@@ -26053,7 +30057,28 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.h
  #define WCSLEN (sizeof(struct wcsprm)/sizeof(int))
  
  
-@@ -1983,11 +1979,11 @@ int wcssptr(struct wcsprm *wcs, int *i,
+@@ -1959,6 +2193,12 @@ int wcscompare(int cmp, double tol, cons
+ 
+ int wcsfree(struct wcsprm *wcs);
+ 
++int wcstrim(struct wcsprm *wcs);
++
++int wcssize(const struct wcsprm *wcs, int sizes[2]);
++
++int auxsize(const struct auxprm *aux, int sizes[2]);
++
+ int wcsprt(const struct wcsprm *wcs);
+ 
+ int wcsperr(const struct wcsprm *wcs, const char *prefix);
+@@ -1979,15 +2219,19 @@ int wcsmix(struct wcsprm *wcs, int mixpi
+            double vstep, int viter, double world[], double phi[],
+            double theta[], double imgcrd[], double pixcrd[]);
+ 
++int wcsccs(struct wcsprm *wcs, double lng2p1, double lat2p1, double lng1p2,
++           const char *clng, const char *clat, const char *radesys,
++           double equinox, const char *alt);
++
+ int wcssptr(struct wcsprm *wcs, int *i, char ctype[9]);
  
  const char* wcslib_version(int vers[3]);
  
@@ -26067,22 +30092,22 @@ Index: astropy-4.2/cextern/wcslib/C/wcs.h
  #define wcsini_errmsg wcs_errmsg
  #define wcssub_errmsg wcs_errmsg
  #define wcscopy_errmsg wcs_errmsg
-@@ -2003,4 +1999,4 @@ const char* wcslib_version(int vers[3]);
+@@ -2003,4 +2247,4 @@ const char* wcslib_version(int vers[3]);
  }
  #endif
  
 -#endif /* WCSLIB_WCS */
 +#endif // WCSLIB_WCS
-Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
+Index: astropy-4.2.1/cextern/wcslib/C/wcsbth.l
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcsbth.l
-+++ astropy-4.2/cextern/wcslib/C/wcsbth.l
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcsbth.l
++++ astropy-4.2.1/cextern/wcslib/C/wcsbth.l
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -26096,11 +30121,19 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcsbth.l,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcsbth.l,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcsbth.l,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
  * wcsbth.l is a Flex description file containing the definition of a lexical
-@@ -125,30 +122,30 @@ INLINE " "*(\/.*)?
+@@ -76,6 +73,7 @@
+ %option outfile="wcsbth.c"
+ %option prefix="wcsbth"
+ %option reentrant
++%option extra-type="struct wcsbth_extra *"
+ 
+ /* Indices for parameterized keywords. */
+ Z1	[0-9]
+@@ -125,57 +123,34 @@ INLINE " "*(\/.*)?
  #include "wcsprintf.h"
  #include "wcsutil.h"
  
@@ -26123,6 +30156,37 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
 -#define BINTAB  0xC	/* BIMGARR | PIXLIST, i.e. binary table     */
 -			/* image array (without axis number) or     */
 -			/* pixel list, e.g. LONPna or OBSGXn.       */
+-
+-static int wcsbth_scanner(char *header, int nkeyrec, int relax, int ctrl,
+-                          int keysel, int *colsel, int *nreject, int *nwcs,
+-                          struct wcsprm **wcs, yyscan_t yyscanner);
+-
+-/*--------------------------------------------------------------------------*/
+-
+-int wcsbth(
+-  char *header,
+-  int nkeyrec,
+-  int relax,
+-  int ctrl,
+-  int keysel,
+-  int *colsel,
+-  int *nreject,
+-  int *nwcs,
+-  struct wcsprm **wcs)
+-
+-{
+-  int status;
+-  yyscan_t yyscanner;
+-  int yylex_init(yyscan_t *yyscanner);
+-  int yylex_destroy(yyscan_t yyscanner);
+-
+-  yylex_init(&yyscanner);
+-  status = wcsbth_scanner(header, nkeyrec, relax, ctrl, keysel, colsel,
+-                          nreject, nwcs, wcs, yyscanner);
+-  yylex_destroy(yyscanner);
+-
+-  return status;
+-}
 +			// Bit masks used for keyword types:
 +#define IMGAUX  0x1	// Auxiliary image header, e.g. LONPOLEa or
 +			// DATE-OBS.
@@ -26135,58 +30199,72 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
 +#define BINTAB  0xC	// BIMGARR | PIXLIST, i.e. binary table
 +			// image array (without axis number) or
 +			// pixel list, e.g. LONPna or OBSGXn.
- 
- static int wcsbth_scanner(char *header, int nkeyrec, int relax, int ctrl,
-                           int keysel, int *colsel, int *nreject, int *nwcs,
-                           struct wcsprm **wcs, yyscan_t yyscanner);
++
++// User data associated with yyscanner.
++struct wcsbth_extra {
++  // Values passed to YY_INPUT.
++  char *hdr;
++  int  nkeyrec;
  
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
- 
- int wcsbth(
-   char *header,
-@@ -175,7 +172,7 @@ int wcsbth(
-   return status;
- }
- 
--/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
++  // Used in preempting the call to exit() by yy_fatal_error().
++  jmp_buf abort_jmp_env;
++};
  
  #define YY_DECL int wcsbth_scanner(char *header, int nkeyrec, int relax, \
   int ctrl, int keysel, int *colsel, int *nreject, int *nwcs, \
-@@ -194,18 +191,18 @@ int wcsbth(
+@@ -183,29 +158,28 @@ int wcsbth(
+ 
+ #define YY_INPUT(inbuff, count, bufsize) \
+ 	{ \
+-	  if (wcsbth_nkeyrec) { \
+-	    strncpy(inbuff, wcsbth_hdr, 80); \
++	  if (yyextra->nkeyrec) { \
++	    strncpy(inbuff, yyextra->hdr, 80); \
+ 	    inbuff[80] = '\n'; \
+-	    wcsbth_hdr += 80; \
+-	    wcsbth_nkeyrec--; \
++	    yyextra->hdr += 80; \
++	    yyextra->nkeyrec--; \
+ 	    count = 81; \
+ 	  } else { \
+ 	    count = YY_NULL; \
  	  } \
  	}
  
 -/* A convenience macro to get around incompatibilities between unput() and
 -   yyless(): put yytext followed by a blank back onto the input stream. */
++// Preempt the call to exit() by yy_fatal_error().
++#define exit(status) longjmp(yyextra->abort_jmp_env, status);
++
 +// A convenience macro to get around incompatibilities between unput() and
 +// yyless(): put yytext followed by a blank back onto the input stream.
  #define WCSBTH_PUTBACK \
    sprintf(strtmp, "%s ", yytext); \
-   iz = strlen(strtmp); \
+-  iz = strlen(strtmp); \
++  size_t iz = strlen(strtmp); \
    while (iz) unput(strtmp[--iz]);
  
 -/* These global variables are required by YY_INPUT. */
-+// These global variables are required by YY_INPUT.
- static char *wcsbth_hdr;
- static int  wcsbth_nkeyrec;
- 
+-static char *wcsbth_hdr;
+-static int  wcsbth_nkeyrec;
+-
 -/* Struct used internally for header bookkeeping. */
 +// Struct used internally for header bookkeeping.
  struct wcsbth_alts {
    int ncol, ialt, icol, imgherit;
    short int (*arridx)[27];
-@@ -220,7 +217,7 @@ struct wcsbth_alts {
+@@ -220,7 +194,8 @@ struct wcsbth_alts {
    unsigned char pad2[2];
  };
  
 -/* Internal helper functions. */
 +// Internal helper functions.
++static YY_DECL;
  static int wcsbth_colax(struct wcsprm *wcs, struct wcsbth_alts *alts, int k,
          char a);
  static int wcsbth_final(struct wcsbth_alts *alts, int *nwcs,
-@@ -232,24 +229,24 @@ static int wcsbth_init1(struct wcsbth_al
+@@ -232,116 +207,99 @@ static int wcsbth_init1(struct wcsbth_al
  static int wcsbth_pass1(int keytype, int i, int j, int n, int k, char a,
          char ptype, struct wcsbth_alts *alts);
  
@@ -26203,112 +30281,185 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  static int wcsbth_timepixr(double timepixr);
  
 -/* Used in preempting the call to exit() by yy_fatal_error(). */
-+// Used in preempting the call to exit() by yy_fatal_error().
- jmp_buf wcsbth_abort_jmp_env;
- #define exit(status) longjmp(wcsbth_abort_jmp_env, status)
- 
+-jmp_buf wcsbth_abort_jmp_env;
+-#define exit(status) longjmp(wcsbth_abort_jmp_env, status)
+-
  %}
  
  %%
 -	/* Keyword indices, as used in the WCS papers, e.g. iVn_ma, TPn_ka. */
-+	// Keyword indices, as used in the WCS papers, e.g. iVn_ma, TPn_ka.
- 	char a;
- 	int  i, j, k, m, n;
- 	
-@@ -268,37 +265,37 @@ jmp_buf wcsbth_abort_jmp_env;
- 	int (*chekval)(double);
- 	int (*special)(double *, const double *);
+-	char a;
+-	int  i, j, k, m, n;
+-	
+-	char *cptr, *errmsg, errtxt[80], exclude[1000], gotone, *hptr, *keep,
+-	     *keyname, *keyrec, ptype, strtmp[80];
+-	int  altlin, auxprm, ialt, icol, incl, imherit, inttmp, ipass, ipx,
+-	     itmp, ix, jx, keytype, naux, nother, nsel, npass, nvalid, status,
+-	     valtype;
+-	ptrdiff_t voff;
+-	size_t iz;
++	char *errmsg, errtxt[80], *keyname, strtmp[80];
++	int  auxprm, inttmp;
+ 	double dbltmp, dbl2tmp[2];
+-	void   *vptr, *wptr;
+-	struct wcsbth_alts alts;
+-	struct auxprm *auxp, auxtem;
+-	struct wcsprm *wcsp, wcstem;
+-	int (*chekval)(double);
+-	int (*special)(double *, const double *);
++	struct auxprm auxtem;
++	struct wcsprm wcstem;
  	
 -	/* The data structures produced. */
-+	// The data structures produced.
++	// Initialize returned values.
++	*nreject = 0;
  	*nwcs = 0;
  	*wcs  = 0x0;
  	
 -	/* Parameters used to implement YY_INPUT. */
-+	// Parameters used to implement YY_INPUT.
- 	wcsbth_hdr = header;
- 	wcsbth_nkeyrec = nkeyrec;
- 	
+-	wcsbth_hdr = header;
+-	wcsbth_nkeyrec = nkeyrec;
+-	
 -	/* Our handle on the input stream. */
+-	keyrec = header;
+-	hptr = header;
+-	keep = 0x0;
 +	// Our handle on the input stream.
- 	keyrec = header;
- 	hptr = header;
- 	keep = 0x0;
++	char *keyrec = header;
++	char *hptr = header;
++	char *keep = 0x0;
++	
++	// For keeping tallies of keywords found.
++	int nvalid = 0;
++	int nother = 0;
  	
 -	/* For keeping tallies of keywords found. */
-+	// For keeping tallies of keywords found.
- 	*nreject = 0;
- 	nvalid = 0;
- 	nother = 0;
+-	*nreject = 0;
+-	nvalid = 0;
+-	nother = 0;
++	// Used to flag image header keywords that are always inherited.
++	int imherit = 1;
  	
 -	/* Used to flag image header keywords that are always inherited. */
-+	// Used to flag image header keywords that are always inherited.
- 	imherit = 1;
- 	
+-	imherit = 1;
+-	
 -	/* If strict, then also reject. */
 +	// If strict, then also reject.
  	if (relax & WCSHDR_strict) relax |= WCSHDR_reject;
  	
 -	/* Keyword parameters. */
-+	// Keyword parameters.
- 	i = j = 0;
- 	n = k = 0;
- 	m = 0;
- 	a = ' ';
+-	i = j = 0;
+-	n = k = 0;
+-	m = 0;
+-	a = ' ';
++	// Keyword indices, as used in the WCS papers, e.g. iVn_ma, TPn_ka.
++	int i = 0;
++	int j = 0;
++	int k = 0;
++	int n = 0;
++	int m = 0;
++	char a = ' ';
  	
 -	/* Header bookkeeping. */
 +	// Header bookkeeping.
++	struct wcsbth_alts alts;
  	alts.ncol = 0;
  	alts.arridx  = 0x0;
  	alts.pixlist = 0x0;
-@@ -311,12 +308,12 @@ jmp_buf wcsbth_abort_jmp_env;
+ 	alts.npv = 0x0;
+ 	alts.nps = 0x0;
+ 	
+-	for (ialt = 0; ialt < 27; ialt++) {
++	for (int ialt = 0; ialt < 27; ialt++) {
+ 	  alts.pixidx[ialt] = 0;
+ 	  alts.pixnpv[ialt] = 0;
  	  alts.pixnps[ialt] = 0;
  	}
  	
 -	/* For decoding the keyvalue. */
-+	// For decoding the keyvalue.
- 	keytype =  0;
- 	valtype = -1;
- 	vptr    = 0x0;
- 	
+-	keytype =  0;
+-	valtype = -1;
+-	vptr    = 0x0;
+-	
 -	/* For keywords that require special handling. */
-+	// For keywords that require special handling.
- 	altlin  = 0;
- 	ptype   = ' ';
- 	chekval = 0x0;
-@@ -324,7 +321,7 @@ jmp_buf wcsbth_abort_jmp_env;
- 	auxprm  = 0;
- 	naux    = 0;
- 	
+-	altlin  = 0;
+-	ptype   = ' ';
+-	chekval = 0x0;
+-	special = 0x0;
+-	auxprm  = 0;
+-	naux    = 0;
+-	
 -	/* Selection by column number. */
+-	nsel = colsel ? colsel[0] : 0;
+-	incl = (nsel > 0);
+-	for (icol = 0; icol < 1000; icol++) {
++	// For decoding the keyvalue.
++	int keytype =  0;
++	int valtype = -1;
++	void *vptr  = 0x0;
++	
++	// For keywords that require special handling.
++	int altlin  = 0;
++	char ptype  = ' ';
++	int (*chekval)(double) = 0x0;
++	int (*special)(double *, const double *) = 0x0;
++	struct auxprm *auxp = 0x0;
++	int naux = 0;
++	
 +	// Selection by column number.
- 	nsel = colsel ? colsel[0] : 0;
- 	incl = (nsel > 0);
- 	for (icol = 0; icol < 1000; icol++) {
-@@ -338,7 +335,7 @@ jmp_buf wcsbth_abort_jmp_env;
++	int nsel = colsel ? colsel[0] : 0;
++	int incl = (nsel > 0);
++	char exclude[1000];
++	for (int icol = 0; icol < 1000; icol++) {
+ 	  exclude[icol] = incl;
+ 	}
+-	for (icol = 1; icol <= abs(nsel); icol++) {
+-	  itmp = colsel[icol];
++	for (int icol = 1; icol <= abs(nsel); icol++) {
++	  int itmp = colsel[icol];
+ 	  if (0 < itmp && itmp < 1000) {
+ 	    exclude[itmp] = !incl;
+ 	  }
  	}
  	exclude[0] = 0;
  	
 -	/* Selection by keyword type. */
+-	itmp = keysel;
+-	keysel = 0;
+-	if (itmp) {
 +	// Selection by keyword type.
- 	itmp = keysel;
- 	keysel = 0;
- 	if (itmp) {
-@@ -350,11 +347,11 @@ jmp_buf wcsbth_abort_jmp_env;
++	if (keysel) {
++	  int itmp = keysel;
++	  keysel = 0;
+ 	  if (itmp & WCSHDR_IMGHEAD) keysel |= IMGHEAD;
+ 	  if (itmp & WCSHDR_BIMGARR) keysel |= BIMGARR;
+ 	  if (itmp & WCSHDR_PIXLIST) keysel |= PIXLIST;
+@@ -350,13 +308,17 @@ jmp_buf wcsbth_abort_jmp_env;
  	  keysel = IMGHEAD | BINTAB;
  	}
  	
 -	/* Control variables. */
-+	// Control variables.
- 	ipass = 1;
- 	npass = 2;
- 	
+-	ipass = 1;
+-	npass = 2;
+-	
 -	/* Return here via longjmp() invoked by yy_fatal_error(). */
+-	if (setjmp(wcsbth_abort_jmp_env)) {
+-	  return 4;
++	// Control variables.
++	int ipass = 1;
++	int npass = 2;
++	
++	// User data associated with yyscanner.
++	yyextra->hdr = header;
++	yyextra->nkeyrec = nkeyrec;
++	
 +	// Return here via longjmp() invoked by yy_fatal_error().
- 	if (setjmp(wcsbth_abort_jmp_env)) {
- 	  return 4;
++	if (setjmp(yyextra->abort_jmp_env)) {
++	  return WCSHDRERR_PARSER;
  	}
-@@ -379,7 +376,7 @@ jmp_buf wcsbth_abort_jmp_env;
+ 	
+ 	BEGIN(INITIAL);
+@@ -379,7 +341,7 @@ jmp_buf wcsbth_abort_jmp_env;
  
  ^WCSAXES{ALT}=" "" "*{INTEGER} {
  	  if (!(keysel & IMGAXIS)) {
@@ -26317,7 +30468,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	
  	  } else {
-@@ -404,7 +401,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -404,7 +366,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	      BEGIN(ERROR);
  	
  	    } else {
@@ -26326,7 +30477,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	      BEGIN(DISCARD);
  	    }
  	  }
-@@ -415,12 +412,12 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -415,12 +377,12 @@ jmp_buf wcsbth_abort_jmp_env;
  ^WCAX{I3}{ALT}"= "" "*{INTEGER} {
  	  keyname = "WCAXna";
  	
@@ -26342,7 +30493,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	
  	  } else if (i < 0) {
-@@ -440,7 +437,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -440,7 +402,7 @@ jmp_buf wcsbth_abort_jmp_env;
  ^WCST{I1}{ALT}"  = "" "*{STRING} |
  ^WCST{I2}{ALT}" = "" "*{STRING} |
  ^WCST{I3}{ALT}"= "" "*{STRING} {
@@ -26351,7 +30502,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	  keyname = "WCSTna";
  	  errmsg = "cross-references are not implemented";
  	  BEGIN(ERROR);
-@@ -449,7 +446,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -449,7 +411,7 @@ jmp_buf wcsbth_abort_jmp_env;
  ^WCSX{I1}{ALT}"  = "" "*{STRING} |
  ^WCSX{I2}{ALT}" = "" "*{STRING} |
  ^WCSX{I3}{ALT}"= "" "*{STRING} {
@@ -26360,7 +30511,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	  keyname = "WCSXna";
  	  errmsg = "cross-references are not implemented";
  	  BEGIN(ERROR);
-@@ -1247,7 +1244,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -1247,7 +1209,7 @@ jmp_buf wcsbth_abort_jmp_env;
  ^MJDREFI" " |
  ^MJD-REFI {
  	  if ((yytext[3] == 'R') || (relax & WCSHDR_DATEREF)) {
@@ -26369,7 +30520,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    valtype = FLOAT;
  	    vptr    = wcstem.mjdref;
  	
-@@ -1303,7 +1300,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -1303,7 +1265,7 @@ jmp_buf wcsbth_abort_jmp_env;
  ^JDREFI"  " |
  ^JD-REFI {
  	  if ((yytext[2] == 'R') || (relax & WCSHDR_DATEREF)) {
@@ -26378,7 +30529,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    valtype = FLOAT;
  	    vptr    = wcstem.mjdref;
  	    special = wcsbth_jdrefi;
-@@ -1850,7 +1847,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -1850,7 +1812,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26387,7 +30538,18 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -1971,7 +1968,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -1944,8 +1906,8 @@ jmp_buf wcsbth_abort_jmp_env;
+ 	}
+ 
+ ^END" "{77} {
+-	  if (wcsbth_nkeyrec) {
+-	    wcsbth_nkeyrec = 0;
++	  if (yyextra->nkeyrec) {
++	    yyextra->nkeyrec = 0;
+ 	    errmsg = "keyrecords following the END keyrecord were ignored";
+ 	    BEGIN(ERROR);
+ 	  } else {
+@@ -1971,7 +1933,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26396,7 +30558,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -1980,13 +1977,13 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -1980,13 +1942,13 @@ jmp_buf wcsbth_abort_jmp_env;
  <CCCCCia>00{I1} {
  	  if (relax & WCSHDR_ALLIMG) {
  	    if (relax & WCSHDR_reject) {
@@ -26412,7 +30574,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	      BEGIN(DISCARD);
  	    }
  	
-@@ -1997,7 +1994,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -1997,7 +1959,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26421,7 +30583,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2005,8 +2002,8 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2005,8 +1967,8 @@ jmp_buf wcsbth_abort_jmp_env;
  <CCCCCia>0{ALT}" " |
  <CCCCCia>00{ALT} |
  <CCCCCia>{Z3} {
@@ -26432,7 +30594,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	  if (relax & WCSHDR_ALLIMG) {
  	    errmsg = "axis number must exceed 0";
  	    BEGIN(ERROR);
-@@ -2018,21 +2015,21 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2018,21 +1980,21 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26457,7 +30619,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2076,7 +2073,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2076,7 +2038,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26466,7 +30628,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2119,7 +2116,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2119,7 +2081,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26475,7 +30637,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2158,7 +2155,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2158,7 +2120,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	      BEGIN(ERROR);
  	
  	    } else {
@@ -26484,7 +30646,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	      BEGIN(DISCARD);
  	    }
  	
-@@ -2169,7 +2166,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2169,7 +2131,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26493,7 +30655,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2184,8 +2181,8 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2184,8 +2146,8 @@ jmp_buf wcsbth_abort_jmp_env;
  <CCi_ja>{Z3}_{Z2} |
  <CCi_ja>{Z2}_{Z3} |
  <CCi_ja>{Z1}_{Z4} {
@@ -26504,7 +30666,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	  if (relax & WCSHDR_ALLIMG) {
  	    errmsg = "axis number must exceed 0";
  	    BEGIN(ERROR);
-@@ -2197,7 +2194,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2197,7 +2159,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26513,7 +30675,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2225,13 +2222,13 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2225,13 +2187,13 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26529,7 +30691,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	  if (relax & WCSHDR_ALLIMG) {
  	    if (((altlin == 1) && (relax & WCSHDR_PC00i00j)) ||
  	        ((altlin == 2) && (relax & WCSHDR_CD00i00j))) {
-@@ -2248,7 +2245,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2248,7 +2210,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	      BEGIN(ERROR);
  	
  	    } else {
@@ -26538,7 +30700,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	      BEGIN(DISCARD);
  	    }
  	
-@@ -2259,7 +2256,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2259,7 +2221,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26547,7 +30709,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2292,7 +2289,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2292,7 +2254,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26556,7 +30718,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2350,7 +2347,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2350,7 +2312,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	      BEGIN(ERROR);
  	
  	    } else {
@@ -26565,7 +30727,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	      BEGIN(DISCARD);
  	    }
  	
-@@ -2361,7 +2358,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2361,7 +2323,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26574,7 +30736,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2371,7 +2368,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2371,7 +2333,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    yyless(0);
  	    BEGIN(CCCCCia);
  	  } else {
@@ -26583,7 +30745,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2401,7 +2398,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2401,7 +2363,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26592,7 +30754,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2413,7 +2410,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2413,7 +2375,7 @@ jmp_buf wcsbth_abort_jmp_env;
  
  <CCCCCCCa>{ALT} |
  <CCCCCCCC>. {
@@ -26601,7 +30763,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	  if (imherit || (relax & (WCSHDR_AUXIMG | WCSHDR_ALLIMG))) {
  	    if (YY_START == CCCCCCCa) {
  	      sscanf(yytext, "%c", &a);
-@@ -2431,21 +2428,21 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2431,21 +2393,21 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26626,7 +30788,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2494,7 +2491,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2494,7 +2456,7 @@ jmp_buf wcsbth_abort_jmp_env;
  <CCi_ma>{I1}_{I2}{ALT}" " |
  <CCi_ma>{I2}_{Z1}{ALT}" " |
  <CCi_ma>{I2}_{I2}{ALT} {
@@ -26635,7 +30797,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	  if (relax & WCSHDR_ALLIMG) {
  	    sscanf(yytext, "%d_%d%c", &i, &m, &a);
  	    keytype = IMGAXIS;
-@@ -2507,7 +2504,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2507,7 +2469,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26644,7 +30806,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2546,7 +2543,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2546,7 +2508,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	      BEGIN(ERROR);
  	
  	    } else {
@@ -26653,7 +30815,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	      BEGIN(DISCARD);
  	    }
  	
-@@ -2557,7 +2554,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2557,7 +2519,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26662,7 +30824,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2573,8 +2570,8 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2573,8 +2535,8 @@ jmp_buf wcsbth_abort_jmp_env;
  <CCi_ma>{Z2}_{Z3} |
  <CCi_ma>{Z1}_{Z4} {
  	  if (relax & WCSHDR_ALLIMG) {
@@ -26673,7 +30835,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    errmsg = "axis number must exceed 0";
  	    BEGIN(ERROR);
  	
-@@ -2585,7 +2582,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2585,7 +2547,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26682,7 +30844,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2632,7 +2629,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2632,7 +2594,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26691,7 +30853,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2668,7 +2665,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2668,7 +2630,7 @@ jmp_buf wcsbth_abort_jmp_env;
  <TCn_ma>{I2}_{I3} |
  <TCn_ma>{I3}_{I2} |
  <TCn_ma>{I4}_{Z1} {
@@ -26700,7 +30862,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	  sscanf(yytext, "%d_%d", &n, &m);
  	  a = ' ';
  	  if (YY_START == TCn_ma) i = wcsbth_colax(*wcs, &alts, n, a);
-@@ -2694,7 +2691,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2694,7 +2656,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -26709,7 +30871,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -2715,16 +2712,16 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2715,17 +2677,17 @@ jmp_buf wcsbth_abort_jmp_env;
  	}
  
  <VALUE>=" "+ {
@@ -26726,12 +30888,14 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    if (k && (exclude[n] != exclude[k])) {
 -	      /* For keywords such as TCn_ka, both columns must be excluded.
 -	         User error, so return immediately. */
+-	      return 3;
 +	      // For keywords such as TCn_ka, both columns must be excluded.
 +	      // User error, so return immediately.
- 	      return 3;
++	      return WCSHDRERR_BAD_COLUMN;
  	
  	    } else {
-@@ -2744,18 +2741,18 @@ jmp_buf wcsbth_abort_jmp_env;
+ 	      BEGIN(DISCARD);
+@@ -2744,18 +2706,18 @@ jmp_buf wcsbth_abort_jmp_env;
  	      BEGIN(ERROR);
  	
  	    } else {
@@ -26754,7 +30918,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	      vptr = 0x0;
  	    }
  	
-@@ -2786,7 +2783,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2786,7 +2748,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(COMMENT);
  	
  	  } else {
@@ -26763,7 +30927,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    sscanf(yytext, "%d", &inttmp);
  	
  	    BEGIN(COMMENT);
-@@ -2803,7 +2800,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2803,7 +2765,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(COMMENT);
  	
  	  } else {
@@ -26772,7 +30936,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    wcsutil_str2double(yytext, &dbltmp);
  	
  	    if (chekval && chekval(dbltmp)) {
-@@ -2825,7 +2822,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2825,7 +2787,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(COMMENT);
  	
  	  } else {
@@ -26781,20 +30945,25 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    wcsutil_str2double2(yytext, dbl2tmp);
  	
  	    BEGIN(COMMENT);
-@@ -2842,10 +2839,10 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2842,12 +2804,12 @@ jmp_buf wcsbth_abort_jmp_env;
  	    BEGIN(COMMENT);
  	
  	  } else {
 -	    /* Read the keyvalue. */
+-	      strcpy(strtmp, yytext+1);
 +	    // Read the keyvalue.
- 	      strcpy(strtmp, yytext+1);
++	    strcpy(strtmp, yytext+1);
  	
 -	    /* Squeeze out repeated quotes. */
+-	    ix = 0;
+-	    for (jx = 0; jx < 72; jx++) {
 +	    // Squeeze out repeated quotes.
- 	    ix = 0;
- 	    for (jx = 0; jx < 72; jx++) {
++	    int ix = 0;
++	    for (int jx = 0; jx < 72; jx++) {
  	      if (ix < jx) {
-@@ -2873,28 +2870,28 @@ jmp_buf wcsbth_abort_jmp_env;
+ 	        strtmp[ix] = strtmp[jx];
+ 	      }
+@@ -2873,29 +2835,31 @@ jmp_buf wcsbth_abort_jmp_env;
  
  <COMMENT>{INLINE}$ {
  	  if (ipass == 1) {
@@ -26810,34 +30979,43 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	    alts.ialt = 0;
  	
 -	    /* Update each coordinate representation. */
+-	    gotone = 0;
 +	    // Update each coordinate representation.
- 	    gotone = 0;
++	    int gotone = 0;
++	    struct wcsprm *wcsp;
  	    while ((wcsp = wcsbth_idx(*wcs, &alts, keytype, n, a))) {
  	      gotone = 1;
  	
  	      if (vptr) {
++	        void *wptr;
  	        if (auxprm) {
 -	          /* Additional auxiliary parameter. */
 +	          // Additional auxiliary parameter.
  	          auxp = wcsp->aux;
- 	          voff = (char *)vptr - (char *)(&auxtem);
+-	          voff = (char *)vptr - (char *)(&auxtem);
++	          ptrdiff_t voff = (char *)vptr - (char *)(&auxtem);
  	          wptr = (void *)((char *)auxp + voff);
  	        } else {
 -	          /* A parameter that lives directly in wcsprm. */
+-	          voff = (char *)vptr - (char *)(&wcstem);
 +	          // A parameter that lives directly in wcsprm.
- 	          voff = (char *)vptr - (char *)(&wcstem);
++	          ptrdiff_t voff = (char *)vptr - (char *)(&wcstem);
  	          wptr = (void *)((char *)wcsp + voff);
  	        }
-@@ -2903,7 +2900,7 @@ jmp_buf wcsbth_abort_jmp_env;
+ 	
+@@ -2903,9 +2867,9 @@ jmp_buf wcsbth_abort_jmp_env;
  	          *((int *)wptr) = inttmp;
  	
  	        } else if (valtype == FLOAT) {
 -	          /* Apply keyword parameterization. */
 +	          // Apply keyword parameterization.
  	          if (ptype == 'v') {
- 	            ipx = (wcsp->npv)++;
+-	            ipx = (wcsp->npv)++;
++	            int ipx = (wcsp->npv)++;
  	            wcsp->pv[ipx].i = i;
-@@ -2924,14 +2921,14 @@ jmp_buf wcsbth_abort_jmp_env;
+ 	            wcsp->pv[ipx].m = m;
+ 	            wptr = &(wcsp->pv[ipx].value);
+@@ -2924,14 +2888,14 @@ jmp_buf wcsbth_abort_jmp_env;
  	            *((double *)wptr) = dbltmp;
  	          }
  	
@@ -26854,16 +31032,28 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	            if (special) {
  	              special(wptr, dbl2tmp);
  	            } else {
-@@ -2940,7 +2937,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -2940,9 +2904,9 @@ jmp_buf wcsbth_abort_jmp_env;
  	            }
  	
  	        } else if (valtype == STRING) {
 -	          /* Apply keyword parameterization. */
 +	          // Apply keyword parameterization.
  	          if (ptype == 's') {
- 	            ipx = wcsp->nps++;
+-	            ipx = wcsp->nps++;
++	            int ipx = wcsp->nps++;
  	            wcsp->ps[ipx].i = i;
-@@ -3009,7 +3006,7 @@ jmp_buf wcsbth_abort_jmp_env;
+ 	            wcsp->ps[ipx].m = m;
+ 	            wptr = wcsp->ps[ipx].value;
+@@ -2955,7 +2919,7 @@ jmp_buf wcsbth_abort_jmp_env;
+ 	            wptr = *((char (**)[72])wptr) + (i - 1);
+ 	          }
+ 	
+-	          cptr = (char *)wptr;
++	          char *cptr = (char *)wptr;
+ 	          strcpy(cptr, strtmp);
+ 	        }
+ 	      }
+@@ -3009,7 +2973,7 @@ jmp_buf wcsbth_abort_jmp_env;
  <DISCARD>.*$ {
  	  if (ipass == npass) {
  	    if (ctrl < 0) {
@@ -26872,7 +31062,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	      keep = keyrec;
  	
  	    } else if (2 < ctrl) {
-@@ -3047,7 +3044,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -3047,7 +3011,7 @@ jmp_buf wcsbth_abort_jmp_env;
  	
  	  naux += auxprm;
  	
@@ -26881,25 +31071,79 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
  	  i = j = 0;
  	  n = k = 0;
  	  m = 0;
-@@ -3069,7 +3066,7 @@ jmp_buf wcsbth_abort_jmp_env;
+@@ -3069,8 +3033,9 @@ jmp_buf wcsbth_abort_jmp_env;
  	}
  
  <<EOF>>	 {
 -	  /* End-of-input. */
 +	  // End-of-input.
  	  if (ipass == 1) {
++	    int status;
  	    if ((status = wcsbth_init1(&alts, naux, nwcs, wcs)) ||
  	        (*nwcs == 0 && ctrl == 0)) {
-@@ -3178,20 +3175,20 @@ int wcsbth_pass1(
-   int ialt, icol, mask, ncol;
+ 	      return status;
+@@ -3091,8 +3056,8 @@ jmp_buf wcsbth_abort_jmp_env;
+ 	  }
+ 	
+ 	  if (ipass++ < npass) {
+-	    wcsbth_hdr = header;
+-	    wcsbth_nkeyrec = nkeyrec;
++	    yyextra->hdr = header;
++	    yyextra->nkeyrec = nkeyrec;
+ 	    keyrec = header;
+ 	    *nreject = 0;
+ 	
+@@ -3139,6 +3104,36 @@ jmp_buf wcsbth_abort_jmp_env;
+ %%
  
+ /*----------------------------------------------------------------------------
++* External interface to the scanner.
++*---------------------------------------------------------------------------*/
++
++int wcsbth(
++  char *header,
++  int nkeyrec,
++  int relax,
++  int ctrl,
++  int keysel,
++  int *colsel,
++  int *nreject,
++  int *nwcs,
++  struct wcsprm **wcs)
++
++{
++  // Function prototypes.
++  int yylex_init_extra(YY_EXTRA_TYPE extra, yyscan_t *yyscanner);
++  int yylex_destroy(yyscan_t yyscanner);
++
++  struct wcsbth_extra extra;
++  yyscan_t yyscanner;
++  yylex_init_extra(&extra, &yyscanner);
++  int status = wcsbth_scanner(header, nkeyrec, relax, ctrl, keysel, colsel,
++                              nreject, nwcs, wcs, yyscanner);
++  yylex_destroy(yyscanner);
++
++  return status;
++}
++
++/*----------------------------------------------------------------------------
+ * Perform first-pass tasks:
+ *
+ * 1) Count the number of coordinate axes in each of the 27 possible alternate
+@@ -3175,23 +3170,21 @@ int wcsbth_pass1(
+   struct wcsbth_alts *alts)
+ 
+ {
+-  int ialt, icol, mask, ncol;
+-
    if (a == 0) {
 -    /* Keywords such as DATE-OBS go along for the ride. */
 +    // Keywords such as DATE-OBS go along for the ride.
      return 0;
    }
  
-   ncol = alts->ncol;
+-  ncol = alts->ncol;
++  int ncol = alts->ncol;
  
 -  /* Do we need to allocate memory for alts? */
 +  // Do we need to allocate memory for alts?
@@ -26917,7 +31161,14 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
          ncol = 999;
        }
      }
-@@ -3210,7 +3207,7 @@ int wcsbth_pass1(
+@@ -3204,13 +3197,13 @@ int wcsbth_pass1(
+       if (alts->npv)     free(alts->npv);
+       if (alts->nps)     free(alts->nps);
+       if (alts->pixlist) free(alts->pixlist);
+-      return 2;
++      return WCSHDRERR_MEMORY;
+     }
+ 
      alts->ncol = ncol;
  
    } else if (n > ncol || k > ncol) {
@@ -26926,16 +31177,30 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
      ncol = 999;
      if (!(alts->arridx  = realloc(alts->arridx,
                                      27*(1 + ncol)*sizeof(short int))) ||
-@@ -3227,7 +3224,7 @@ int wcsbth_pass1(
-       return 2;
+@@ -3224,12 +3217,12 @@ int wcsbth_pass1(
+       if (alts->npv)     free(alts->npv);
+       if (alts->nps)     free(alts->nps);
+       if (alts->pixlist) free(alts->pixlist);
+-      return 2;
++      return WCSHDRERR_MEMORY;
      }
  
 -    /* Since realloc() doesn't initialize the extra memory. */
+-    for (icol = (1 + alts->ncol); icol < (1 + ncol); icol++) {
+-      for (ialt = 0; ialt < 27; ialt++) {
 +    // Since realloc() doesn't initialize the extra memory.
-     for (icol = (1 + alts->ncol); icol < (1 + ncol); icol++) {
-       for (ialt = 0; ialt < 27; ialt++) {
++    for (int icol = (1 + alts->ncol); icol < (1 + ncol); icol++) {
++      for (int ialt = 0; ialt < 27; ialt++) {
          alts->arridx[icol][ialt] = 0;
-@@ -3245,18 +3242,18 @@ int wcsbth_pass1(
+         alts->npv[icol][ialt] = 0;
+         alts->nps[icol][ialt] = 0;
+@@ -3240,23 +3233,23 @@ int wcsbth_pass1(
+     alts->ncol = ncol;
+   }
+ 
+-  ialt = 0;
++  int ialt = 0;
+   if (a != ' ') {
      ialt = a - 'A' + 1;
    }
  
@@ -26959,7 +31224,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
        if (alts->arridx[n][ialt] < i) {
          alts->arridx[n][ialt] = i;
        }
-@@ -3273,17 +3270,17 @@ int wcsbth_pass1(
+@@ -3273,17 +3266,17 @@ int wcsbth_pass1(
      }
    }
  
@@ -26970,7 +31235,8 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
 +  // image arrays, never contribute to recognizing a table column as a pixel
 +  // list axis.  A PIXLIST keytype is required for that.
    if (keytype == PIXLIST) {
-     mask = 1 << ialt;
+-    mask = 1 << ialt;
++    int mask = 1 << ialt;
  
 -    /* n > 0 for PIXLIST keytypes. */
 +    // n > 0 for PIXLIST keytypes.
@@ -26982,16 +31248,34 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
      alts->pixlist[0] |= mask;
  
      if (ptype == 'v') {
-@@ -3320,7 +3317,7 @@ int wcsbth_init1(
+@@ -3311,22 +3304,20 @@ int wcsbth_init1(
+   struct wcsprm **wcs)
+ 
+ {
+-  int ialt, icol, inherit[27], ix, mask, ncol, npsmax, npvmax, status = 0;
+-  struct wcsprm *wcsp;
+-
++  int status = 0;
+ 
+   if (alts->arridx == 0x0) {
+     *nwcs = 0;
      return 0;
    }
  
 -  /* Determine the number of axes in each pixel list representation. */
+-  ncol = alts->ncol;
 +  // Determine the number of axes in each pixel list representation.
-   ncol = alts->ncol;
++  int ialt, mask, ncol = alts->ncol;
    for (ialt = 0, mask = 1; ialt < 27; ialt++, mask <<= 1) {
      alts->pixidx[ialt] = 0;
-@@ -3334,7 +3331,7 @@ int wcsbth_init1(
+ 
+     if (alts->pixlist[0] | mask) {
+-      for (icol = 1; icol <= ncol; icol++) {
++      for (int icol = 1; icol <= ncol; icol++) {
+         if (alts->pixlist[icol] & mask) {
+           alts->pixidx[ialt]++;
+         }
+@@ -3334,18 +3325,19 @@ int wcsbth_init1(
      }
    }
  
@@ -26999,10 +31283,13 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
 +  // Find the total number of coordinate representations.
    *nwcs = 0;
    alts->imgherit = 0;
-   for (ialt = 0; ialt < 27; ialt++) {
-@@ -3342,10 +3339,10 @@ int wcsbth_init1(
+-  for (ialt = 0; ialt < 27; ialt++) {
++  int inherit[27];
++  for (int ialt = 0; ialt < 27; ialt++) {
+     inherit[ialt] = 0;
  
-     for (icol = 1; icol <= ncol; icol++) {
+-    for (icol = 1; icol <= ncol; icol++) {
++    for (int icol = 1; icol <= ncol; icol++) {
        if (alts->arridx[icol][ialt] < 0) {
 -        /* No BIMGARR keytype but there's at least one BINTAB. */
 +        // No BIMGARR keytype but there's at least one BINTAB.
@@ -27014,7 +31301,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
            alts->arridx[icol][ialt] = alts->arridx[0][ialt];
          } else {
            alts->arridx[icol][ialt] = 0;
-@@ -3354,11 +3351,11 @@ int wcsbth_init1(
+@@ -3354,11 +3346,11 @@ int wcsbth_init1(
  
        if (alts->arridx[icol][ialt]) {
          if (alts->arridx[0][ialt]) {
@@ -27028,7 +31315,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
              alts->arridx[icol][ialt] = alts->arridx[0][ialt];
            }
          }
-@@ -3367,10 +3364,10 @@ int wcsbth_init1(
+@@ -3367,10 +3359,10 @@ int wcsbth_init1(
        }
      }
  
@@ -27041,7 +31328,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
          alts->arridx[0][ialt] = 0;
          alts->imgherit = 1;
        } else if (alts->arridx[0][ialt] > 0) {
-@@ -3378,7 +3375,7 @@ int wcsbth_init1(
+@@ -3378,7 +3370,7 @@ int wcsbth_init1(
        }
      }
  
@@ -27050,31 +31337,39 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
      if (alts->pixidx[ialt]) {
        (*nwcs)++;
      }
-@@ -3386,19 +3383,19 @@ int wcsbth_init1(
+@@ -3386,95 +3378,95 @@ int wcsbth_init1(
  
  
    if (*nwcs) {
 -    /* Allocate memory for the required number of wcsprm structs. */
 +    // Allocate memory for the required number of wcsprm structs.
      if (!(*wcs = calloc(*nwcs, sizeof(struct wcsprm)))) {
-       return 2;
+-      return 2;
++      return WCSHDRERR_MEMORY;
      }
  
 -    /* Initialize each wcsprm struct. */
+-    wcsp = *wcs;
 +    // Initialize each wcsprm struct.
-     wcsp = *wcs;
++    struct wcsprm *wcsp = *wcs;
      *nwcs = 0;
-     for (icol = 0; icol <= ncol; icol++) {
-       for (ialt = 0; ialt < 27; ialt++) {
+-    for (icol = 0; icol <= ncol; icol++) {
+-      for (ialt = 0; ialt < 27; ialt++) {
++    for (int icol = 0; icol <= ncol; icol++) {
++      for (int ialt = 0; ialt < 27; ialt++) {
          if (alts->arridx[icol][ialt] > 0) {
 -          /* Image-header representations that are not for inheritance
 -             (icol == 0) or binary table image array representations. */
 +          // Image-header representations that are not for inheritance
 +          // (icol == 0) or binary table image array representations.
            wcsp->flag = -1;
-           npvmax = alts->npv[icol][ialt];
-           npsmax = alts->nps[icol][ialt];
-@@ -3408,29 +3405,29 @@ int wcsbth_init1(
+-          npvmax = alts->npv[icol][ialt];
+-          npsmax = alts->nps[icol][ialt];
++          int npvmax = alts->npv[icol][ialt];
++          int npsmax = alts->nps[icol][ialt];
+           if ((status = wcsinit(1, (int)(alts->arridx[icol][ialt]), wcsp,
+                                 npvmax, npsmax, -1))) {
+             wcsvfree(nwcs, wcs);
              break;
            }
  
@@ -27110,16 +31405,21 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
            alts->arridx[icol][ialt] = -1;
          }
        }
-@@ -3438,7 +3435,7 @@ int wcsbth_init1(
+     }
  
-     for (ialt = 0; ialt < 27; ialt++) {
+-    for (ialt = 0; ialt < 27; ialt++) {
++    for (int ialt = 0; ialt < 27; ialt++) {
        if (alts->pixidx[ialt]) {
 -        /* Pixel lists representations. */
 +        // Pixel lists representations.
          wcsp->flag = -1;
-         npvmax = alts->pixnpv[ialt];
-         npsmax = alts->pixnps[ialt];
-@@ -3448,19 +3445,19 @@ int wcsbth_init1(
+-        npvmax = alts->pixnpv[ialt];
+-        npsmax = alts->pixnps[ialt];
++        int npvmax = alts->pixnpv[ialt];
++        int npsmax = alts->pixnps[ialt];
+         if ((status = wcsinit(1, (int)(alts->pixidx[ialt]), wcsp, npvmax,
+                               npsmax, -1))) {
+           wcsvfree(nwcs, wcs);
            break;
          }
  
@@ -27138,11 +31438,12 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
          }
  
 -        /* Record the pixel list column numbers. */
+-        mask = (1 << ialt);
 +        // Record the pixel list column numbers.
-         mask = (1 << ialt);
++        int icol, ix, mask = (1 << ialt);
          for (icol = 1, ix = 0; icol <= ncol; icol++) {
            if (alts->pixlist[icol] & mask) {
-@@ -3468,13 +3465,13 @@ int wcsbth_init1(
+             wcsp->colax[ix++] = icol;
            }
          }
  
@@ -27158,9 +31459,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
          alts->pixidx[ialt] = -1;
        }
      }
-@@ -3504,22 +3501,22 @@ struct wcsprm *wcsbth_idx(
+@@ -3498,28 +3490,27 @@ struct wcsprm *wcsbth_idx(
  
-   iwcs = -1;
+ {
+   const char as[] = " ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+-  int iwcs;
+ 
+   if (!wcs) return 0x0;
+ 
+-  iwcs = -1;
++  int iwcs = -1;
    for (; iwcs < 0 && alts->ialt < 27; alts->ialt++) {
 -    /* Note that a == 0 applies to every alternate, otherwise this
 -       loop simply determines the appropriate value of alts->ialt. */
@@ -27187,7 +31495,27 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
        alts->icol = 0;
      }
  
-@@ -3571,7 +3568,7 @@ int wcsbth_colax(
+@@ -3544,17 +3535,14 @@ int wcsbth_colax(
+   char a)
+ 
+ {
+-  int ix;
+-  struct wcsprm *wcsp;
+-
+   if (!wcs) return 0;
+ 
+-  wcsp = wcs;
++  struct wcsprm *wcsp = wcs;
+   if (a != ' ') {
+     wcsp += alts->pixidx[a-'A'+1];
+   }
+ 
+-  for (ix = 0; ix < wcsp->naxis; ix++) {
++  for (int ix = 0; ix < wcsp->naxis; ix++) {
+     if (wcsp->colax[ix] == n) {
+       return ++ix;
+     }
+@@ -3571,7 +3559,7 @@ int wcsbth_colax(
  int wcsbth_jdref(double *mjdref, const double *jdref)
  
  {
@@ -27196,7 +31524,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
    if (undefined(mjdref[0] && undefined(mjdref[1]))) {
      mjdref[0] = jdref[0] - 2400000.0;
      mjdref[1] = jdref[1] - 0.5;
-@@ -3588,7 +3585,7 @@ int wcsbth_jdref(double *mjdref, const d
+@@ -3588,7 +3576,7 @@ int wcsbth_jdref(double *mjdref, const d
  int wcsbth_jdrefi(double *mjdref, const double *jdrefi)
  
  {
@@ -27205,7 +31533,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
    if (undefined(mjdref[0])) {
      mjdref[0] = *jdrefi - 2400000.5;
    }
-@@ -3600,7 +3597,7 @@ int wcsbth_jdrefi(double *mjdref, const
+@@ -3600,7 +3588,7 @@ int wcsbth_jdrefi(double *mjdref, const
  int wcsbth_jdreff(double *mjdref, const double *jdreff)
  
  {
@@ -27214,7 +31542,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
    if (undefined(mjdref[1])) {
      mjdref[1] = *jdreff;
    }
-@@ -3616,7 +3613,7 @@ int wcsbth_jdreff(double *mjdref, const
+@@ -3616,7 +3604,7 @@ int wcsbth_jdreff(double *mjdref, const
  int wcsbth_epoch(double *equinox, const double *epoch)
  
  {
@@ -27223,37 +31551,52 @@ Index: astropy-4.2/cextern/wcslib/C/wcsbth.l
    if (undefined(*equinox)) {
      *equinox = *epoch;
    }
-@@ -3634,9 +3631,9 @@ int wcsbth_vsource(double *zsource, cons
+@@ -3632,12 +3620,12 @@ int wcsbth_epoch(double *equinox, const
+ int wcsbth_vsource(double *zsource, const double *vsource)
+ 
  {
-   double beta, c = 299792458.0;
+-  double beta, c = 299792458.0;
++  const double c = 299792458.0;
  
 -  /* If ZSOURCEa is currently undefined then set it from VSOURCEa. */
 +  // If ZSOURCEa is currently undefined then set it from VSOURCEa.
    if (undefined(*zsource)) {
 -    /* Convert relativistic Doppler velocity to redshift. */
+-    beta = *vsource/c;
 +    // Convert relativistic Doppler velocity to redshift.
-     beta = *vsource/c;
++    double beta = *vsource/c;
      *zsource = (1.0 + beta)/sqrt(1.0 - beta*beta) - 1.0;
    }
-@@ -3674,7 +3671,7 @@ int wcsbth_final(
+ 
+@@ -3666,15 +3654,14 @@ int wcsbth_final(
+   struct wcsprm **wcs)
+ 
+ {
+-  int ialt, status;
+-
+   if (alts->arridx)  free(alts->arridx);
+   if (alts->npv)     free(alts->npv);
+   if (alts->nps)     free(alts->nps);
    if (alts->pixlist) free(alts->pixlist);
  
-   for (ialt = 0; ialt < *nwcs; ialt++) {
+-  for (ialt = 0; ialt < *nwcs; ialt++) {
 -    /* Interpret -TAB header keywords. */
++  for (int ialt = 0; ialt < *nwcs; ialt++) {
 +    // Interpret -TAB header keywords.
++    int status;
      if ((status = wcstab(*wcs+ialt))) {
         wcsvfree(nwcs, wcs);
         return status;
-Index: astropy-4.2/cextern/wcslib/C/wcserr.c
+Index: astropy-4.2.1/cextern/wcslib/C/wcserr.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcserr.c
-+++ astropy-4.2/cextern/wcslib/C/wcserr.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcserr.c
++++ astropy-4.2.1/cextern/wcslib/C/wcserr.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -27268,7 +31611,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcserr.c
    Module author: Michael Droettboom
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcserr.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcserr.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcserr.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <stdarg.h>
@@ -27281,16 +31624,39 @@ Index: astropy-4.2/cextern/wcslib/C/wcserr.c
  
  int wcserr_enable(int enable)
  
-@@ -44,7 +41,7 @@ int wcserr_enable(int enable)
+@@ -44,7 +41,30 @@ int wcserr_enable(int enable)
    return wcserr_enabled = (enable ? 1 : 0);
  }
  
 -/*--------------------------------------------------------------------------*/
++//----------------------------------------------------------------------------
++
++int wcserr_size(const struct wcserr *err, int sizes[2])
++
++{
++  if (err == 0x0) {
++    sizes[0] = sizes[1] = 0;
++    return 0;
++  }
++
++  // Base size, in bytes.
++  sizes[0] = sizeof(struct wcserr);
++
++  // Total size of allocated memory, in bytes.
++  sizes[1] = 0;
++
++  if (err->msg) {
++    sizes[1] += strlen(err->msg) + 1;
++  }
++
++  return 0;
++}
++
 +//----------------------------------------------------------------------------
  
  int wcserr_prt(const struct wcserr *err, const char *prefix)
  
-@@ -66,7 +63,7 @@ int wcserr_prt(const struct wcserr *err,
+@@ -66,7 +86,7 @@ int wcserr_prt(const struct wcserr *err,
          prefix, err->status, err->function, err->line_no, err->file, prefix,
          err->msg);
      } else {
@@ -27299,7 +31665,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcserr.c
        wcsprintf("%sINFORMATIVE message from %s() at line %d of file "
          "%s:\n%s%s.\n", prefix, err->function, err->line_no, err->file,
          prefix, err->msg);
-@@ -76,7 +73,7 @@ int wcserr_prt(const struct wcserr *err,
+@@ -76,7 +96,7 @@ int wcserr_prt(const struct wcserr *err,
    return 0;
  }
  
@@ -27308,7 +31674,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcserr.c
  
  int wcserr_clear(struct wcserr **errp)
  
-@@ -92,7 +89,7 @@ int wcserr_clear(struct wcserr **errp)
+@@ -92,7 +112,7 @@ int wcserr_clear(struct wcserr **errp)
    return 0;
  }
  
@@ -27317,7 +31683,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcserr.c
  
  int wcserr_set(
    struct wcserr **errp,
-@@ -130,7 +127,7 @@ int wcserr_set(
+@@ -130,7 +150,7 @@ int wcserr_set(
      err->line_no  = line_no;
      err->msg      = 0x0;
  
@@ -27326,7 +31692,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcserr.c
      va_start(argp, format);
      msglen = vsnprintf(0x0, 0, format, argp) + 1;
      va_end(argp);
-@@ -140,7 +137,7 @@ int wcserr_set(
+@@ -140,7 +160,7 @@ int wcserr_set(
        return status;
      }
  
@@ -27335,7 +31701,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcserr.c
      va_start(argp, format);
      msglen = vsnprintf(err->msg, msglen, format, argp);
      va_end(argp);
-@@ -153,7 +150,7 @@ int wcserr_set(
+@@ -153,7 +173,7 @@ int wcserr_set(
    return status;
  }
  
@@ -27344,16 +31710,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcserr.c
  
  int wcserr_copy(const struct wcserr *src, struct wcserr *dst)
  
-Index: astropy-4.2/cextern/wcslib/C/wcserr.h
+Index: astropy-4.2.1/cextern/wcslib/C/wcserr.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcserr.h
-+++ astropy-4.2/cextern/wcslib/C/wcserr.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcserr.h
++++ astropy-4.2.1/cextern/wcslib/C/wcserr.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -27368,15 +31734,54 @@ Index: astropy-4.2/cextern/wcslib/C/wcserr.h
    Module author: Michael Droettboom
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcserr.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcserr.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcserr.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
-@@ -221,14 +218,14 @@ extern "C" {
+@@ -34,7 +31,7 @@
+ * ------------------------------
+ * Most of the structs in WCSLIB contain a pointer to a wcserr struct as a
+ * member.  Functions in WCSLIB that return an error status code can also
+-* allocate and set a detailed error message in this struct which also
++* allocate and set a detailed error message in this struct, which also
+ * identifies the function, source file, and line number where the error
+ * occurred.
+ *
+@@ -97,6 +94,29 @@
+ *                         1: Error messaging is enabled.
+ *
+ *
++* wcserr_size() - Compute the size of a wcserr struct
++* ---------------------------------------------------
++* wcserr_size() computes the full size of a wcserr struct, including allocated
++* memory.
++*
++* Given:
++*   err       const struct wcserr*
++*                       The error object.
++*
++*                       If NULL, the base size of the struct and the allocated
++*                       size are both set to zero.
++*
++* Returned:
++*   sizes     int[2]    The first element is the base size of the struct as
++*                       returned by sizeof(struct wcserr).  The second element
++*                       is the total allocated size of the message buffer, in
++*                       bytes.
++*
++* Function return value:
++*             int       Status return value:
++*                         0: Success.
++*
++*
+ * wcserr_prt() - Print a wcserr struct
+ * ------------------------------------
+ * wcserr_prt() prints the error message (if any) contained in a wcserr struct.
+@@ -221,35 +241,37 @@ extern "C" {
  #endif
  
  struct wcserr {
@@ -27397,7 +31802,11 @@ Index: astropy-4.2/cextern/wcslib/C/wcserr.h
  #define ERRLEN (sizeof(struct wcserr)/sizeof(int))
  
  int wcserr_enable(int enable);
-@@ -238,18 +235,18 @@ int wcserr_prt(const struct wcserr *err,
+ 
++int wcserr_size(const struct wcserr *err, int sizes[2]);
++
+ int wcserr_prt(const struct wcserr *err, const char *prefix);
+ 
  int wcserr_clear(struct wcserr **err);
  
  
@@ -27419,16 +31828,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcserr.h
  
 -#endif /* WSCLIB_WCSERR */
 +#endif // WSCLIB_WCSERR
-Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
+Index: astropy-4.2.1/cextern/wcslib/C/wcsfix.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcsfix.c
-+++ astropy-4.2/cextern/wcslib/C/wcsfix.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcsfix.c
++++ astropy-4.2.1/cextern/wcslib/C/wcsfix.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -27442,11 +31851,30 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcsfix.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcsfix.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcsfix.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <math.h>
-@@ -42,10 +39,10 @@
+@@ -30,22 +27,24 @@
+ #include <stdlib.h>
+ #include <string.h>
+ 
+-#include "wcserr.h"
+-#include "wcsmath.h"
+-#include "wcstrig.h"
+-#include "wcsutil.h"
+ #include "lin.h"
+ #include "sph.h"
++#include "tab.h"
+ #include "wcs.h"
+-#include "wcsunits.h"
++#include "wcserr.h"
+ #include "wcsfix.h"
++#include "wcsmath.h"
++#include "wcstrig.h"
++#include "wcsunits.h"
++#include "wcsutil.h"
++#include "wtbarr.h"
  
  extern const int WCSSET;
  
@@ -27459,7 +31887,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
  const char *wcsfix_errmsg[] = {
    "Success",
    "Null wcsprm pointer passed",
-@@ -59,36 +56,36 @@ const char *wcsfix_errmsg[] = {
+@@ -59,36 +58,36 @@ const char *wcsfix_errmsg[] = {
    "Could not determine reference pixel coordinate",
    "Could not determine reference pixel value"};
  
@@ -27518,7 +31946,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
  
  int wcsfix(int ctrl, const int naxis[], struct wcsprm *wcs, int stat[])
  
-@@ -126,7 +123,7 @@ int wcsfix(int ctrl, const int naxis[],
+@@ -126,7 +125,7 @@ int wcsfix(int ctrl, const int naxis[],
    return status;
  }
  
@@ -27527,9 +31955,13 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
  
  int wcsfixi(
    int ctrl,
-@@ -139,20 +136,20 @@ int wcsfixi(
-   int ifix, status = 0;
-   struct wcserr err;
+@@ -136,23 +135,23 @@ int wcsfixi(
+   struct wcserr info[])
+ 
+ {
+-  int ifix, status = 0;
+-  struct wcserr err;
++  int status = 0;
  
 -  /* Handling the status values returned from the sub-fixers is trickier than
 -  it might seem, especially considering that wcs->err may contain an error
@@ -27551,15 +31983,17 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
 +  // To get informative messages from spcfix() it must precede celfix() and
 +  // cylfix().  The latter call wcsset() which also translates AIPS-convention
 +  // spectral axes.
++  struct wcserr err;
    wcserr_copy(wcs->err, &err);
  
-   for (ifix = CDFIX; ifix < NWCSFIX; ifix++) {
+-  for (ifix = CDFIX; ifix < NWCSFIX; ifix++) {
 -    /* Clear (delete) wcs->err. */
++  for (int ifix = CDFIX; ifix < NWCSFIX; ifix++) {
 +    // Clear (delete) wcs->err.
      wcserr_clear(&(wcs->err));
  
      switch (ifix) {
-@@ -182,11 +179,11 @@ int wcsfixi(
+@@ -182,11 +181,11 @@ int wcsfixi(
      }
  
      if (stat[ifix] == FIXERR_NO_CHANGE) {
@@ -27573,7 +32007,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
        if (wcs->err && wcs->err->status < 0) {
          wcserr_copy(wcs->err, info+ifix);
        } else {
-@@ -194,17 +191,17 @@ int wcsfixi(
+@@ -194,17 +193,17 @@ int wcsfixi(
        }
  
      } else {
@@ -27594,7 +32028,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
    if (err.status) {
      wcserr_copy(&err, wcs->err);
    } else {
-@@ -214,7 +211,7 @@ int wcsfixi(
+@@ -214,39 +213,36 @@ int wcsfixi(
    return status;
  }
  
@@ -27603,7 +32037,10 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
  
  int cdfix(struct wcsprm *wcs)
  
-@@ -225,20 +222,20 @@ int cdfix(struct wcsprm *wcs)
+ {
+-  int  i, k, naxis, status = FIXERR_NO_CHANGE;
+-  double *cd;
+-
    if (wcs == 0x0) return FIXERR_NULL_POINTER;
  
    if ((wcs->altlin & 1) || !(wcs->altlin & 2)) {
@@ -27612,22 +32049,28 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
      return FIXERR_NO_CHANGE;
    }
  
-   naxis = wcs->naxis;
-   status = FIXERR_NO_CHANGE;
-   for (i = 0; i < naxis; i++) {
+-  naxis = wcs->naxis;
+-  status = FIXERR_NO_CHANGE;
+-  for (i = 0; i < naxis; i++) {
 -    /* Row of zeros? */
+-    cd = wcs->cd + i * naxis;
+-    for (k = 0; k < naxis; k++, cd++) {
++  int naxis  = wcs->naxis;
++  int status = FIXERR_NO_CHANGE;
++  for (int i = 0; i < naxis; i++) {
 +    // Row of zeros?
-     cd = wcs->cd + i * naxis;
-     for (k = 0; k < naxis; k++, cd++) {
++    double *cd = wcs->cd + i*naxis;
++    for (int k = 0; k < naxis; k++, cd++) {
        if (*cd != 0.0) goto next;
      }
  
 -    /* Column of zeros? */
 +    // Column of zeros?
      cd = wcs->cd + i;
-     for (k = 0; k < naxis; k++, cd += naxis) {
+-    for (k = 0; k < naxis; k++, cd += naxis) {
++    for (int k = 0; k < naxis; k++, cd += naxis) {
        if (*cd != 0.0) goto next;
-@@ -246,7 +243,7 @@ int cdfix(struct wcsprm *wcs)
+     }
  
      cd = wcs->cd + i * (naxis + 1);
      *cd = 1.0;
@@ -27636,7 +32079,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
  
  next: ;
    }
-@@ -254,7 +251,7 @@ next: ;
+@@ -254,13 +250,12 @@ next: ;
    return status;
  }
  
@@ -27645,7 +32088,29 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
  
  static int parse_date(const char *buf, int *hour, int *minute, double *sec)
  
-@@ -300,11 +297,11 @@ int datfix(struct wcsprm *wcs)
+ {
+   char ctmp[72];
+-
+   if (sscanf(buf, "%2d:%2d:%s", hour, minute, ctmp) < 3 ||
+       wcsutil_str2double(ctmp, sec)) {
+     return 1;
+@@ -274,7 +269,6 @@ static void write_date(char *buf, int ho
+ 
+ {
+   char ctmp[32];
+-
+   wcsutil_double2str(ctmp, "%04.1f", sec);
+   sprintf(buf, "T%.2d:%.2d:%s", hour, minute, ctmp);
+ }
+@@ -284,7 +278,6 @@ static char *newline(char **cp)
+ 
+ {
+   size_t k;
+-
+   if ((k = strlen(*cp))) {
+     *cp += k;
+     strcat(*cp, ".\n");
+@@ -300,32 +293,34 @@ int datfix(struct wcsprm *wcs)
  {
    static const char *function = "datfix";
  
@@ -27659,21 +32124,46 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
    const double djy = 365.25;
    const double dty = 365.242198781;
  
-@@ -322,10 +319,10 @@ int datfix(struct wcsprm *wcs)
-   status = FIXERR_NO_CHANGE;
+-  const char *dateid;
+-  char *cp, *date, infomsg[512], orig_date[72];
+-  int  day, dd, hour = 0, i, jd, minute = 0, month, msec, n4, status, year;
+-  double bepoch, jepoch, mjd[2], mjdsum, mjdtmp, sec = 0.0, t, *wcsmjd;
+-  struct wcserr **err;
++  int  day, hour = 0, minute = 0, month, year;
++  double sec = 0.0;
  
-   for (i = 0; i < 5; i++) {
+   if (wcs == 0x0) return FIXERR_NULL_POINTER;
+-  err = &(wcs->err);
++  struct wcserr **err = &(wcs->err);
+ 
+-  cp = infomsg;
++  char infomsg[512];
++  char *cp = infomsg;
+   *cp = '\0';
+-  status = FIXERR_NO_CHANGE;
+ 
+-  for (i = 0; i < 5; i++) {
 -    /* MJDREF is split into integer and fractional parts, wheres MJDOBS and
 -       the rest are a single value. */
++  int status = FIXERR_NO_CHANGE;
++
++  for (int i = 0; i < 5; i++) {
 +    // MJDREF is split into integer and fractional parts, wheres MJDOBS and
 +    // the rest are a single value.
++    const char *dateid;
++    char *date;
++    double *wcsmjd;
      if (i == 0) {
 -      /* Note, DATEREF and MJDREF, not DATE-REF and MJD-REF (sigh). */
 +      // Note, DATEREF and MJDREF, not DATE-REF and MJD-REF (sigh).
        dateid = "REF";
        date   = wcs->dateref;
        wcsmjd = wcs->mjdref;
-@@ -350,10 +347,10 @@ int datfix(struct wcsprm *wcs)
+@@ -347,55 +342,59 @@ int datfix(struct wcsprm *wcs)
+       wcsmjd = &(wcs->mjdend);
+     }
+ 
++    char orig_date[72];
      strncpy(orig_date, date, 72);
  
      if (date[0] == '\0') {
@@ -27686,12 +32176,13 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
          if (!undefined(wcs->jepoch)) {
            *wcsmjd = mjd2000 + (wcs->jepoch - 2000.0)*djy;
            sprintf(newline(&cp), "Set MJD-OBS to %.6f from JEPOCH", *wcsmjd);
-@@ -362,25 +359,27 @@ int datfix(struct wcsprm *wcs)
++	  if (status == FIXERR_NO_CHANGE) status = FIXERR_SUCCESS;
+ 
+         } else if (!undefined(wcs->bepoch)) {
            *wcsmjd = mjd1900 + (wcs->bepoch - 1900.0)*dty;
            sprintf(newline(&cp), "Set MJD-OBS to %.6f from BEPOCH", *wcsmjd);
++	  if (status == FIXERR_NO_CHANGE) status = FIXERR_SUCCESS;
          }
-+
-+	if (status == FIXERR_NO_CHANGE) status = FIXERR_SUCCESS;
        }
  
        if (undefined(*wcsmjd)) {
@@ -27701,6 +32192,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
        } else {
 -        /* Calendar date from MJD, with allowance for MJD < 0. */
 +        // Calendar date from MJD, with allowance for MJD < 0.
++        double mjd[2], t;
          if (i == 0) {
 -          /* MJDREF is already split into integer and fractional parts. */
 +          // MJDREF is already split into integer and fractional parts.
@@ -27719,7 +32211,17 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
            mjd[0] = floor(*wcsmjd);
            mjd[1] = *wcsmjd - mjd[0];
          }
-@@ -395,7 +394,7 @@ int datfix(struct wcsprm *wcs)
+ 
+-        jd = 2400001 + (int)mjd[0];
++        int jd = 2400001 + (int)mjd[0];
+ 
+-        n4 =  4*(jd + ((2*((4*jd - 17918)/146097)*3)/4 + 1)/2 - 37);
+-        dd = 10*(((n4-237)%1461)/4) + 5;
++        int n4 =  4*(jd + ((2*((4*jd - 17918)/146097)*3)/4 + 1)/2 - 37);
++        int dd = 10*(((n4-237)%1461)/4) + 5;
+ 
+         year  = n4/1461 - 4712;
+         month = (2 + dd/306)%12 + 1;
          day   = (dd%306)/10 + 1;
          sprintf(date, "%.4d-%.2d-%.2d", year, month, day);
  
@@ -27728,7 +32230,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
          if (0.0 < (t = mjd[1])) {
            t *= 24.0;
            hour = (int)t;
-@@ -403,7 +402,7 @@ int datfix(struct wcsprm *wcs)
+@@ -403,15 +402,15 @@ int datfix(struct wcsprm *wcs)
            minute = (int)t;
            sec    = 60.0 * (t - minute);
  
@@ -27737,8 +32239,9 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
            dd = 60000*(60*hour + minute) + (int)(1000*(sec+0.0005));
            hour = dd / 3600000;
            dd -= 3600000 * hour;
-@@ -411,7 +410,7 @@ int datfix(struct wcsprm *wcs)
-           msec = dd - 60000 * minute;
+           minute = dd / 60000;
+-          msec = dd - 60000 * minute;
++          int msec = dd - 60000 * minute;
            sprintf(date+10, "T%.2d:%.2d:%.2d", hour, minute, msec/1000);
  
 -          /* Write fractions of a second only if non-zero. */
@@ -27809,7 +32312,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
            status = FIXERR_BAD_PARAM;
            sprintf(newline(&cp), "Invalid DATE%s format '%s'", dateid, date);
            continue;
-@@ -512,11 +511,11 @@ int datfix(struct wcsprm *wcs)
+@@ -512,17 +511,18 @@ int datfix(struct wcsprm *wcs)
  
          if (year < 100) year += 1900;
  
@@ -27820,10 +32323,18 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
  
 -      /* Compute MJD. */
 +      // Compute MJD.
++      double mjd[2];
        mjd[0] = (double)((1461*(year - (12-month)/10 + 4712))/4
                 + (306*((month+9)%12) + 5)/10
                 - (3*((year - (12-month)/10 + 4900)/100))/4
-@@ -534,8 +533,10 @@ int datfix(struct wcsprm *wcs)
+                + day - 2399904);
+       mjd[1] = (hour + (minute + sec/60.0)/60.0)/24.0;
+-      mjdsum = mjd[0] + mjd[1];
++      double mjdsum = mjd[0] + mjd[1];
+ 
+       if (undefined(*wcsmjd)) {
+         if (i == 0) {
+@@ -534,8 +534,11 @@ int datfix(struct wcsprm *wcs)
          sprintf(newline(&cp), "Set MJD%s to %.6f from DATE%s", dateid,
            mjdsum, dateid);
  
@@ -27832,16 +32343,18 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
        } else {
 -        /* Check for consistency. */
 +        // Check for consistency.
++        double mjdtmp;
          if (i == 0) {
            mjdtmp = wcsmjd[0] + wcsmjd[1];
          } else {
-@@ -552,21 +553,21 @@ int datfix(struct wcsprm *wcs)
+@@ -552,21 +555,21 @@ int datfix(struct wcsprm *wcs)
  
        if (i == 1) {
          if (!undefined(wcs->jepoch)) {
 -          /* Check consistency of JEPOCH. */
+-          jepoch = 2000.0 + (*wcsmjd - mjd2000) / djy;
 +          // Check consistency of JEPOCH.
-           jepoch = 2000.0 + (*wcsmjd - mjd2000) / djy;
++          double jepoch = 2000.0 + (*wcsmjd - mjd2000) / djy;
  
            if (0.000002 < fabs(jepoch - wcs->jepoch)) {
 -            /* Informational only, no error. */
@@ -27852,8 +32365,9 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
  
          if (!undefined(wcs->bepoch)) {
 -          /* Check consistency of BEPOCH. */
+-          bepoch = 1900.0 + (*wcsmjd - mjd1900) / dty;
 +          // Check consistency of BEPOCH.
-           bepoch = 1900.0 + (*wcsmjd - mjd1900) / dty;
++          double bepoch = 1900.0 + (*wcsmjd - mjd1900) / dty;
  
            if (0.000002 < fabs(bepoch - wcs->bepoch)) {
 -            /* Informational only, no error. */
@@ -27861,7 +32375,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
              sprintf(newline(&cp), "BEPOCH is inconsistent with DATE-OBS");
            }
          }
-@@ -582,7 +583,7 @@ int datfix(struct wcsprm *wcs)
+@@ -582,7 +585,7 @@ int datfix(struct wcsprm *wcs)
            orig_date, date);
        }
  
@@ -27870,7 +32384,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
      }
    }
  
-@@ -593,14 +594,14 @@ int datfix(struct wcsprm *wcs)
+@@ -593,37 +596,33 @@ int datfix(struct wcsprm *wcs)
    return status;
  }
  
@@ -27883,20 +32397,32 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
    static const char *function = "obsfix";
  
 -  /* IAU(1976) ellipsoid (as prescribed by WCS Paper VII). */
+-  const double a = 6378140.0, f = 1.0 / 298.2577;
 +  // IAU(1976) ellipsoid (as prescribed by WCS Paper VII).
-   const double a = 6378140.0, f = 1.0 / 298.2577;
++  const double a  = 6378140.0;
++  const double f  = 1.0 / 298.2577;
    const double e2 = (2.0 - f)*f;
  
-@@ -614,7 +615,7 @@ int obsfix(int ctrl, struct wcsprm *wcs)
+-  char   *cp, infomsg[256];
+-  int    havelbh = 7, havexyz = 7, i, status;
+-  size_t k;
+-  double coslat, coslng, d, hgt, lat, lng, n, r2, rho, sinlat, sinlng, x, y,
+-         z, zeta;
+-  struct wcserr **err;
+-
    if (wcs == 0x0) return FIXERR_NULL_POINTER;
-   err = &(wcs->err);
+-  err = &(wcs->err);
++  struct wcserr **err = &(wcs->err);
  
 -  /* Set masks for checking partially-defined coordinate triplets. */
 +  // Set masks for checking partially-defined coordinate triplets.
++  int havexyz = 7;
    havexyz -= 1*undefined(wcs->obsgeo[0]);
    havexyz -= 2*undefined(wcs->obsgeo[1]);
    havexyz -= 4*undefined(wcs->obsgeo[2]);
-@@ -623,7 +624,7 @@ int obsfix(int ctrl, struct wcsprm *wcs)
++  int havelbh = 7;
+   havelbh -= 1*undefined(wcs->obsgeo[3]);
+   havelbh -= 2*undefined(wcs->obsgeo[4]);
    havelbh -= 4*undefined(wcs->obsgeo[5]);
  
    if (ctrl == 2) {
@@ -27905,27 +32431,44 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
      if (0 < havexyz && havexyz < 7) {
        return wcserr_set(WCSERR_SET(FIXERR_BAD_PARAM),
          "Partially undefined Cartesian coordinate triplet");
-@@ -648,7 +649,7 @@ int obsfix(int ctrl, struct wcsprm *wcs)
-   status = FIXERR_NO_CHANGE;
+@@ -644,24 +643,29 @@ int obsfix(int ctrl, struct wcsprm *wcs)
+   }
  
+ 
++  char infomsg[256];
+   infomsg[0] = '\0';
+-  status = FIXERR_NO_CHANGE;
+ 
++  int status = FIXERR_NO_CHANGE;
++
++  size_t k;
++  double x, y, z;
    if (havelbh == 7) {
 -    /* Compute (x,y,z) from (lng,lat,hgt). */
 +    // Compute (x,y,z) from (lng,lat,hgt).
++    double coslat, coslng, sinlat, sinlng;
      sincosd(wcs->obsgeo[3], &sinlng, &coslng);
      sincosd(wcs->obsgeo[4], &sinlat, &coslat);
-     n = a / sqrt(1.0 - e2*sinlat*sinlat);
-@@ -659,8 +660,8 @@ int obsfix(int ctrl, struct wcsprm *wcs)
+-    n = a / sqrt(1.0 - e2*sinlat*sinlat);
+-    rho = n + wcs->obsgeo[5];
++    double n = a / sqrt(1.0 - e2*sinlat*sinlat);
++    double rho = n + wcs->obsgeo[5];
+ 
+     x = rho*coslng*coslat;
+     y = rho*sinlng*coslat;
      z = (rho - n*e2)*sinlat;
  
      if (havexyz < 7) {
 -      /* One or more of the Cartesian elements was undefined. */
 -      status = 0;
+-      cp = infomsg;
 +      // One or more of the Cartesian elements was undefined.
 +      status = FIXERR_SUCCESS;
-       cp = infomsg;
++      char *cp = infomsg;
  
        if (ctrl == 1 || !(havexyz & 1)) {
-@@ -695,19 +696,19 @@ int obsfix(int ctrl, struct wcsprm *wcs)
+         wcs->obsgeo[0] = x;
+@@ -695,21 +699,22 @@ int obsfix(int ctrl, struct wcsprm *wcs)
        wcserr_set(WCSERR_SET(FIXERR_OBSGEO_FIX), infomsg);
  
        if (havexyz == 0) {
@@ -27941,25 +32484,41 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
      x = wcs->obsgeo[0];
      y = wcs->obsgeo[1];
      z = wcs->obsgeo[2];
-     r2 = x*x + y*y;
+-    r2 = x*x + y*y;
++    double r2 = x*x + y*y;
  
 -    /* Iterate over the value of zeta. */
+-    zeta = z;
+-    for (i = 0; i < 4; i++) {
 +    // Iterate over the value of zeta.
-     zeta = z;
-     for (i = 0; i < 4; i++) {
++    double coslat, coslng, sinlat, sinlng;
++    double n, rho, zeta = z;
++    for (int i = 0; i < 4; i++) {
        rho = sqrt(r2 + zeta*zeta);
-@@ -722,8 +723,8 @@ int obsfix(int ctrl, struct wcsprm *wcs)
-     hgt = rho - n;
+       sinlat = zeta / rho;
+       n = a / sqrt(1.0 - e2*sinlat*sinlat);
+@@ -717,14 +722,14 @@ int obsfix(int ctrl, struct wcsprm *wcs)
+       zeta = z / (1.0 - n*e2/rho);
+     }
+ 
+-    lng = atan2d(y, x);
+-    lat = asind(sinlat);
+-    hgt = rho - n;
++    double lng = atan2d(y, x);
++    double lat = asind(sinlat);
++    double hgt = rho - n;
  
      if (havelbh < 7) {
 -      /* One or more of the Geodetic elements was undefined. */
 -      status = 0;
+-      cp = infomsg;
 +      // One or more of the Geodetic elements was undefined.
 +      status = FIXERR_SUCCESS;
-       cp = infomsg;
++      char *cp = infomsg;
  
        if (ctrl == 1 || !(havelbh & 1)) {
-@@ -757,12 +758,12 @@ int obsfix(int ctrl, struct wcsprm *wcs)
+         wcs->obsgeo[3] = lng;
+@@ -757,12 +762,12 @@ int obsfix(int ctrl, struct wcsprm *wcs)
        wcserr_set(WCSERR_SET(FIXERR_OBSGEO_FIX), infomsg);
  
        if (havelbh == 0) {
@@ -27974,16 +32533,18 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
      sincosd(wcs->obsgeo[3], &sinlng, &coslng);
      sincosd(wcs->obsgeo[4], &sinlat, &coslat);
      n = a / sqrt(1.0 - e2*sinlat*sinlat);
-@@ -778,7 +779,7 @@ int obsfix(int ctrl, struct wcsprm *wcs)
+@@ -778,8 +783,8 @@ int obsfix(int ctrl, struct wcsprm *wcs)
    }
  
  
 -  /* Check consistency. */
+-  r2 = 0.0;
 +  // Check consistency.
-   r2 = 0.0;
++  double d, r2 = 0.0;
    d = wcs->obsgeo[0] - x;
    r2 += d*d;
-@@ -797,7 +798,7 @@ int obsfix(int ctrl, struct wcsprm *wcs)
+   d = wcs->obsgeo[1] - y;
+@@ -797,30 +802,30 @@ int obsfix(int ctrl, struct wcsprm *wcs)
  }
  
  
@@ -27992,13 +32553,46 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
  
  int unitfix(int ctrl, struct wcsprm *wcs)
  
-@@ -829,18 +830,18 @@ int unitfix(int ctrl, struct wcsprm *wcs
+ {
+   const char *function = "unitfix";
+ 
+-  char   orig_unit[72], msg[512], msgtmp[192];
+-  int    i, result, status = FIXERR_NO_CHANGE;
+-  size_t msglen;
+-  struct wcserr **err;
+-
+   if (wcs == 0x0) return FIXERR_NULL_POINTER;
+-  err = &(wcs->err);
++  struct wcserr **err = &(wcs->err);
+ 
++  int status = FIXERR_NO_CHANGE;
++
++  char msg[512];
+   strncpy(msg, "Changed units:", 512);
+ 
+-  for (i = 0; i < wcs->naxis; i++) {
++  for (int i = 0; i < wcs->naxis; i++) {
++    char orig_unit[72];
+     strncpy(orig_unit, wcs->cunit[i], 71);
+-    result = wcsutrne(ctrl, wcs->cunit[i], &(wcs->err));
++    int result = wcsutrne(ctrl, wcs->cunit[i], &(wcs->err));
+     if (result == 0 || result == 12) {
+-      msglen = strlen(msg);
++      size_t msglen = strlen(msg);
+       if (msglen < 511) {
+         wcsutil_null_fill(72, orig_unit);
++        char msgtmp[192];
+         sprintf(msgtmp, "\n  '%s' -> '%s',", orig_unit, wcs->cunit[i]);
+         strncpy(msg+msglen, msgtmp, 511-msglen);
+         status = FIXERR_UNITS_ALIAS;
+@@ -829,52 +834,49 @@ int unitfix(int ctrl, struct wcsprm *wcs
    }
  
    if (status == FIXERR_UNITS_ALIAS) {
 -    /* Chop off the trailing ", ". */
+-    msglen = strlen(msg) - 2;
 +    // Chop off the trailing ", ".
-     msglen = strlen(msg) - 2;
++    size_t msglen = strlen(msg) - 2;
      msg[msglen] = '\0';
      wcserr_set(WCSERR_SET(FIXERR_UNITS_ALIAS), msg);
  
@@ -28014,15 +32608,26 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
  
  int spcfix(struct wcsprm *wcs)
  
-@@ -855,26 +856,26 @@ int spcfix(struct wcsprm *wcs)
-   err = &(wcs->err);
+ {
+   static const char *function = "spcfix";
  
-   for (i = 0; i < wcs->naxis; i++) {
+-  char ctype[9], specsys[9];
+-  int  i, status;
+-  struct wcserr **err;
+-
+   if (wcs == 0x0) return FIXERR_NULL_POINTER;
+-  err = &(wcs->err);
++  struct wcserr **err = &(wcs->err);
+ 
+-  for (i = 0; i < wcs->naxis; i++) {
 -    /* Translate an AIPS-convention spectral type if present. */
-+    // Translate an AIPS-convention spectral type if present.
-     status = spcaips(wcs->ctype[i], wcs->velref, ctype, specsys);
+-    status = spcaips(wcs->ctype[i], wcs->velref, ctype, specsys);
 -    if (status == 0) {
 -      /* An AIPS type was found but it may match what we already have. */
++  for (int i = 0; i < wcs->naxis; i++) {
++    // Translate an AIPS-convention spectral type if present.
++    char ctype[9], specsys[9];
++    int status = spcaips(wcs->ctype[i], wcs->velref, ctype, specsys);
 +    if (status == FIXERR_SUCCESS) {
 +      // An AIPS type was found but it may match what we already have.
        status = FIXERR_NO_CHANGE;
@@ -28050,7 +32655,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
            wcserr_set(WCSERR_SET(FIXERR_SPC_UPDATE),
              "Changed CTYPE%d from '%s' to '%s', and SPECSYS to '%s' "
              "(VELREF=%d)", i+1, wcs->ctype[i], ctype, wcs->specsys,
-@@ -883,23 +884,23 @@ int spcfix(struct wcsprm *wcs)
+@@ -883,23 +885,23 @@ int spcfix(struct wcsprm *wcs)
            wcserr_set(WCSERR_SET(FIXERR_SPC_UPDATE),
              "Changed CTYPE%d from '%s' to '%s' (VELREF=%d)", i+1,
              wcs->ctype[i], ctype, wcs->velref);
@@ -28079,7 +32684,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
        return wcserr_set(WCSERR_SET(FIXERR_BAD_PARAM),
          "Invalid parameter value: velref = %d", wcs->velref);
      }
-@@ -908,7 +909,7 @@ int spcfix(struct wcsprm *wcs)
+@@ -908,35 +910,31 @@ int spcfix(struct wcsprm *wcs)
    return FIXERR_NO_CHANGE;
  }
  
@@ -28088,12 +32693,21 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
  
  int celfix(struct wcsprm *wcs)
  
-@@ -923,20 +924,20 @@ int celfix(struct wcsprm *wcs)
+ {
+   static const char *function = "celfix";
+ 
+-  int k, status;
+-  struct celprm *wcscel = &(wcs->cel);
+-  struct prjprm *wcsprj = &(wcscel->prj);
+-  struct wcserr **err;
+-
    if (wcs == 0x0) return FIXERR_NULL_POINTER;
-   err = &(wcs->err);
+-  err = &(wcs->err);
++  struct wcserr **err = &(wcs->err);
  
 -  /* Initialize if required. */
 +  // Initialize if required.
++  int status;
    if (wcs->flag != WCSSET) {
      if ((status = wcsset(wcs))) return fix_wcserr[status];
    }
@@ -28113,7 +32727,33 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
          if (wcs->m_flag == WCSSET && wcs->pv == wcs->m_pv) {
            if (!(wcs->pv = calloc(wcs->npv+2, sizeof(struct pvcard)))) {
              wcs->pv = wcs->m_pv;
-@@ -975,16 +976,16 @@ int celfix(struct wcsprm *wcs)
+@@ -946,7 +944,7 @@ int celfix(struct wcsprm *wcs)
+           wcs->npvmax = wcs->npv + 2;
+           wcs->m_flag = WCSSET;
+ 
+-          for (k = 0; k < wcs->npv; k++) {
++          for (int k = 0; k < wcs->npv; k++) {
+             wcs->pv[k] = wcs->m_pv[k];
+           }
+ 
+@@ -958,6 +956,8 @@ int celfix(struct wcsprm *wcs)
+         }
+       }
+ 
++      struct celprm *wcscel = &(wcs->cel);
++      struct prjprm *wcsprj = &(wcscel->prj);
+       wcs->pv[wcs->npv].i = wcs->lat + 1;
+       wcs->pv[wcs->npv].m = 1;
+       wcs->pv[wcs->npv].value = wcsprj->pv[1];
+@@ -968,23 +968,23 @@ int celfix(struct wcsprm *wcs)
+       wcs->pv[wcs->npv].value = wcsprj->pv[2];
+       (wcs->npv)++;
+ 
+-      return 0;
++      return FIXERR_SUCCESS;
+ 
+     } else if (strcmp(wcs->ctype[wcs->lat]+5, "GLS") == 0) {
+       strcpy(wcs->ctype[wcs->lng]+5, "SFL");
        strcpy(wcs->ctype[wcs->lat]+5, "SFL");
  
        if (wcs->crval[wcs->lng] != 0.0 || wcs->crval[wcs->lat] != 0.0) {
@@ -28139,7 +32779,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
            if (wcs->m_flag == WCSSET && wcs->pv == wcs->m_pv) {
              if (!(wcs->pv = calloc(wcs->npv+3, sizeof(struct pvcard)))) {
                wcs->pv = wcs->m_pv;
-@@ -1011,7 +1012,7 @@ int celfix(struct wcsprm *wcs)
+@@ -994,7 +994,7 @@ int celfix(struct wcsprm *wcs)
+             wcs->npvmax = wcs->npv + 3;
+             wcs->m_flag = WCSSET;
+ 
+-            for (k = 0; k < wcs->npv; k++) {
++            for (int k = 0; k < wcs->npv; k++) {
+               wcs->pv[k] = wcs->m_pv[k];
+             }
+ 
+@@ -1011,7 +1011,7 @@ int celfix(struct wcsprm *wcs)
          wcs->pv[wcs->npv].value = 1.0;
          (wcs->npv)++;
  
@@ -28148,7 +32797,15 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
          wcs->pv[wcs->npv].i = wcs->lng + 1;
          wcs->pv[wcs->npv].m = 1;
          wcs->pv[wcs->npv].value = 0.0;
-@@ -1030,7 +1031,7 @@ int celfix(struct wcsprm *wcs)
+@@ -1023,55 +1023,54 @@ int celfix(struct wcsprm *wcs)
+         (wcs->npv)++;
+       }
+ 
+-      return 0;
++      return FIXERR_SUCCESS;
+     }
+   }
+ 
    return FIXERR_NO_CHANGE;
  }
  
@@ -28157,12 +32814,23 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
  
  int cylfix(const int naxis[], struct wcsprm *wcs)
  
-@@ -1047,17 +1048,17 @@ int cylfix(const int naxis[], struct wcs
+ {
+   static const char *function = "cylfix";
+ 
+-  unsigned short icnr, indx[NMAX], ncnr;
+-  int    j, k, stat[4], status;
+-  double img[4][NMAX], lat, lng, phi[4], phi0, phimax, phimin, pix[4][NMAX],
+-         *pixj, theta[4], theta0, world[4][NMAX], x, y;
+-  struct wcserr **err;
+-
+   if (naxis == 0x0) return FIXERR_NO_CHANGE;
    if (wcs == 0x0) return FIXERR_NULL_POINTER;
-   err = &(wcs->err);
+-  err = &(wcs->err);
++  struct wcserr **err = &(wcs->err);
  
 -  /* Initialize if required. */
 +  // Initialize if required.
++  int status;
    if (wcs->flag != WCSSET) {
      if ((status = wcsset(wcs))) return fix_wcserr[status];
    }
@@ -28174,20 +32842,47 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
  
  
 -  /* Compute the native longitude in each corner of the image. */
+-  ncnr = 1 << wcs->naxis;
 +  // Compute the native longitude in each corner of the image.
-   ncnr = 1 << wcs->naxis;
++  unsigned short ncnr = 1 << wcs->naxis;
  
-   for (k = 0; k < NMAX; k++) {
-@@ -1067,7 +1068,7 @@ int cylfix(const int naxis[], struct wcs
-   phimin =  1.0e99;
-   phimax = -1.0e99;
-   for (icnr = 0; icnr < ncnr;) {
+-  for (k = 0; k < NMAX; k++) {
++  unsigned short indx[NMAX];
++  for (int k = 0; k < NMAX; k++) {
+     indx[k] = 1 << k;
+   }
+ 
+-  phimin =  1.0e99;
+-  phimax = -1.0e99;
+-  for (icnr = 0; icnr < ncnr;) {
 -    /* Do four corners at a time. */
+-    for (j = 0; j < 4; j++, icnr++) {
+-      pixj = pix[j];
++  int    stat[4];
++  double img[4][NMAX], phi[4], pix[4][NMAX], theta[4], world[4][NMAX];
++
++  double phimin =  1.0e99;
++  double phimax = -1.0e99;
++  for (unsigned short icnr = 0; icnr < ncnr;) {
 +    // Do four corners at a time.
-     for (j = 0; j < 4; j++, icnr++) {
-       pixj = pix[j];
++    for (int j = 0; j < 4; j++, icnr++) {
++      double *pixj = pix[j];
  
-@@ -1091,11 +1092,11 @@ int cylfix(const int naxis[], struct wcs
+-      for (k = 0; k < wcs->naxis; k++) {
++      for (int k = 0; k < wcs->naxis; k++) {
+         if (icnr & indx[k]) {
+           *(pixj++) = naxis[k] + 0.5;
+         } else {
+@@ -1082,7 +1081,7 @@ int cylfix(const int naxis[], struct wcs
+ 
+     if (!(status = wcsp2s(wcs, 4, NMAX, pix[0], img[0], phi, theta, world[0],
+                           stat))) {
+-      for (j = 0; j < 4; j++) {
++      for (int j = 0; j < 4; j++) {
+         if (phi[j] < phimin) phimin = phi[j];
+         if (phi[j] > phimax) phimax = phi[j];
+       }
+@@ -1091,14 +1090,15 @@ int cylfix(const int naxis[], struct wcs
  
    if (phimin > phimax) return fix_wcserr[status];
  
@@ -28197,11 +32892,26 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
  
  
 -  /* Compute the new reference pixel coordinates. */
+-  phi0 = (phimin + phimax) / 2.0;
+-  theta0 = 0.0;
 +  // Compute the new reference pixel coordinates.
-   phi0 = (phimin + phimax) / 2.0;
-   theta0 = 0.0;
++  double phi0 = (phimin + phimax) / 2.0;
++  double theta0 = 0.0;
  
-@@ -1120,13 +1121,13 @@ int cylfix(const int naxis[], struct wcs
++  double x, y;
+   if ((status = prjs2x(&(wcs->cel.prj), 1, 1, 1, 1, &phi0, &theta0, &x, &y,
+                        stat))) {
+     if (status == PRJERR_BAD_PARAM) {
+@@ -1109,7 +1109,7 @@ int cylfix(const int naxis[], struct wcs
+     return wcserr_set(WCSFIX_ERRMSG(status));
+   }
+ 
+-  for (k = 0; k < wcs->naxis; k++) {
++  for (int k = 0; k < wcs->naxis; k++) {
+     img[0][k] = 0.0;
+   }
+   img[0][wcs->lng] = x;
+@@ -1120,15 +1120,15 @@ int cylfix(const int naxis[], struct wcs
    }
  
  
@@ -28213,20 +32923,382 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.c
    }
  
 -  /* Compute native coordinates of the celestial pole. */
+-  lng =  0.0;
+-  lat = 90.0;
 +  // Compute native coordinates of the celestial pole.
-   lng =  0.0;
-   lat = 90.0;
++  double lng =  0.0;
++  double lat = 90.0;
    (void)sphs2x(wcs->cel.euler, 1, 1, 1, 1, &lng, &lat, phi, theta);
-Index: astropy-4.2/cextern/wcslib/C/wcsfix.h
+ 
+   wcs->crpix[wcs->lng] = pix[0][wcs->lng];
+@@ -1139,3 +1139,357 @@ int cylfix(const int naxis[], struct wcs
+ 
+   return wcsset(wcs);
+ }
++
++//----------------------------------------------------------------------------
++
++// Helper function used only by wcspcx().
++static int unscramble(int n, int mapto[], int step, int type, void *vptr);
++
++int wcspcx(
++  struct wcsprm *wcs,
++  int dopc,
++  int permute,
++  double rotn[2])
++
++{
++  static const char *function = "wcspcx";
++
++  // Initialize if required.
++  if (wcs == 0x0) return FIXERR_NULL_POINTER;
++  struct wcserr **err = &(wcs->err);
++
++  int status;
++  if (wcs->flag != WCSSET) {
++    if ((status = wcsset(wcs))) return fix_wcserr[status];
++  }
++
++  // Check for CDi_j usage.
++  double *wcscd = wcs->cd;
++  if ((wcs->altlin & 1) || !(wcs->altlin & 2)) {
++    if ((wcs->altlin & 1) && dopc == 1) {
++      // Recompose PCi_j + CDELTi.
++      wcscd = wcs->pc;
++    } else {
++      return wcserr_set(WCSERR_SET(FIXERR_BAD_PARAM),
++        "CDi_j is not used in this coordinate representation");
++    }
++  }
++
++  // Check for sequent distortions.
++  if (wcs->lin.disseq) {
++    return wcserr_set(WCSERR_SET(FIXERR_BAD_COORD_TRANS),
++      "Cannot handle coordinate descriptions containing sequent distortions");
++  }
++
++
++  // Allocate memory in bulk for two nxn matrices.
++  int naxis = wcs->naxis;
++  double *mem;
++  if ((mem = calloc(2*naxis*naxis, sizeof(double))) == 0x0) {
++    return wcserr_set(WCSFIX_ERRMSG(FIXERR_MEMORY));
++  }
++
++  double *mat = mem;
++  double *inv = mem + naxis*naxis;
++
++  // Construct the transpose of CDi_j with each element squared.
++  double *matij = mat;
++  for (int i = 0; i < naxis; i++) {
++    double *cdji = wcscd + i;
++    for (int j = 0; j < naxis; j++) {
++      *(matij++) = (*cdji) * (*cdji);
++      cdji += naxis;
++    }
++  }
++
++  // Invert the matrix.
++  if ((status = matinv(naxis, mat, inv))) {
++    return wcserr_set(WCSERR_SET(FIXERR_SINGULAR_MTX),
++      "No solution for CDi_j matrix decomposition");
++  }
++
++  // Apply scaling.
++  double *invij = inv;
++  double *pcij = wcs->pc;
++  double *cdij = wcscd;
++  for (int i = 0; i < naxis; i++) {
++    double scl = 0.0;
++    for (int j = 0; j < naxis; j++) {
++      scl += *(invij++);
++    }
++
++    scl = sqrt(scl);
++    wcs->cdelt[i] /= scl;
++
++    for (int j = 0; j < naxis; j++) {
++      *(pcij++) = *(cdij++) * scl;
++    }
++  }
++
++  // mapto[i] records where row i of PCi_j should move to.
++  int *mapto;
++  if ((mapto = (int*)malloc(naxis * sizeof(int))) == 0x0) {
++    free(mem);
++    return wcserr_set(WCSFIX_ERRMSG(FIXERR_MEMORY));
++  }
++  for (int i = 0; i < naxis; i++) {
++    mapto[i] = -1;
++  }
++
++  // Ensure that latitude always follows longitude.
++  if (wcs->lng >= 0 && wcs->lat >= 0) {
++    double *pci = wcs->pc + naxis*wcs->lng;
++
++    // Take the first non-zero element in the row.
++    for (int j = 0; j < naxis; j++) {
++      if (fabs(pci[j]) != 0.0) {
++        mapto[wcs->lng] = j;
++        break;
++      }
++    }
++
++    if (mapto[wcs->lng] == naxis-1) {
++      mapto[wcs->lng]--;
++    }
++
++    mapto[wcs->lat] = mapto[wcs->lng] + 1;
++  }
++
++  // Fill in the rest of the row permutation map.
++  for (int j = 0; j < naxis; j++) {
++    // Column j.
++    double *pcij = wcs->pc + j;
++    double colmax = 0.0;
++
++    // Look down the column to find the absolute maximum element.
++    for (int i = 0; i < naxis; i++, pcij += naxis) {
++      if (!(mapto[i] < 0)) {
++        // This row is already mapped.
++        continue;
++      }
++
++      if (fabs(*pcij) > colmax) {
++        mapto[i] = j;
++        colmax = fabs(*pcij);
++      }
++    }
++  }
++
++  // Fix the sign of CDELTi.  Celestial axes are special, otherwise diagonal
++  // elements of the correctly permuted matrix should be positive.
++  for (int i = 0; i < naxis; i++) {
++    int chsgn;
++    double *pci = wcs->pc + naxis*i;
++
++    // Celestial axes are special.
++    if (i == wcs->lng) {
++      // Longitude axis - force CDELTi < 0.0.
++      chsgn = (wcs->cdelt[i] > 0.0);
++    } else if (i == wcs->lat) {
++      // Latitude axis - force CDELTi > 0.0.
++      chsgn = (wcs->cdelt[i] < 0.0);
++    } else {
++      chsgn = (pci[mapto[i]] < 0.0);
++    }
++
++    if (chsgn) {
++      wcs->cdelt[i] = -wcs->cdelt[i];
++
++      for (int j = 0; j < naxis; j++) {
++        // Test needed to prevent negative zeros.
++        if (pci[j] != 0.0) {
++          pci[j] = -pci[j];
++        }
++      }
++    }
++  }
++
++  free(mem);
++
++  // Setting bit 3 in wcsprm::altlin stops wcsset() from reconstructing
++  // PCi_j and CDELTi from CDi_j.
++  wcs->altlin |= 8;
++
++
++  // Compute rotation angle of each basis vector of the celestial axes.
++  if (rotn) {
++    if (wcs->lng < 0 || wcs->lat < 0) {
++      // No celestial axes.
++      rotn[0] = 0.0;
++      rotn[1] = 0.0;
++
++    } else {
++      double x, y;
++      x =  wcs->pc[naxis*wcs->lng + mapto[wcs->lng]];
++      y =  wcs->pc[naxis*wcs->lat + mapto[wcs->lng]];
++      rotn[0] = atan2d(y, x);
++
++      y = -wcs->pc[naxis*wcs->lng + mapto[wcs->lat]];
++      x =  wcs->pc[naxis*wcs->lat + mapto[wcs->lat]];
++      rotn[1] = atan2d(y, x);
++    }
++  }
++
++
++  // Permute rows?
++  if (permute) {
++    // Check whether there's anything to unscramble.
++    int scrambled = 0;
++    for (int i = 0; i < naxis; i++) {
++      if (mapto[i] != i) {
++        scrambled = 1;
++        break;
++      }
++    }
++
++    if (scrambled) {
++      for (int i = 0; i < naxis; i++) {
++        // Do columns of the PCi_ja matrix.
++        if (unscramble(naxis, mapto, naxis, 1, wcs->pc + i)) {
++          free(mapto);
++          return wcserr_set(WCSFIX_ERRMSG(FIXERR_MEMORY));
++        }
++      }
++
++      if (unscramble(naxis, mapto, 1, 1, wcs->cdelt) ||
++          unscramble(naxis, mapto, 1, 1, wcs->crval) ||
++          unscramble(naxis, mapto, 1, 2, wcs->cunit) ||
++          unscramble(naxis, mapto, 1, 2, wcs->ctype)) {
++        free(mapto);
++        return wcserr_set(WCSFIX_ERRMSG(FIXERR_MEMORY));
++      }
++
++      for (int ipv = 0; ipv < wcs->npv; ipv++) {
++        // Noting that PVi_ma axis numbers are 1-relative.
++        int i = wcs->pv[ipv].i - 1;
++        wcs->pv[ipv].i = mapto[i] + 1;
++      }
++
++      for (int ips = 0; ips < wcs->nps; ips++) {
++        // Noting that PSi_ma axis numbers are 1-relative.
++        int i = wcs->ps[ips].i - 1;
++        wcs->ps[ips].i = mapto[i] + 1;
++      }
++
++      if (wcs->altlin & 2) {
++        for (int i = 0; i < naxis; i++) {
++          // Do columns of the CDi_ja matrix.
++          if (unscramble(naxis, mapto, naxis, 1, wcs->cd + i)) {
++            free(mapto);
++            return wcserr_set(WCSFIX_ERRMSG(FIXERR_MEMORY));
++          }
++        }
++      }
++
++      if (wcs->altlin & 4) {
++        if (unscramble(naxis, mapto, 1, 1, wcs->crota)) {
++          free(mapto);
++          return wcserr_set(WCSFIX_ERRMSG(FIXERR_MEMORY));
++        }
++      }
++
++      if (unscramble(naxis, mapto, 1, 3, wcs->colax) ||
++          unscramble(naxis, mapto, 1, 2, wcs->cname) ||
++          unscramble(naxis, mapto, 1, 1, wcs->crder) ||
++          unscramble(naxis, mapto, 1, 1, wcs->csyer) ||
++          unscramble(naxis, mapto, 1, 1, wcs->czphs) ||
++          unscramble(naxis, mapto, 1, 1, wcs->cperi)) {
++        free(mapto);
++        return wcserr_set(WCSFIX_ERRMSG(FIXERR_MEMORY));
++      }
++
++      // Coordinate lookup tables.
++      for (int itab = 0; itab < wcs->ntab; itab++) {
++        for (int m = 0; m < wcs->tab[itab].M; m++) {
++          int i = wcs->tab[itab].map[m];
++          wcs->tab[itab].map[m] = mapto[i];
++        }
++      }
++
++      for (int iwtb = 0; iwtb < wcs->nwtb; iwtb++) {
++        int i = wcs->wtb[iwtb].i;
++        wcs->wtb[iwtb].i = mapto[i];
++      }
++
++      // Distortions?  No. Prior distortions operate on pixel coordinates and
++      // therefore are not permuted, and sequent distortions are not handled.
++    }
++  }
++
++  free(mapto);
++
++  // Reset the struct.
++  if ((status = wcsset(wcs))) return fix_wcserr[status];
++
++  return FIXERR_SUCCESS;
++}
++
++
++int unscramble(
++  int n,
++  int mapto[],
++  int step,
++  int type,
++  void *vptr)
++
++{
++  if (step == 0) step = 1;
++
++  if (type == 1) {
++    double *dval = (double *)vptr;
++
++    double *dtmp;
++    if ((dtmp = (double *)malloc(n * sizeof(double))) == 0x0) {
++      return 1;
++    }
++
++    for (int i = 0; i < n; i++) {
++      dtmp[mapto[i]] = dval[i*step];
++    }
++
++    for (int i = 0; i < n; i++) {
++      dval[i*step] = dtmp[i];
++    }
++
++    free(dtmp);
++
++  } else if (type == 2) {
++    char (*cval)[72] = (char (*)[72])vptr;
++
++    int row_size = 72 * sizeof(char);
++    char *ctmp;
++    if ((ctmp = (char *)malloc(n * row_size)) == 0x0) {
++      return 1;
++    }
++
++    for (int i = 0; i < n; i++) {
++      memcpy(ctmp + row_size * mapto[i], cval[i], 72);
++    }
++
++    for (int i = 0; i < n; i++) {
++      memcpy(cval[i], ctmp + row_size * i, 72);
++    }
++
++    free(ctmp);
++
++  } else if (type == 3) {
++    int *ival = (int *)vptr;
++
++    int *itmp;
++    if ((itmp = (int *)malloc(n * sizeof(int))) == 0x0) {
++      return 1;
++    }
++
++    for (int i = 0; i < n; i++) {
++      itmp[mapto[i]] = ival[i];
++    }
++
++    for (int i = 0; i < n; i++) {
++      ival[i] = itmp[i];
++    }
++
++    free(itmp);
++  }
++
++  return 0;
++}
+Index: astropy-4.2.1/cextern/wcslib/C/wcsfix.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcsfix.h
-+++ astropy-4.2/cextern/wcslib/C/wcsfix.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcsfix.h
++++ astropy-4.2.1/cextern/wcslib/C/wcsfix.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -28240,15 +33312,29 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcsfix.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcsfix.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcsfix.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
-@@ -92,18 +89,17 @@
+@@ -57,6 +54,13 @@
+ * consistency of pairs of keyvalues that define the same measure in two
+ * different ways, for example, as a date and an MJD.
+ *
++* A separate routine, wcspcx(), "regularizes" the linear transformation matrix
++* component (PCi_j) of the coordinate transformation to make it more human-
++* readable.  Where a coordinate description was constructed from CDi_j, it
++* decomposes it into PCi_j + CDELTi in a meaningful way.  Optionally, it can
++* also diagonalize the PCi_j matrix (as far as possible), i.e. undo the
++* transposition of axes in the intermediate pixel coordinate system.
++*
+ * Non-standard keyvalues:
+ * -----------------------
+ *   AIPS-convention celestial projection types, NCP and GLS, and spectral
+@@ -92,18 +96,17 @@
  *   header parser supplied with WCSLIB, refer to wcshdr.h.
  *
  * wcsfix() and wcsfixi() apply all of the corrections handled by the following
@@ -28273,7 +33359,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.h
  *
  *   - obsfix(): if only one half of obsgeo[] is set, then derive the other
  *     half from it.  If both halves are set, then check consistency.
-@@ -173,7 +169,7 @@
+@@ -173,11 +176,14 @@
  * cdfix() - Fix erroneously omitted CDi_ja keywords
  * -------------------------------------------------
  * cdfix() sets the diagonal element of the CDi_ja matrix to unity if all
@@ -28282,7 +33368,14 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.h
  * Paper I, if any CDi_ja keywords at all are given in a FITS header then those
  * not given default to zero.  This results in a singular matrix with an
  * intersecting row and column of zeros.
-@@ -192,14 +188,13 @@
+ *
++* cdfix() is expected to be invoked before wcsset(), which will fail if these
++* errors have not been corrected.
++*
+ * Given and returned:
+ *   wcs       struct wcsprm*
+ *                       Coordinate transformation parameters.
+@@ -192,20 +198,22 @@
  * datfix() - Translate DATE-OBS and derive MJD-OBS or vice versa
  * --------------------------------------------------------------
  * datfix() translates the old DATE-OBS date format set in wcsprm::dateobs to
@@ -28304,7 +33397,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.h
  *
  * If neither dateobs nor mjdobs are set, but wcsprm::jepoch (primarily) or
  * wcsprm::bepoch is, then both are derived from it.  If jepoch and/or bepoch
-@@ -222,13 +217,15 @@
+ * are set but disagree with dateobs or mjdobs by more than 0.000002 year
+ * (63.2 seconds), an informative message is produced.
+ *
++* The translations done by datfix() do not affect and are not affected by
++* wcsset().
++*
+ * Given and returned:
+ *   wcs       struct wcsprm*
+ *                       Coordinate transformation parameters.
+@@ -222,13 +230,15 @@
  *                         1: Null wcsprm pointer passed.
  *                         5: Invalid parameter value.
  *
@@ -28325,7 +33427,17 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.h
  *
  *
  * obsfix() - complete the OBSGEO-[XYZLBH] vector of observatory coordinates
-@@ -261,8 +258,10 @@
+@@ -239,6 +249,9 @@
+ * it.  If both triplets are set, then it checks for consistency at the level
+ * of 1 metre.
+ *
++* The operations done by obsfix() do not affect and are not affected by
++* wcsset().
++*
+ * Given:
+ *   ctrl      int       Flag that controls behaviour if one triplet is
+ *                       defined and the other is only partially defined:
+@@ -261,8 +274,10 @@
  *                         1: Null wcsprm pointer passed.
  *                         5: Invalid parameter value.
  *
@@ -28338,7 +33450,17 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.h
  *
  * Notes:
  *   1: While the International Terrestrial Reference System (ITRS) is based
-@@ -332,9 +331,10 @@
+@@ -318,6 +333,9 @@
+ * unitfix() applies wcsutrn() to translate non-standard CUNITia keyvalues,
+ * e.g. 'DEG' -> 'deg', also stripping off unnecessary whitespace.
+ *
++* unitfix() is expected to be invoked before wcsset(), which will fail if
++* non-standard CUNITia keyvalues have not been translated.
++*
+ * Given:
+ *   ctrl      int       Do potentially unsafe translations described in the
+ *                       usage notes to wcsutrn().
+@@ -332,9 +350,10 @@
  *                         0: Success (an alias was applied).
  *                         1: Null wcsprm pointer passed.
  *
@@ -28352,7 +33474,24 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.h
  *
  *
  * spcfix() - Translate AIPS-convention spectral types
-@@ -364,8 +364,10 @@
+@@ -345,6 +364,16 @@
+ *
+ * Note that if wcs::specsys is already set then it will not be overridden.
+ *
++* AIPS-convention spectral types set in CTYPEia are translated on-the-fly by
++* wcsset() but without modifying wcsprm::ctype[] or wcsprm::specsys.  That is,
++* only the information extracted from wcsprm::ctype[] is translated when
++* wcsset() fills in wcsprm::spc (spcprm struct).  spcfix() modifies
++* wcsprm::ctype[] so that if the header is subsequently written out, e.g. by
++* wcshdo(), then it will contain translated CTYPEia keyvalues.
++*
++* The operations done by spcfix() do not affect and are not affected by
++* wcsset().
++*
+ * Given and returned:
+ *   wcs       struct wcsprm*
+ *                       Coordinate transformation parameters.  wcsprm::ctype[]
+@@ -364,8 +393,10 @@
  *                         7: Ill-conditioned coordinate transformation
  *                            parameters.
  *
@@ -28365,7 +33504,136 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.h
  *
  *
  * celfix() - Translate AIPS-convention celestial projection types
-@@ -465,29 +467,27 @@ extern const char *wcsfix_errmsg[];
+@@ -379,6 +410,18 @@
+ * necessary.  Otherwise, error 2 will be returned if sufficient empty slots
+ * are not already available for use.
+ *
++* AIPS-convention celestial projection types set in CTYPEia are translated
++* on-the-fly by wcsset() but without modifying wcsprm::ctype[], wcsprm::pv[],
++* or wcsprm::npv.  That is, only the information extracted from
++* wcsprm::ctype[] is translated when wcsset() fills in wcsprm::cel (celprm
++* struct).  celfix() modifies wcsprm::ctype[], wcsprm::pv[], and wcsprm::npv
++* so that if the header is subsequently written out, e.g. by wcshdo(), then it
++* will contain translated CTYPEia keyvalues and the relevant PVi_ma.
++*
++* The operations done by celfix() do not affect and are not affected by
++* wcsset().  However, it uses information in the wcsprm struct provided by
++* wcsset(), and will invoke it if necessary.
++*
+ * Given and returned:
+ *   wcs       struct wcsprm*
+ *                       Coordinate transformation parameters.  wcsprm::ctype[]
+@@ -407,6 +450,10 @@
+ * cylfix() fixes WCS keyvalues for malformed cylindrical projections that
+ * suffer from the problem described in Sect. 7.3.4 of Paper I.
+ *
++* cylfix() requires the wcsprm struct to have been set up by wcsset(), and
++* will invoke it if necessary.  After modification, the struct is reset on
++* return with an explicit call to wcsset().
++*
+ * Given:
+ *   naxis     const int []
+ *                       Image axis lengths.
+@@ -436,6 +483,98 @@
+ *                       wcsprm::err if enabled, see wcserr_enable().
+ *
+ *
++* wcspcx() - regularize PCi_j
++* ---------------------------
++* wcspcx() "regularizes" the linear transformation matrix component of the
++* coordinate transformation (PCi_ja) to make it more human-readable.
++*
++* Normally, upon encountering a FITS header containing a CDi_ja matrix,
++* wcsset() simply treats it as PCi_ja and sets CDELTia to unity.  However,
++* wcspcx() decomposes CDi_ja into PCi_ja and CDELTia in such a way that
++* CDELTia form meaningful scaling parameters.  In practice, the residual
++* PCi_ja matrix will often then be orthogonal, i.e. unity, or describing a
++* pure rotation, axis permutation, or reflection, or a combination thereof.
++*
++* The decomposition is based on normalizing the length in the transformed
++* system (i.e. intermediate pixel coordinates) of the orthonormal basis
++* vectors of the pixel coordinate system.  This deviates slightly from the
++* prescription given by Eq. (4) of WCS Paper I, namely Sum(j=1,N)(PCi_ja)² = 1,
++* in replacing the sum over j with the sum over i.  Consequently, the columns
++* of PCi_ja will consist of unit vectors.  In practice, especially in cubes
++* and higher dimensional images, at least some pairs of these unit vectors, if
++* not all, will often be orthogonal or close to orthogonal.
++*
++* The sign of CDELTia is chosen to make the PCi_ja matrix as close to the,
++* possibly permuted, unit matrix as possible, except that where the coordinate
++* description contains a pair of celestial axes, the sign of CDELTia is set
++* negative for the longitude axis and positive for the latitude axis.
++*
++* Optionally, rows of the PCi_ja matrix may also be permuted to diagonalize
++* it as far as possible, thus undoing any transposition of axes in the
++* intermdiate pixel coordinate system.
++*
++* If the coordinate description contains a celestial plane, then the angle of
++* rotation of each of the basis vectors associated with the celestial axes is
++* returned.  For a pure rotation the two angles should be identical.  Any
++* difference between them is a measure of axis skewness.
++*
++* The decomposition is not performed for axes involving a sequent distortion
++* function that is defined in terms of CDi_ja, such as TPV, TNX, or ZPX, which
++* always are.  The independent variables of the polynomial are therefore
++* intermediate world coordinates rather than intermediate pixel coordinates.
++* Because sequent distortions are always applied before CDELTia, if CDi_ja was
++* translated to PCi_ja plus CDELTia, then the distortion would be altered
++* unless the polynomial coefficients were also adjusted to account for the
++* change of scale.
++*
++* wcspcx() requires the wcsprm struct to have been set up by wcsset(), and
++* will invoke it if necessary.  The wcsprm struct is reset on return with an
++* explicit call to wcsset().
++*
++* Given and returned:
++*   wcs       struct wcsprm*
++*                       Coordinate transformation parameters.
++*
++* Given:
++*   dopc      int       If 1, then PCi_ja and CDELTia, as given, will be
++*                       recomposed according to the above prescription.  If 0,
++*                       the operation is restricted to decomposing CDi_ja.
++*
++*   permute   int       If 1, then after decomposition (or recomposition),
++*                       permute rows of PCi_ja to make the axes of the
++*                       intermediate pixel coordinate system match as closely
++*                       as possible those of the pixel coordinates.  That is,
++*                       make it as close to a diagonal matrix as possible.
++*                       However, celestial axes are special in always being
++*                       paired, with the longitude axis preceding the latitude
++*                       axis.
++*
++*                       All WCS entities indexed by i, such as CTYPEia,
++*                       CRVALia, CDELTia, etc., including coordinate lookup
++*                       tables, will also be permuted as necessary to account
++*                       for the change to PCi_ja.  This does not apply to
++*                       CRPIXja, nor prior distortion functions.  These
++*                       operate on pixel coordinates, which are not affected
++*                       by the permutation.
++*
++* Returned:
++*   rotn      double[2] Rotation angle [deg] of each basis vector associated
++*                       with the celestial axes.  For a pure rotation the two
++*                       angles should be identical.  Any difference between
++*                       them is a measure of axis skewness.
++*
++*                       May be set to the NULL pointer if this information is
++*                       not required.
++*
++* Function return value:
++*             int       Status return value:
++*                         0: Success.
++*                         1: Null wcsprm pointer passed.
++*                         2: Memory allocation failed.
++*                         5: CDi_j matrix not used.
++*                         6: Sequent distortion function present.
++*
++*
+ * Global variable: const char *wcsfix_errmsg[] - Status return messages
+ * ---------------------------------------------------------------------
+ * Error messages to match the status value returned from each function.
+@@ -465,29 +604,27 @@ extern const char *wcsfix_errmsg[];
  #define cylfix_errmsg wcsfix_errmsg
  
  enum wcsfix_errmsg_enum {
@@ -28416,22 +33684,29 @@ Index: astropy-4.2/cextern/wcslib/C/wcsfix.h
  };
  
  int wcsfix(int ctrl, const int naxis[], struct wcsprm *wcs, int stat[]);
-@@ -514,4 +514,4 @@ int cylfix(const int naxis[], struct wcs
+@@ -509,9 +646,11 @@ int celfix(struct wcsprm *wcs);
+ 
+ int cylfix(const int naxis[], struct wcsprm *wcs);
+ 
++int wcspcx(struct wcsprm *wcs, int dopc, int permute, double rotn[2]);
++
+ 
+ #ifdef __cplusplus
  }
  #endif
  
 -#endif /* WCSLIB_WCSFIX */
 +#endif // WCSLIB_WCSFIX
-Index: astropy-4.2/cextern/wcslib/C/wcshdr.c
+Index: astropy-4.2.1/cextern/wcslib/C/wcshdr.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcshdr.c
-+++ astropy-4.2/cextern/wcslib/C/wcshdr.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcshdr.c
++++ astropy-4.2.1/cextern/wcslib/C/wcshdr.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -28445,7 +33720,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcshdr.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcshdr.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcshdr.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcshdr.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <ctype.h>
@@ -29916,16 +35191,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcshdr.c
      nc -= (nv - 20);
    }
  
-Index: astropy-4.2/cextern/wcslib/C/wcshdr.h
+Index: astropy-4.2.1/cextern/wcslib/C/wcshdr.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcshdr.h
-+++ astropy-4.2/cextern/wcslib/C/wcshdr.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcshdr.h
++++ astropy-4.2.1/cextern/wcslib/C/wcshdr.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -29939,11 +35214,11 @@ Index: astropy-4.2/cextern/wcslib/C/wcshdr.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcshdr.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcshdr.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcshdr.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
@@ -30140,16 +35415,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcshdr.h
  
 -#endif /* WCSLIB_WCSHDR */
 +#endif // WCSLIB_WCSHDR
-Index: astropy-4.2/cextern/wcslib/C/wcslib.h
+Index: astropy-4.2.1/cextern/wcslib/C/wcslib.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcslib.h
-+++ astropy-4.2/cextern/wcslib/C/wcslib.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcslib.h
++++ astropy-4.2.1/cextern/wcslib/C/wcslib.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -30163,11 +35438,11 @@ Index: astropy-4.2/cextern/wcslib/C/wcslib.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcslib.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcslib.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcslib.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
@@ -30177,16 +35452,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcslib.h
  
 -#endif /* WCSLIB_WCSLIB */
 +#endif // WCSLIB_WCSLIB
-Index: astropy-4.2/cextern/wcslib/C/wcsmath.h
+Index: astropy-4.2.1/cextern/wcslib/C/wcsmath.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcsmath.h
-+++ astropy-4.2/cextern/wcslib/C/wcsmath.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcsmath.h
++++ astropy-4.2.1/cextern/wcslib/C/wcsmath.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -30200,11 +35475,11 @@ Index: astropy-4.2/cextern/wcslib/C/wcsmath.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcsmath.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcsmath.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcsmath.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
@@ -30214,16 +35489,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcsmath.h
  
 -#endif /* WCSLIB_WCSMATH */
 +#endif // WCSLIB_WCSMATH
-Index: astropy-4.2/cextern/wcslib/C/wcspih.l
+Index: astropy-4.2.1/cextern/wcslib/C/wcspih.l
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcspih.l
-+++ astropy-4.2/cextern/wcslib/C/wcspih.l
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcspih.l
++++ astropy-4.2.1/cextern/wcslib/C/wcspih.l
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -30237,104 +35512,212 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcspih.l,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcspih.l,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcspih.l,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
  * wcspih.l is a Flex description file containing the definition of a lexical
-@@ -141,7 +138,7 @@ static int wcspih_scanner(char *header,
-                           int *nreject, int *nwcs, struct wcsprm **wcs,
-                           yyscan_t yyscanner);
+@@ -73,6 +70,7 @@
+ %option outfile="wcspih.c"
+ %option prefix="wcspih"
+ %option reentrant
++%option extra-type="struct wcspih_extra *"
  
+ /* Indices for parameterized keywords. */
+ Z1	[0-9]
+@@ -137,58 +135,37 @@ INLINE " "*(\/.*)?
+ #define DSS     2
+ #define WAT     3
+ 
+-static int wcspih_scanner(char *header, int nkeyrec, int relax, int ctrl,
+-                          int *nreject, int *nwcs, struct wcsprm **wcs,
+-                          yyscan_t yyscanner);
+-
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
- 
- int wcspih(
-   char *header,
-@@ -166,7 +163,7 @@ int wcspih(
-   return status;
- }
- 
+-
+-int wcspih(
+-  char *header,
+-  int nkeyrec,
+-  int relax,
+-  int ctrl,
+-  int *nreject,
+-  int *nwcs,
+-  struct wcsprm **wcs)
+-
+-{
+-  int status;
+-  yyscan_t yyscanner;
+-  int yylex_init(yyscan_t *yyscanner);
+-  int yylex_destroy(yyscan_t yyscanner);
+-
+-  yylex_init(&yyscanner);
+-  status = wcspih_scanner(header, nkeyrec, relax, ctrl, nreject, nwcs, wcs,
+-                          yyscanner);
+-  yylex_destroy(yyscanner);
+-
+-  return status;
+-}
+-
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
++// User data associated with yyscanner.
++struct wcspih_extra {
++  // Values passed to YY_INPUT.
++  char *hdr;
++  int  nkeyrec;
++
++  // Used in preempting the call to exit() by yy_fatal_error().
++  jmp_buf abort_jmp_env;
++};
  
  #define YY_DECL int wcspih_scanner(char *header, int nkeyrec, int relax, \
   int ctrl, int *nreject, int *nwcs, struct wcsprm **wcs, yyscan_t yyscanner)
-@@ -184,11 +181,11 @@ int wcspih(
+ 
+ #define YY_INPUT(inbuff, count, bufsize) \
+ 	{ \
+-	  if (wcspih_nkeyrec) { \
+-	    strncpy(inbuff, wcspih_hdr, 80); \
++	  if (yyextra->nkeyrec) { \
++	    strncpy(inbuff, yyextra->hdr, 80); \
+ 	    inbuff[80] = '\n'; \
+-	    wcspih_hdr += 80; \
+-	    wcspih_nkeyrec--; \
++	    yyextra->hdr += 80; \
++	    yyextra->nkeyrec--; \
+ 	    count = 81; \
+ 	  } else { \
+ 	    count = YY_NULL; \
  	  } \
  	}
  
 -/* These global variables are required by YY_INPUT. */
-+// These global variables are required by YY_INPUT.
- static char *wcspih_hdr;
- static int  wcspih_nkeyrec;
+-static char *wcspih_hdr;
+-static int  wcspih_nkeyrec;
++// Preempt the call to exit() by yy_fatal_error().
++#define exit(status) longjmp(yyextra->abort_jmp_env, status);
  
 -/* Internal helper functions. */
 +// Internal helper functions.
++static YY_DECL;
  static int wcspih_final(int ndp[], int ndq[], int distran, double dsstmp[],
               char *wat[], int *nwcs, struct wcsprm **wcs);
  static int wcspih_init1(int naxis, int alts[], int dpq[], int npv[],
-@@ -205,14 +202,14 @@ static int wcspih_vsource(double *wptr,
+@@ -205,34 +182,20 @@ static int wcspih_vsource(double *wptr,
  
  static int wcspih_timepixr(double timepixr);
  
 -/* Used in preempting the call to exit() by yy_fatal_error(). */
-+// Used in preempting the call to exit() by yy_fatal_error().
- jmp_buf wcspih_abort_jmp_env;
- #define exit(status) longjmp(wcspih_abort_jmp_env, status)
- 
+-jmp_buf wcspih_abort_jmp_env;
+-#define exit(status) longjmp(wcspih_abort_jmp_env, status)
+-
  %}
  
  %%
 -	/* Keyword indices, as used in the WCS papers, e.g. PCi_ja, PVi_ma. */
-+	// Keyword indices, as used in the WCS papers, e.g. PCi_ja, PVi_ma.
- 	char a;
- 	int  i, j, m, p, q;
+-	char a;
+-	int  i, j, m, p, q;
+-	
+-	char *cptr, *errmsg, errtxt[80], *hptr, *keep, *keyname, *keyrec,
+-	     keyword[16], strtmp[80], *wat[2], *watstr;
+-	int  altlin, alts[27], auxprm, distran, distype, dpq[27], dssflag,
+-	     gotone, ialt, inttmp, ipass, ipx, ix, jx, naux, naxis,
+-	     ndp[27], ndq[27], nother, *npptr, nps[27], npass, npv[27],
+-	     nvalid, rectype, sipflag, status, valtype, watflag, watn;
+-	ptrdiff_t voff;
++	int  p, q;
++	char *errmsg, errtxt[80], *keyname, strtmp[80], *wat[2], *watstr;
++	int  alts[27], dpq[27], inttmp, ndp[27], ndq[27], nps[27], npv[27],
++	     rectype;
+ 	double dbltmp, dbl2tmp[2], dsstmp[20];
+-	void *vptr, *wptr;
+-	struct auxprm *auxp, auxtem;
+-	struct disprm *disp, distem;
+-	struct wcsprm *wcsp, wcstem;
+-	int (*chekval)(double);
+-	int (*special)(double *, const double *);
++	struct auxprm auxtem;
++	struct disprm distem;
++	struct wcsprm wcstem;
  	
-@@ -241,34 +238,34 @@ jmp_buf wcspih_abort_jmp_env;
+-	naxis = 0;
+-	for (ialt = 0; ialt < 27; ialt++) {
++	int naxis = 0;
++	for (int ialt = 0; ialt < 27; ialt++) {
+ 	  alts[ialt] = 0;
+ 	  dpq[ialt]  = 0;
+ 	  npv[ialt]  = 0;
+@@ -241,57 +204,58 @@ jmp_buf wcspih_abort_jmp_env;
  	  ndq[ialt]  = 0;
  	}
  	
 -	/* Parameters used to implement YY_INPUT. */
-+	// Parameters used to implement YY_INPUT.
- 	wcspih_hdr = header;
- 	wcspih_nkeyrec = nkeyrec;
- 	
+-	wcspih_hdr = header;
+-	wcspih_nkeyrec = nkeyrec;
+-	
 -	/* Our handle on the input stream. */
+-	keyrec = header;
+-	hptr = header;
+-	keep = 0x0;
 +	// Our handle on the input stream.
- 	keyrec = header;
- 	hptr = header;
- 	keep = 0x0;
++	char *keyrec = header;
++	char *hptr = header;
++	char *keep = 0x0;
  	
 -	/* For keeping tallies of keywords found. */
 +	// For keeping tallies of keywords found.
  	*nreject = 0;
- 	nvalid = 0;
- 	nother = 0;
+-	nvalid = 0;
+-	nother = 0;
++	int nvalid = 0;
++	int nother = 0;
  	
 -	/* If strict, then also reject. */
 +	// If strict, then also reject.
  	if (relax & WCSHDR_strict) relax |= WCSHDR_reject;
  	
 -	/* Keyword parameters. */
-+	// Keyword parameters.
- 	i = j = 0;
- 	m = 0;
- 	a = ' ';
- 	
+-	i = j = 0;
+-	m = 0;
+-	a = ' ';
+-	
 -	/* For decoding the keyvalue. */
-+	// For decoding the keyvalue.
- 	valtype = -1;
- 	distype =  0;
- 	vptr    = 0x0;
- 	
+-	valtype = -1;
+-	distype =  0;
+-	vptr    = 0x0;
+-	
 -	/* For keywords that require special handling. */
+-	altlin  = 0;
+-	npptr   = 0x0;
+-	chekval = 0x0;
+-	special = 0x0;
+-	auxprm  = 0;
+-	naux    = 0;
+-	distran = 0;
+-	sipflag = 0;
+-	dssflag = 0;
+-	watflag = 0;
+-	watn    = 0;
++	// Keyword indices, as used in the WCS papers, e.g. PCi_ja, PVi_ma.
++	int i = 0;
++	int j = 0;
++	int m = 0;
++	char a = ' ';
++	
++	// For decoding the keyvalue.
++	int valtype = -1;
++	int distype =  0;
++	void *vptr  = 0x0;
++	
 +	// For keywords that require special handling.
- 	altlin  = 0;
- 	npptr   = 0x0;
- 	chekval = 0x0;
-@@ -281,15 +278,15 @@ jmp_buf wcspih_abort_jmp_env;
- 	watflag = 0;
- 	watn    = 0;
++	int altlin  = 0;
++	int *npptr  = 0x0;
++	int (*chekval)(double) = 0x0;
++	int (*special)(double *, const double *) = 0x0;
++	int auxprm  = 0;
++	int naux    = 0;
++	int distran = 0;
++	int sipflag = 0;
++	int dssflag = 0;
++	int watflag = 0;
++	int watn    = 0;
  	
 -	/* The data structures produced. */
 +	// The data structures produced.
@@ -30342,16 +35725,27 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	*wcs  = 0x0;
  	
 -	/* Control variables. */
-+	// Control variables.
- 	ipass = 1;
- 	npass = 2;
- 	
+-	ipass = 1;
+-	npass = 2;
+-	
 -	/* Return here via longjmp() invoked by yy_fatal_error(). */
+-	if (setjmp(wcspih_abort_jmp_env)) {
+-	  return 3;
++	// Control variables.
++	int ipass = 1;
++	int npass = 2;
++	
++	// User data associated with yyscanner.
++	yyextra->hdr = header;
++	yyextra->nkeyrec = nkeyrec;
++	
 +	// Return here via longjmp() invoked by yy_fatal_error().
- 	if (setjmp(wcspih_abort_jmp_env)) {
- 	  return 3;
++	if (setjmp(yyextra->abort_jmp_env)) {
++	  return WCSHDRERR_PARSER;
  	}
-@@ -627,7 +624,7 @@ jmp_buf wcspih_abort_jmp_env;
+ 	
+ 	BEGIN(INITIAL);
+@@ -627,7 +591,7 @@ jmp_buf wcspih_abort_jmp_env;
  ^MJDREFI" " |
  ^MJD-REFI {
  	  if ((yytext[3] == 'R') || (relax & WCSHDR_DATEREF)) {
@@ -30360,7 +35754,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	    valtype = FLOAT;
  	    vptr    = wcstem.mjdref;
  	
-@@ -683,7 +680,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -683,7 +647,7 @@ jmp_buf wcspih_abort_jmp_env;
  ^JDREFI"  " |
  ^JD-REFI {
  	  if ((yytext[2] == 'R') || (relax & WCSHDR_DATEREF)) {
@@ -30369,7 +35763,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	    valtype = FLOAT;
  	    vptr    = wcstem.mjdref;
  	    special = wcspih_jdrefi;
-@@ -1193,7 +1190,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1193,7 +1157,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^A_ORDER" " {
@@ -30378,7 +35772,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = INTEGER;
  	  distype = PRIOR;
  	  vptr    = 0x0;
-@@ -1206,7 +1203,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1206,7 +1170,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^B_ORDER" " {
@@ -30387,7 +35781,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = INTEGER;
  	  distype = PRIOR;
  	  vptr    = 0x0;
-@@ -1219,7 +1216,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1219,7 +1183,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^AP_ORDER {
@@ -30396,7 +35790,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = INTEGER;
  	  distype = PRIOR;
  	  vptr    = 0x0;
-@@ -1232,7 +1229,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1232,7 +1196,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^BP_ORDER {
@@ -30405,7 +35799,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = INTEGER;
  	  distype = PRIOR;
  	  vptr    = 0x0;
-@@ -1245,7 +1242,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1245,7 +1209,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^A_DMAX"  " {
@@ -30414,7 +35808,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = FLOAT;
  	  distype = PRIOR;
  	  vptr    = &(distem.maxdis);
-@@ -1258,7 +1255,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1258,7 +1222,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^B_DMAX"  " {
@@ -30423,7 +35817,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = FLOAT;
  	  distype = PRIOR;
  	  vptr    = &(distem.maxdis);
-@@ -1271,7 +1268,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1271,7 +1235,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^A_	{
@@ -30432,7 +35826,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  i = 1;
  	  sipflag = 2;
  	
-@@ -1280,7 +1277,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1280,7 +1244,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^B_	{
@@ -30441,7 +35835,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  i = 2;
  	  sipflag = 2;
  	
-@@ -1289,7 +1286,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1289,7 +1253,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^AP_	{
@@ -30450,7 +35844,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  i = 1;
  	  sipflag = 3;
  	
-@@ -1298,7 +1295,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1298,7 +1262,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^BP_	{
@@ -30459,7 +35853,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  i = 2;
  	  sipflag = 3;
  	
-@@ -1307,7 +1304,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1307,7 +1271,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^CNPIX1"  " {
@@ -30468,7 +35862,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp;
-@@ -1319,7 +1316,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1319,7 +1283,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^CNPIX2"  " {
@@ -30477,7 +35871,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+1;
-@@ -1331,7 +1328,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1331,7 +1295,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^PPO3"    " {
@@ -30486,7 +35880,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+2;
-@@ -1343,7 +1340,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1343,7 +1307,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^PPO6"    " {
@@ -30495,7 +35889,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+3;
-@@ -1355,7 +1352,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1355,7 +1319,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^XPIXELSZ {
@@ -30504,7 +35898,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+4;
-@@ -1367,7 +1364,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1367,7 +1331,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^YPIXELSZ {
@@ -30513,7 +35907,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+5;
-@@ -1379,7 +1376,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1379,7 +1343,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^PLTRAH"  " {
@@ -30522,7 +35916,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+6;
-@@ -1391,7 +1388,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1391,7 +1355,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^PLTRAM"  " {
@@ -30531,7 +35925,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+7;
-@@ -1403,7 +1400,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1403,7 +1367,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^PLTRAS"  " {
@@ -30540,7 +35934,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+8;
-@@ -1415,7 +1412,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1415,7 +1379,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^PLTDECSN {
@@ -30549,7 +35943,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = STRING;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+9;
-@@ -1427,7 +1424,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1427,7 +1391,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^PLTDECD" " {
@@ -30558,7 +35952,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+10;
-@@ -1439,7 +1436,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1439,7 +1403,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^PLTDECM" " {
@@ -30567,7 +35961,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+11;
-@@ -1451,7 +1448,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1451,7 +1415,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^PLTDECS" " {
@@ -30576,7 +35970,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+12;
-@@ -1463,7 +1460,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1463,7 +1427,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^PLATEID" " {
@@ -30585,7 +35979,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = STRING;
  	  distype = SEQUENT;
  	  vptr    = dsstmp+13;
-@@ -1475,7 +1472,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1475,7 +1439,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^AMDX	{
@@ -30594,7 +35988,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  i = 1;
  	  dssflag = 3;
  	
-@@ -1484,7 +1481,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1484,7 +1448,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^AMDY	{
@@ -30603,7 +35997,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  i = 2;
  	  dssflag = 3;
  	
-@@ -1493,7 +1490,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1493,7 +1457,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  ^WAT[12]_{Z3} {
@@ -30612,7 +36006,18 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  sscanf(yytext, "WAT%d_%d", &i, &m);
  	  if (watn < m) watn = m;
  	  watflag = 1;
-@@ -1539,13 +1536,13 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1510,8 +1474,8 @@ jmp_buf wcspih_abort_jmp_env;
+ 	}
+ 
+ ^END" "{77} {
+-	  if (wcspih_nkeyrec) {
+-	    wcspih_nkeyrec = 0;
++	  if (yyextra->nkeyrec) {
++	    yyextra->nkeyrec = 0;
+ 	    errmsg = "keyrecords following the END keyrecord were ignored";
+ 	    BEGIN(ERROR);
+ 	  } else {
+@@ -1539,13 +1503,13 @@ jmp_buf wcspih_abort_jmp_env;
  <CCCCCia>0{I1}{ALT}      |
  <CCCCCia>0{Z1}{I1} {
  	  if (relax & WCSHDR_reject) {
@@ -30628,7 +36033,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -1559,27 +1556,27 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1559,27 +1523,27 @@ jmp_buf wcspih_abort_jmp_env;
  <CCCCCia>{Z1}{ALT}" " |
  <CCCCCia>{Z2}{ALT}    |
  <CCCCCia>{Z3} {
@@ -30661,7 +36066,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -1625,7 +1622,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1625,7 +1589,7 @@ jmp_buf wcspih_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -30670,7 +36075,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -1640,8 +1637,8 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1640,8 +1604,8 @@ jmp_buf wcspih_abort_jmp_env;
  <CCi_ja>{Z3}_{Z2} |
  <CCi_ja>{Z2}_{Z3} |
  <CCi_ja>{Z1}_{Z4} {
@@ -30681,7 +36086,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  errmsg = "axis number must exceed 0";
  	  BEGIN(ERROR);
  	}
-@@ -1663,7 +1660,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1663,7 +1627,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  <CCi_ja>{Z2}{I1}{Z2}{I1} {
@@ -30690,7 +36095,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  if (((altlin == 1) && (relax & WCSHDR_PC00i00j)) ||
  	      ((altlin == 2) && (relax & WCSHDR_CD00i00j))) {
  	    sscanf(yytext, "%3d%3d", &i, &j);
-@@ -1678,7 +1675,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1678,7 +1642,7 @@ jmp_buf wcspih_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -30699,7 +36104,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -1701,14 +1698,14 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1701,14 +1665,14 @@ jmp_buf wcspih_abort_jmp_env;
  
  <CCCCCCCa>. {
  	  if (relax & WCSHDR_reject) {
@@ -30716,7 +36121,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -1753,7 +1750,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1753,7 +1717,7 @@ jmp_buf wcspih_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -30725,7 +36130,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -1768,8 +1765,8 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1768,8 +1732,8 @@ jmp_buf wcspih_abort_jmp_env;
  <CCi_ma>{Z3}_{Z2} |
  <CCi_ma>{Z2}_{Z3} |
  <CCi_ma>{Z1}_{Z4} {
@@ -30736,7 +36141,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  errmsg = "axis number must exceed 0";
  	  BEGIN(ERROR);
  	}
-@@ -1813,7 +1810,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1813,7 +1777,7 @@ jmp_buf wcspih_abort_jmp_env;
  	    BEGIN(ERROR);
  	
  	  } else {
@@ -30745,7 +36150,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	    BEGIN(DISCARD);
  	  }
  	}
-@@ -1856,7 +1853,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1856,7 +1820,7 @@ jmp_buf wcspih_abort_jmp_env;
  
  <SIP2>{Z1}_{Z1}"   " |
  <SIP3>{Z1}_{Z1}"  " {
@@ -30754,7 +36159,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = FLOAT;
  	  distype = PRIOR;
  	  vptr    = &(distem.dp);
-@@ -1876,7 +1873,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1876,7 +1840,7 @@ jmp_buf wcspih_abort_jmp_env;
  
  <DSSAMDXY>{I1}"   " |
  <DSSAMDXY>{I2}"  " {
@@ -30763,7 +36168,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  valtype = FLOAT;
  	  distype = SEQUENT;
  	  vptr    = &(distem.dp);
-@@ -1894,9 +1891,9 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1894,9 +1858,9 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  <PLTDECSN>=" "+{STRING} {
@@ -30775,7 +36180,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	    sscanf(yytext, "= '%s", strtmp);
  	    dbltmp = strcmp(strtmp, "-") ? 1.0 : -1.0;
  	  }
-@@ -1909,7 +1906,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1909,7 +1873,7 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  <VALUE>=" "+ {
@@ -30784,7 +36189,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  if (99 < i || 99 < j || 99 < m) {
  	    if (relax & WCSHDR_reject) {
  	      if (99 < i || 99 < j) {
-@@ -1920,7 +1917,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1920,7 +1884,7 @@ jmp_buf wcspih_abort_jmp_env;
  	      BEGIN(ERROR);
  	
  	    } else {
@@ -30793,7 +36198,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	      BEGIN(DISCARD);
  	    }
  	
-@@ -1954,7 +1951,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1954,7 +1918,7 @@ jmp_buf wcspih_abort_jmp_env;
  	    BEGIN(COMMENT);
  	
  	  } else {
@@ -30802,7 +36207,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	    sscanf(yytext, "%d", &inttmp);
  	
  	    BEGIN(COMMENT);
-@@ -1971,7 +1968,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1971,7 +1935,7 @@ jmp_buf wcspih_abort_jmp_env;
  	    BEGIN(COMMENT);
  	
  	  } else {
@@ -30811,7 +36216,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	    wcsutil_str2double(yytext, &dbltmp);
  
  	    if (chekval && chekval(dbltmp)) {
-@@ -1993,7 +1990,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -1993,7 +1957,7 @@ jmp_buf wcspih_abort_jmp_env;
  	    BEGIN(COMMENT);
  	
  	  } else {
@@ -30820,7 +36225,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	    wcsutil_str2double2(yytext, dbl2tmp);
  	
  	    BEGIN(COMMENT);
-@@ -2010,10 +2007,10 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -2010,12 +1974,12 @@ jmp_buf wcspih_abort_jmp_env;
  	    BEGIN(COMMENT);
  	
  	  } else {
@@ -30829,11 +36234,15 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	    strcpy(strtmp, yytext+1);
  	
 -	    /* Squeeze out repeated quotes. */
+-	    ix = 0;
+-	    for (jx = 0; jx < 72; jx++) {
 +	    // Squeeze out repeated quotes.
- 	    ix = 0;
- 	    for (jx = 0; jx < 72; jx++) {
++	    int ix = 0;
++	    for (int jx = 0; jx < 72; jx++) {
  	      if (ix < jx) {
-@@ -2097,16 +2094,16 @@ jmp_buf wcspih_abort_jmp_env;
+ 	        strtmp[ix] = strtmp[jx];
+ 	      }
+@@ -2097,16 +2061,16 @@ jmp_buf wcspih_abort_jmp_env;
  
  <COMMENT>{INLINE}$ {
  	  if (ipass == 1) {
@@ -30844,31 +36253,36 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	
  	  } else if (*wcs) {
 -	    /* Store the value now that the keyrecord has been validated. */
-+	    // Store the value now that the keyrecord has been validated.
- 	    gotone = 0;
- 	    for (ialt = 0; ialt < *nwcs; ialt++) {
+-	    gotone = 0;
+-	    for (ialt = 0; ialt < *nwcs; ialt++) {
 -	      /* The loop here is for keywords that apply */
 -	      /* to every alternate; these have a == 0. */
++	    // Store the value now that the keyrecord has been validated.
++	    int gotone = 0;
++	    for (int ialt = 0; ialt < *nwcs; ialt++) {
 +	      // The loop here is for keywords that apply
 +	      // to every alternate; these have a == 0.
  	      if (a >= 'A') {
  	        ialt = alts[a-'A'+1];
  	        if (ialt < 0) break;
-@@ -2115,11 +2112,11 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -2115,11 +2079,12 @@ jmp_buf wcspih_abort_jmp_env;
  	
  	      if (vptr) {
  	        if (sipflag) {
 -	          /* Translate a SIP keyword into DPja. */
+-	          disp = (*wcs)->lin.dispre;
+-	          ipx = (disp->ndp)++;
 +	          // Translate a SIP keyword into DPja.
- 	          disp = (*wcs)->lin.dispre;
- 	          ipx = (disp->ndp)++;
++	          struct disprm *disp = (*wcs)->lin.dispre;
++	          int ipx = (disp->ndp)++;
  	
 -	          /* SIP doesn't have alternates. */
 +	          // SIP doesn't have alternates.
++		  char keyword[16];
  	          sprintf(keyword, "DP%d", i);
  	          sprintf(strtmp, "SIP.%s.%d_%d", (sipflag==2)?"FWD":"REV",
  	                  p, q);
-@@ -2130,27 +2127,27 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -2130,27 +2095,28 @@ jmp_buf wcspih_abort_jmp_env;
  	          }
  	
  	        } else if (dssflag) {
@@ -30888,11 +36302,14 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
 -	            /* Translate a DSS keyword into DQia. */
 +	            // Translate a DSS keyword into DQia.
  	            if (m <= 13 || dbltmp != 0.0) {
- 	              disp = (*wcs)->lin.disseq;
- 	              ipx = (disp->ndp)++;
+-	              disp = (*wcs)->lin.disseq;
+-	              ipx = (disp->ndp)++;
++	              struct disprm *disp = (*wcs)->lin.disseq;
++	              int ipx = (disp->ndp)++;
  	
 -	              /* DSS doesn't have alternates. */
 +	              // DSS doesn't have alternates.
++		      char keyword[16];
  	              sprintf(keyword, "DQ%d", i);
  	              sprintf(strtmp, "DSS.AMD.%d", m);
  	              dpfill(disp->dp+ipx, keyword, strtmp, i, 1, 0, dbltmp);
@@ -30902,7 +36319,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	              if (m <= 3) {
  	                dsstmp[13+(i-1)*3+m] = dbltmp;
  	              }
-@@ -2158,32 +2155,32 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -2158,32 +2124,35 @@ jmp_buf wcspih_abort_jmp_env;
  	          }
  	
  	        } else if (watflag) {
@@ -30912,12 +36329,17 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	
  	        } else {
 -	          /* An "ordinary" keyword. */
+-	          wcsp = *wcs + ialt;
 +	          // An "ordinary" keyword.
- 	          wcsp = *wcs + ialt;
++	          struct wcsprm *wcsp = *wcs + ialt;
++		  struct disprm *disp;
++	          void *wptr;
++	          ptrdiff_t voff;
  	          if (auxprm) {
 -	            /* Additional auxiliary parameter. */
+-	            auxp = wcsp->aux;
 +	            // Additional auxiliary parameter.
- 	            auxp = wcsp->aux;
++	            struct auxprm *auxp = wcsp->aux;
  	            voff = (char *)vptr - (char *)(&auxtem);
  	            wptr = (void *)((char *)auxp + voff);
  	
@@ -30942,16 +36364,19 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	            voff = (char *)vptr - (char *)(&wcstem);
  	            wptr = (void *)((char *)wcsp + voff);
  	          }
-@@ -2192,7 +2189,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -2192,9 +2161,9 @@ jmp_buf wcspih_abort_jmp_env;
  	            *((int *)wptr) = inttmp;
  	
  	          } else if (valtype == FLOAT) {
 -	            /* Apply keyword parameterization. */
 +	            // Apply keyword parameterization.
  	            if (npptr == npv) {
- 	              ipx = (wcsp->npv)++;
+-	              ipx = (wcsp->npv)++;
++	              int ipx = (wcsp->npv)++;
  	              wcsp->pv[ipx].i = i;
-@@ -2213,14 +2210,14 @@ jmp_buf wcspih_abort_jmp_env;
+ 	              wcsp->pv[ipx].m = m;
+ 	              wptr = &(wcsp->pv[ipx].value);
+@@ -2213,14 +2182,14 @@ jmp_buf wcspih_abort_jmp_env;
  	              *((double *)wptr) = dbltmp;
  	            }
  	
@@ -30968,16 +36393,44 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	            if (special) {
  	              special(wptr, dbl2tmp);
  	            } else {
-@@ -2229,7 +2226,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -2229,9 +2198,9 @@ jmp_buf wcspih_abort_jmp_env;
  	            }
  	
  	          } else if (valtype == STRING) {
 -	            /* Apply keyword parameterization. */
 +	            // Apply keyword parameterization.
  	            if (npptr == nps) {
- 	              ipx = (wcsp->nps)++;
+-	              ipx = (wcsp->nps)++;
++	              int ipx = (wcsp->nps)++;
  	              wcsp->ps[ipx].i = i;
-@@ -2312,7 +2309,7 @@ jmp_buf wcspih_abort_jmp_env;
+ 	              wcsp->ps[ipx].m = m;
+ 	              wptr = wcsp->ps[ipx].value;
+@@ -2244,12 +2213,13 @@ jmp_buf wcspih_abort_jmp_env;
+ 	              wptr = *((char (**)[72])wptr) + (i - 1);
+ 	            }
+ 	
+-	            cptr = (char *)wptr;
++	            char *cptr = (char *)wptr;
+ 	            strcpy(cptr, strtmp);
+ 	
+ 	          } else if (valtype == RECORD) {
+-	            ipx = (disp->ndp)++;
++	            int ipx = (disp->ndp)++;
+ 	
++		    char keyword[16];
+ 	            if (a == ' ') {
+ 	              sprintf(keyword, "%.2s%d", keyname, i);
+ 	            } else {
+@@ -2270,7 +2240,7 @@ jmp_buf wcspih_abort_jmp_env;
+ 	      if (ctrl == 4) {
+ 	        if (distran || dssflag) {
+ 	          wcsfprintf(stderr, "%.80s\n  Accepted (%d) as a "
+-	            "recognised WCS convention.\n", keyrec, nvalid);
++	            "recognized WCS convention.\n", keyrec, nvalid);
+ 	        } else {
+ 	          wcsfprintf(stderr, "%.80s\n  Accepted (%d) as a "
+ 	            "valid WCS keyrecord.\n", keyrec, nvalid);
+@@ -2312,7 +2282,7 @@ jmp_buf wcspih_abort_jmp_env;
  <DISCARD>.*$ {
  	  if (ipass == npass) {
  	    if (ctrl < 0) {
@@ -30986,7 +36439,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	      keep = keyrec;
  	
  	    } else if (2 < ctrl) {
-@@ -2329,7 +2326,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -2329,7 +2299,7 @@ jmp_buf wcspih_abort_jmp_env;
  	    (*nreject)++;
  	
  	    if (ctrl%10 == -1) {
@@ -30995,7 +36448,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	      keep = keyrec;
  	    }
  	
-@@ -2351,7 +2348,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -2351,7 +2321,7 @@ jmp_buf wcspih_abort_jmp_env;
  	
  	  naux += auxprm;
  	
@@ -31004,27 +36457,87 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  	  i = j = 0;
  	  m = 0;
  	  a = ' ';
-@@ -2376,7 +2373,7 @@ jmp_buf wcspih_abort_jmp_env;
+@@ -2376,7 +2346,8 @@ jmp_buf wcspih_abort_jmp_env;
  	}
  
  <<EOF>>	 {
 -	  /* End-of-input. */
 +	  // End-of-input.
++	  int status;
  	  if (ipass == 1) {
  	    if ((status = wcspih_init1(naxis, alts, dpq, npv, nps, ndp, ndq,
  	                               naux, distran, nwcs, wcs)) ||
-@@ -2467,8 +2464,8 @@ void wcspih_pass1(
+@@ -2401,8 +2372,8 @@ jmp_buf wcspih_abort_jmp_env;
+ 	  }
+ 	
+ 	  if (ipass++ < npass) {
+-	    wcspih_hdr = header;
+-	    wcspih_nkeyrec = nkeyrec;
++	    yyextra->hdr = header;
++	    yyextra->nkeyrec = nkeyrec;
+ 	    keyrec = header;
+ 	    *nreject = 0;
+ 	
+@@ -2451,6 +2422,35 @@ jmp_buf wcspih_abort_jmp_env;
+ %%
+ 
+ /*----------------------------------------------------------------------------
++* External interface to the scanner.
++*---------------------------------------------------------------------------*/
++
++int wcspih(
++  char *header,
++  int nkeyrec,
++  int relax,
++  int ctrl,
++  int *nreject,
++  int *nwcs,
++  struct wcsprm **wcs)
++
++{
++  // Function prototypes.
++  int yylex_init_extra(YY_EXTRA_TYPE extra, yyscan_t *yyscanner);
++  int yylex_destroy(yyscan_t yyscanner);
++
++  struct wcspih_extra extra;
++  yyscan_t yyscanner;
++  yylex_init_extra(&extra, &yyscanner);
++  int status = wcspih_scanner(header, nkeyrec, relax, ctrl, nreject, nwcs,
++                              wcs, yyscanner);
++  yylex_destroy(yyscanner);
++
++  return status;
++}
++
++
++/*----------------------------------------------------------------------------
+ * Determine the number of coordinate representations (up to 27) and the
+ * number of coordinate axes in each, which distortions are present, and the
+ * number of PVi_ma, PSi_ma, DPja, and DQia keywords in each representation.
+@@ -2467,26 +2467,24 @@ void wcspih_pass1(
    int *npptr)
  
  {
 -  /* On the first pass alts[] is used to determine the number of axes */
 -  /* for each of the 27 possible alternate coordinate descriptions.   */
+-  int ialt, *ip;
+-
 +  // On the first pass alts[] is used to determine the number of axes
 +  // for each of the 27 possible alternate coordinate descriptions.
-   int ialt, *ip;
- 
    if (a == 0) {
-@@ -2486,7 +2483,7 @@ void wcspih_pass1(
+     return;
+   }
+ 
+-  ialt = 0;
++  int ialt = 0;
+   if (a != ' ') {
+     ialt = a - 'A' + 1;
+   }
+ 
+-  ip = alts + ialt;
++  int *ip = alts + ialt;
+ 
+   if (*ip < naxis) {
      *ip = naxis;
    }
  
@@ -31033,7 +36546,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
    if (*ip < i) {
      *ip = i;
    }
-@@ -2495,10 +2492,10 @@ void wcspih_pass1(
+@@ -2495,10 +2493,10 @@ void wcspih_pass1(
      *ip = j;
    }
  
@@ -31046,17 +36559,24 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
    if (npptr) {
      npptr[ialt]++;
    }
-@@ -2528,37 +2525,37 @@ int wcspih_init1(
-   struct wcsprm *wcsp;
-   struct disprm *dis;
+@@ -2524,115 +2522,115 @@ int wcspih_init1(
+   struct wcsprm **wcs)
+ 
+ {
+-  int ialt, defaults, ndis, ndpmax, npsmax, npvmax, status = 0;
+-  struct wcsprm *wcsp;
+-  struct disprm *dis;
++  int status = 0;
  
 -  /* Find the number of coordinate descriptions. */
 +  // Find the number of coordinate descriptions.
    *nwcs = 0;
-   for (ialt = 0; ialt < 27; ialt++) {
+-  for (ialt = 0; ialt < 27; ialt++) {
++  for (int ialt = 0; ialt < 27; ialt++) {
      if (alts[ialt]) (*nwcs)++;
    }
  
++  int defaults;
    if ((defaults = !(*nwcs) && naxis)) {
 -    /* NAXIS is non-zero but there were no WCS keywords with an alternate
 -       version code; create a default WCS with blank alternate version. */
@@ -31073,7 +36593,8 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
        return WCSHDRERR_MEMORY;
      }
  
-     ndis = 0;
+-    ndis = 0;
++    int ndis = 0;
      if (distran == SIP) {
 -      /* DPja.NAXES and DPja.OFFSET.j to be added for SIP (see below and
 -         wcspih_final()). */
@@ -31088,11 +36609,20 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
      }
  
 -    /* Initialize each wcsprm struct. */
+-    wcsp = *wcs;
 +    // Initialize each wcsprm struct.
-     wcsp = *wcs;
++    struct wcsprm *wcsp = *wcs;
      *nwcs = 0;
-     for (ialt = 0; ialt < 27; ialt++) {
-@@ -2571,30 +2568,30 @@ int wcspih_init1(
+-    for (ialt = 0; ialt < 27; ialt++) {
++    for (int ialt = 0; ialt < 27; ialt++) {
+       if (alts[ialt]) {
+         wcsp->flag = -1;
+-        npvmax = npv[ialt];
+-        npsmax = nps[ialt];
++        int npvmax = npv[ialt];
++        int npsmax = nps[ialt];
+         if ((status = wcsinit(1, alts[ialt], wcsp, npvmax, npsmax, -1))) {
+           wcsvfree(nwcs, wcs);
            break;
          }
  
@@ -31118,26 +36648,39 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  
 -        /* Any distortions present? */
 +        // Any distortions present?
++        struct disprm *disp;
          if (dpq[ialt] & 1) {
-           if ((dis = calloc(1, sizeof(struct disprm))) == 0x0) {
+-          if ((dis = calloc(1, sizeof(struct disprm))) == 0x0) {
++          if ((disp = calloc(1, sizeof(struct disprm))) == 0x0) {
              return WCSHDRERR_MEMORY;
            }
  
 -          /* Attach it to linprm.  Also inits it. */
 +          // Attach it to linprm.  Also inits it.
            ndis++;
-           ndpmax = ndp[ialt];
-           dis->flag = -1;
-@@ -2606,33 +2603,33 @@ int wcspih_init1(
+-          ndpmax = ndp[ialt];
+-          dis->flag = -1;
+-          lindist(1, &(wcsp->lin), dis, ndpmax);
++          int ndpmax = ndp[ialt];
++          disp->flag = -1;
++          lindist(1, &(wcsp->lin), disp, ndpmax);
+         }
+ 
+         if (dpq[ialt] & 2) {
+-          if ((dis = calloc(1, sizeof(struct disprm))) == 0x0) {
++          if ((disp = calloc(1, sizeof(struct disprm))) == 0x0) {
              return WCSHDRERR_MEMORY;
            }
  
 -          /* Attach it to linprm.  Also inits it. */
 +          // Attach it to linprm.  Also inits it.
            ndis++;
-           ndpmax = ndq[ialt];
-           dis->flag = -1;
-           lindist(2, &(wcsp->lin), dis, ndpmax);
+-          ndpmax = ndq[ialt];
+-          dis->flag = -1;
+-          lindist(2, &(wcsp->lin), dis, ndpmax);
++          int ndpmax = ndq[ialt];
++          disp->flag = -1;
++          lindist(2, &(wcsp->lin), disp, ndpmax);
          }
  
 -        /* On the second pass alts[] indexes the array of wcsprm structs. */
@@ -31169,7 +36712,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
        (*wcs)->lin.dispre->ndp = 6;
        dpfill((*wcs)->lin.dispre->dp,   "DP1", "NAXES",  0, 0, 2, 0.0);
        dpfill((*wcs)->lin.dispre->dp+3, "DP2", "NAXES",  0, 0, 2, 0.0);
-@@ -2641,7 +2638,7 @@ int wcspih_init1(
+@@ -2641,7 +2639,7 @@ int wcspih_init1(
        strcpy((*wcs)->lin.disseq->dtype[0], "DSS");
        strcpy((*wcs)->lin.disseq->dtype[1], "DSS");
  
@@ -31178,7 +36721,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
        (*wcs)->lin.disseq->ndp = 2;
        dpfill((*wcs)->lin.disseq->dp,   "DQ1", "NAXES",  0, 0, 2, 0.0);
        dpfill((*wcs)->lin.disseq->dp+1, "DQ2", "NAXES",  0, 0, 2, 0.0);
-@@ -2659,7 +2656,7 @@ int wcspih_init1(
+@@ -2659,7 +2657,7 @@ int wcspih_init1(
  int wcspih_jdref(double *mjdref, const double *jdref)
  
  {
@@ -31187,7 +36730,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
    if (undefined(mjdref[0] && undefined(mjdref[1]))) {
      mjdref[0] = jdref[0] - 2400000.0;
      mjdref[1] = jdref[1] - 0.5;
-@@ -2676,7 +2673,7 @@ int wcspih_jdref(double *mjdref, const d
+@@ -2676,7 +2674,7 @@ int wcspih_jdref(double *mjdref, const d
  int wcspih_jdrefi(double *mjdref, const double *jdrefi)
  
  {
@@ -31196,7 +36739,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
    if (undefined(mjdref[0])) {
      mjdref[0] = *jdrefi - 2400000.5;
    }
-@@ -2688,7 +2685,7 @@ int wcspih_jdrefi(double *mjdref, const
+@@ -2688,7 +2686,7 @@ int wcspih_jdrefi(double *mjdref, const
  int wcspih_jdreff(double *mjdref, const double *jdreff)
  
  {
@@ -31205,7 +36748,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
    if (undefined(mjdref[1])) {
      mjdref[1] = *jdreff;
    }
-@@ -2704,7 +2701,7 @@ int wcspih_jdreff(double *mjdref, const
+@@ -2704,7 +2702,7 @@ int wcspih_jdreff(double *mjdref, const
  int wcspih_epoch(double *equinox, const double *epoch)
  
  {
@@ -31214,24 +36757,39 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
    if (undefined(*equinox)) {
      *equinox = *epoch;
    }
-@@ -2722,9 +2719,9 @@ int wcspih_vsource(double *zsource, cons
+@@ -2720,12 +2718,12 @@ int wcspih_epoch(double *equinox, const
+ int wcspih_vsource(double *zsource, const double *vsource)
+ 
  {
-   double beta, c = 299792458.0;
+-  double beta, c = 299792458.0;
++  const double c = 299792458.0;
  
 -  /* If ZSOURCEa is currently undefined then set it from VSOURCEa. */
 +  // If ZSOURCEa is currently undefined then set it from VSOURCEa.
    if (undefined(*zsource)) {
 -    /* Convert relativistic Doppler velocity to redshift. */
+-    beta = *vsource/c;
 +    // Convert relativistic Doppler velocity to redshift.
-     beta = *vsource/c;
++    double beta = *vsource/c;
      *zsource = (1.0 + beta)/sqrt(1.0 - beta*beta) - 1.0;
    }
-@@ -2766,23 +2763,23 @@ int wcspih_final(
-   struct wcsprm *wcsp;
  
-   for (ialt = 0; ialt < *nwcs; ialt++) {
+@@ -2758,58 +2756,52 @@ int wcspih_final(
+   struct wcsprm **wcs)
+ 
+ {
+-  char   field[32], *wp, wpoly[12], wtype[8];
+-  int    i, ialt, idp, ipv, m, npv, n, nterms, omax, omin, status, wctrl[4];
+-  double A1, A2, A3, B1, B2, B3, CNPIX1, CNPIX2, *crval, Rx, Ry, S, wval,
+-         X0, Y0, Xc, Yc;
+-  struct disprm *disp;
+-  struct wcsprm *wcsp;
+-
+-  for (ialt = 0; ialt < *nwcs; ialt++) {
 -    /* Interpret -TAB header keywords. */
++  for (int ialt = 0; ialt < *nwcs; ialt++) {
 +    // Interpret -TAB header keywords.
++    int status;
      if ((status = wcstab(*wcs+ialt))) {
         wcsvfree(nwcs, wcs);
         return status;
@@ -31247,26 +36805,72 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
    }
  
 -  /* Translated distortion functions; apply only to the primary WCS. */
+-  wcsp = *wcs;
 +  // Translated distortion functions; apply only to the primary WCS.
-   wcsp = *wcs;
++  struct wcsprm *wcsp = *wcs;
    if (distran == SIP) {
 -    /* SIP doesn't have alternates, nor axis mapping. */
+-    disp = wcsp->lin.dispre;
 +    // SIP doesn't have alternates, nor axis mapping.
-     disp = wcsp->lin.dispre;
++    struct disprm *disp = wcsp->lin.dispre;
      dpfill(disp->dp+1, "DP1", "OFFSET.1",  0, 1, 0, wcsp->crpix[0]);
      dpfill(disp->dp+2, "DP1", "OFFSET.2",  0, 1, 0, wcsp->crpix[1]);
-@@ -2790,8 +2787,8 @@ int wcspih_final(
+     dpfill(disp->dp+4, "DP2", "OFFSET.1",  0, 1, 0, wcsp->crpix[0]);
      dpfill(disp->dp+5, "DP2", "OFFSET.2",  0, 1, 0, wcsp->crpix[1]);
  
    } else if (distran == DSS) {
 -    /* DSS doesn't have alternates, nor axis mapping.  This translation */
 -    /* follows Paper IV, Sect. 5.2 using the same variable names.       */
+-    CNPIX1 = dsstmp[0];
+-    CNPIX2 = dsstmp[1];
+-
+-    Xc = dsstmp[2]/1000.0;
+-    Yc = dsstmp[3]/1000.0;
+-    Rx = dsstmp[4]/1000.0;
+-    Ry = dsstmp[5]/1000.0;
+-
+-    A1 = dsstmp[14];
+-    A2 = dsstmp[15];
+-    A3 = dsstmp[16];
+-    B1 = dsstmp[17];
+-    B2 = dsstmp[18];
+-    B3 = dsstmp[19];
+-    S  = sqrt(fabs(A1*B1 - A2*B2));
 +    // DSS doesn't have alternates, nor axis mapping.  This translation
 +    // follows Paper IV, Sect. 5.2 using the same variable names.
-     CNPIX1 = dsstmp[0];
-     CNPIX2 = dsstmp[1];
++    double CNPIX1 = dsstmp[0];
++    double CNPIX2 = dsstmp[1];
++
++    double Xc = dsstmp[2]/1000.0;
++    double Yc = dsstmp[3]/1000.0;
++    double Rx = dsstmp[4]/1000.0;
++    double Ry = dsstmp[5]/1000.0;
++
++    double A1 = dsstmp[14];
++    double A2 = dsstmp[15];
++    double A3 = dsstmp[16];
++    double B1 = dsstmp[17];
++    double B2 = dsstmp[18];
++    double B3 = dsstmp[19];
++    double S  = sqrt(fabs(A1*B1 - A2*B2));
  
-@@ -2833,17 +2830,17 @@ int wcspih_final(
+-    X0 = (A2*B3 - A3*B1) / (A1*B1 - A2*B2);
+-    Y0 = (A3*B2 - A1*B3) / (A1*B1 - A2*B2);
++    double X0 = (A2*B3 - A3*B1) / (A1*B1 - A2*B2);
++    double Y0 = (A3*B2 - A1*B3) / (A1*B1 - A2*B2);
+ 
+     wcsp->crpix[0] = (Xc - X0)/Rx - (CNPIX1 - 0.5);
+     wcsp->crpix[1] = (Yc + Y0)/Ry - (CNPIX2 - 0.5);
+@@ -2823,7 +2815,7 @@ int wcspih_final(
+     wcsp->cdelt[0] = -S/3600.0;
+     wcsp->cdelt[1] =  S/3600.0;
+ 
+-    crval = wcsp->crval;
++    double *crval = wcsp->crval;
+     crval[0] = (dsstmp[6]  + (dsstmp[7]  + dsstmp[8] /60.0)/60.0)*15.0;
+     crval[1] =  dsstmp[10] + (dsstmp[11] + dsstmp[12]/60.0)/60.0;
+     if (dsstmp[9] == -1.0) crval[1] *= -1.0;
+@@ -2833,19 +2825,23 @@ int wcspih_final(
  
      sprintf(wcsp->wcsname, "DSS PLATEID %.4s", (char *)(dsstmp+13));
  
@@ -31279,15 +36883,23 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
  
    } else if (distran == WAT) {
 -    /* TNX and ZPX don't have alternates, nor axis mapping. */
+-    disp = wcsp->lin.disseq;
 +    // TNX and ZPX don't have alternates, nor axis mapping.
-     disp = wcsp->lin.disseq;
++    char *wp;
++    int  omax, omin, wctrl[4];
++    double wval;
++    struct disprm *disp = wcsp->lin.disseq;
  
 -    /* Disassemble the core dump stored in the WATi_m strings. */
+-    nterms = 0;
 +    // Disassemble the core dump stored in the WATi_m strings.
-     nterms = 0;
++    int i, nterms = 0;
      for (i = 0; i < 2; i++) {
++      char wtype[8];
        sscanf(wat[i], "wtype=%s", wtype);
-@@ -2853,22 +2850,22 @@ int wcspih_final(
+ 
+       if (strcmp(wtype, "tnx") == 0) {
+@@ -2853,22 +2849,23 @@ int wcspih_final(
        } else if (strcmp(wtype, "zpx") == 0) {
          strcpy(disp->dtype[i], "WAT-ZPX");
        } else {
@@ -31302,9 +36914,11 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
        if (i == 1 && strcmp(wtype, "zpx") == 0) {
 -        /* Take those on the second (latitude) axis ignoring the other. */
 -        /* First we have to count them and allocate space in wcsprm.    */
+-        wp  = wat[i];
 +        // Take those on the second (latitude) axis ignoring the other.
 +        // First we have to count them and allocate space in wcsprm.
-         wp  = wat[i];
++        wp = wat[i];
++	int npv;
          for (npv = 0; npv < 30; npv++) {
            if ((wp = strstr(wp, "projp")) == 0x0) break;
            wp += 5;
@@ -31315,16 +36929,22 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
          if (npv) {
            wcsp->npvmax += npv;
            wcsp->pv = realloc(wcsp->pv, wcsp->npvmax*sizeof(struct pvcard));
-@@ -2879,7 +2876,7 @@ int wcspih_final(
+@@ -2879,11 +2876,12 @@ int wcspih_final(
            wcsp->m_pv = wcsp->pv;
          }
  
 -        /* Copy the values. */
 +        // Copy the values.
          wp = wat[i];
-         for (ipv = wcsp->npv; ipv < wcsp->npvmax; ipv++) {
+-        for (ipv = wcsp->npv; ipv < wcsp->npvmax; ipv++) {
++        for (int ipv = wcsp->npv; ipv < wcsp->npvmax; ipv++) {
            if ((wp = strstr(wp, "projp")) == 0x0) break;
-@@ -2895,7 +2892,7 @@ int wcspih_final(
+ 
++          int m;
+           sscanf(wp, "projp%d=%lf", &m, &wval);
+           wcsp->pv[ipv].i = 2;
+           wcsp->pv[ipv].m = m;
+@@ -2895,13 +2893,13 @@ int wcspih_final(
          wcsp->npv += npv;
        }
  
@@ -31333,7 +36953,14 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
        if ((wp = strchr(wat[i], '"')) == 0x0) {
          return WCSHDRERR_PARSER;
        }
-@@ -2909,24 +2906,24 @@ int wcspih_final(
+       wp++;
+ 
+-      for (m = 0; m < 4; m++) {
++      for (int m = 0; m < 4; m++) {
+         sscanf(wp, "%d", wctrl+m);
+         if ((wp = strchr(wp, ' ')) == 0x0) {
+           return WCSHDRERR_PARSER;
+@@ -2909,24 +2907,24 @@ int wcspih_final(
          wp++;
        }
  
@@ -31363,13 +36990,14 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
      ndq[0] += 2*(1 + 1 + 4) + nterms;
  
      disp->ndpmax += ndq[0];
-@@ -2938,12 +2935,12 @@ int wcspih_final(
+@@ -2938,18 +2936,18 @@ int wcspih_final(
      disp->m_dp = disp->dp;
  
  
 -    /* Populate dpkeys. */
+-    idp = disp->ndp;
 +    // Populate dpkeys.
-     idp = disp->ndp;
++    int idp = disp->ndp;
      for (i = 0; i < 2; i++) {
        dpfill(disp->dp+(idp++), "DQ", "NAXES", i+1, 0, 2, 0.0);
  
@@ -31378,12 +37006,20 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
        if ((wp = strchr(wat[i], '"')) == 0x0) {
          return WCSHDRERR_PARSER;
        }
-@@ -2957,23 +2954,23 @@ int wcspih_final(
+       wp++;
+ 
+-      for (m = 0; m < 4; m++) {
++      for (int m = 0; m < 4; m++) {
+         sscanf(wp, "%d", wctrl+m);
+         if ((wp = strchr(wp, ' ')) == 0x0) {
+           return WCSHDRERR_PARSER;
+@@ -2957,24 +2955,26 @@ int wcspih_final(
          wp++;
        }
  
 -      /* Polynomial type. */
 +      // Polynomial type.
++      char wpoly[12];
        dpfill(disp->dp+(idp++), "DQ", "WAT.POLY", i+1, 0, wctrl[0], 0.0);
        if (wctrl[0] == 1) {
 -        /* Chebyshev polynomial. */
@@ -31404,29 +37040,36 @@ Index: astropy-4.2/cextern/wcslib/C/wcspih.l
        }
  
 -      /* Read the scaling parameters. */
+-      for (m = 0; m < 4; m++) {
 +      // Read the scaling parameters.
-       for (m = 0; m < 4; m++) {
++      char field[40];
++      for (int m = 0; m < 4; m++) {
          sscanf(wp, "%lf", &wval);
          sprintf(field, "WAT.%c%s", (m<2)?'X':'Y', (m%2)?"MAX":"MIN");
-@@ -2985,7 +2982,7 @@ int wcspih_final(
+         dpfill(disp->dp+(idp++), "DQ", field, i+1, 1, 0, wval);
+@@ -2985,9 +2985,9 @@ int wcspih_final(
          wp++;
        }
  
 -      /* Read the coefficients. */
+-      for (n = 0; n < wctrl[2]; n++) {
+-        for (m = 0; m < wctrl[1]; m++) {
 +      // Read the coefficients.
-       for (n = 0; n < wctrl[2]; n++) {
-         for (m = 0; m < wctrl[1]; m++) {
++      for (int n = 0; n < wctrl[2]; n++) {
++        for (int m = 0; m < wctrl[1]; m++) {
            if (wctrl[3] == 0) {
-Index: astropy-4.2/cextern/wcslib/C/wcsprintf.c
+             if (m && n) continue;
+           } else if (wctrl[3] == 2) {
+Index: astropy-4.2.1/cextern/wcslib/C/wcsprintf.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcsprintf.c
-+++ astropy-4.2/cextern/wcslib/C/wcsprintf.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcsprintf.c
++++ astropy-4.2.1/cextern/wcslib/C/wcsprintf.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -31440,7 +37083,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsprintf.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcsprintf.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcsprintf.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcsprintf.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <stdarg.h>
@@ -31565,16 +37208,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcsprintf.c
        wcsprintf_size += 1024;
        realloc_buff = realloc(wcsprintf_buff, wcsprintf_size);
        if (realloc_buff == NULL) {
-Index: astropy-4.2/cextern/wcslib/C/wcsprintf.h
+Index: astropy-4.2.1/cextern/wcslib/C/wcsprintf.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcsprintf.h
-+++ astropy-4.2/cextern/wcslib/C/wcsprintf.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcsprintf.h
++++ astropy-4.2.1/cextern/wcslib/C/wcsprintf.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -31588,11 +37231,11 @@ Index: astropy-4.2/cextern/wcslib/C/wcsprintf.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcsprintf.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcsprintf.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcsprintf.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
@@ -31602,16 +37245,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcsprintf.h
  
 -#endif /* WCSLIB_WCSPRINTF */
 +#endif // WCSLIB_WCSPRINTF
-Index: astropy-4.2/cextern/wcslib/C/wcstrig.c
+Index: astropy-4.2.1/cextern/wcslib/C/wcstrig.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcstrig.c
-+++ astropy-4.2/cextern/wcslib/C/wcstrig.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcstrig.c
++++ astropy-4.2.1/cextern/wcslib/C/wcstrig.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -31625,7 +37268,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcstrig.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcstrig.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcstrig.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcstrig.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <math.h>
@@ -31692,16 +37335,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcstrig.c
  
  double atan2d(double y, double x)
  
-Index: astropy-4.2/cextern/wcslib/C/wcstrig.h
+Index: astropy-4.2.1/cextern/wcslib/C/wcstrig.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcstrig.h
-+++ astropy-4.2/cextern/wcslib/C/wcstrig.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcstrig.h
++++ astropy-4.2.1/cextern/wcslib/C/wcstrig.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -31715,11 +37358,11 @@ Index: astropy-4.2/cextern/wcslib/C/wcstrig.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcstrig.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcstrig.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcstrig.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
@@ -31759,16 +37402,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcstrig.h
  
 -#endif /* WCSLIB_WCSTRIG */
 +#endif // WCSLIB_WCSTRIG
-Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
+Index: astropy-4.2.1/cextern/wcslib/C/wcsulex.l
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcsulex.l
-+++ astropy-4.2/cextern/wcslib/C/wcsulex.l
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcsulex.l
++++ astropy-4.2.1/cextern/wcslib/C/wcsulex.l
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -31782,27 +37425,57 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcsulex.l,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcsulex.l,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcsulex.l,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
  * wcsulex.l is a Flex description file containing the definition of a
-@@ -98,7 +95,7 @@ static int wcsulex_scanner(const char un
-                            double units[WCSUNITS_NTYPE], struct wcserr **err,
-                            yyscan_t yyscanner);
+@@ -44,6 +41,7 @@
+ %option outfile="wcsulex.c"
+ %option prefix="wcsulex"
+ %option reentrant
++%option extra-type="struct wcsulex_extra *"
+ 
+ /* Exponents. */
+ INTEGER	  [+-]?[1-9][0-9]*
+@@ -94,81 +92,64 @@ ADD_UNIT  {ADD_ALL}|{ADD_SUP}|{ADD_SUB}|
+ #include "wcsunits.h"
+ #include "wcsutil.h"
+ 
+-static int wcsulex_scanner(const char unitstr[], int *func, double *scale,
+-                           double units[WCSUNITS_NTYPE], struct wcserr **err,
+-                           yyscan_t yyscanner);
+-
+-/*--------------------------------------------------------------------------*/
+-
+-int wcsulexe(
+-  const char unitstr[],
+-  int *func,
+-  double *scale,
+-  double units[WCSUNITS_NTYPE],
+-  struct wcserr **err)
+-
+-{
+-  int status;
+-  yyscan_t yyscanner;
+-  int yylex_init(yyscan_t *yyscanner);
+-  int yylex_destroy(yyscan_t yyscanner);
+-
+-  yylex_init(&yyscanner);
+-  status = wcsulex_scanner(unitstr, func, scale, units, err, yyscanner);
+-  yylex_destroy(yyscanner);
+-
+-  return status;
+-}
++// User data associated with yyscanner.
++struct wcsulex_extra {
++  // Used in preempting the call to exit() by yy_fatal_error().
++  jmp_buf abort_jmp_env;
++};
  
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
- 
- int wcsulexe(
-   const char unitstr[],
-@@ -120,16 +117,16 @@ int wcsulexe(
-   return status;
- }
- 
--/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
- 
- #define YY_DECL int wcsulex_scanner(const char unitstr[], int *func, \
+-
+-#define YY_DECL int wcsulex_scanner(const char unitstr[], int *func, \
++#define YY_DECL int wcsulexe_scanner(const char unitstr[], int *func, \
   double *scale, double units[WCSUNITS_NTYPE], struct wcserr **err, \
   yyscan_t yyscanner)
  
@@ -31811,13 +37484,58 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  #define YY_INPUT(inbuff, count, bufsize) { count = YY_NULL; }
  
 -/* Used in preempting the call to exit() by yy_fatal_error(). */
-+// Used in preempting the call to exit() by yy_fatal_error().
- jmp_buf wcsulex_abort_jmp_env;
- #define exit(status) longjmp(wcsulex_abort_jmp_env, status)
+-jmp_buf wcsulex_abort_jmp_env;
+-#define exit(status) longjmp(wcsulex_abort_jmp_env, status)
++// Preempt the call to exit() by yy_fatal_error().
++#define exit(status) longjmp(yyextra->abort_jmp_env, status);
++
++// Internal helper functions.
++static YY_DECL;
  
-@@ -160,14 +157,14 @@ jmp_buf wcsulex_abort_jmp_env;
- 	factor = 1.0;
- 	*scale = 1.0;
+ %}
+ 
+ %%
+-	static const char *function = "wcsulexe";
++	static const char *function = "wcsulexe_scanner";
+ 	
+-	char ctmp[72];
+-	int bracket  = 0;
+-	int operator = 0;
+-	int paren    = 0;
+-	int status   = 0;
+-	int func_r, i, j;
+-	double dexp, expon, factor, factor_r, types[WCSUNITS_NTYPE];
+-	YY_BUFFER_STATE buf;
+ 	void add(double *factor, double types[], double *expon, double *scale,
+ 	    double units[]);
+ 	
+-	if (err) *err = 0x0;
++	// Initialise returned values.
++	*func  = 0;
++	*scale = 1.0;
+ 	
+-	*func = 0;
+-	for (i = 0; i < WCSUNITS_NTYPE; i++) {
++	for (int i = 0; i < WCSUNITS_NTYPE; i++) {
+ 	  units[i] = 0.0;
++	}
++	
++	if (err) *err = 0x0;
++	
++	double types[WCSUNITS_NTYPE];
++	for (int i = 0; i < WCSUNITS_NTYPE; i++) {
+ 	  types[i] = 0.0;
+ 	}
+-	expon  = 1.0;
+-	factor = 1.0;
+-	*scale = 1.0;
++	double expon  = 1.0;
++	double factor = 1.0;
++	
++	int bracket  = 0;
++	int operator = 0;
++	int paren    = 0;
++	int status   = 0;
  	
 -	/* Avert a flex-induced memory leak. */
 +	// Avert a flex-induced memory leak.
@@ -31828,11 +37546,13 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	yy_scan_string(unitstr, yyscanner);
  	
 -	/* Return here via longjmp() invoked by yy_fatal_error(). */
+-	if (setjmp(wcsulex_abort_jmp_env)) {
 +	// Return here via longjmp() invoked by yy_fatal_error().
- 	if (setjmp(wcsulex_abort_jmp_env)) {
++	if (setjmp(yyextra->abort_jmp_env)) {
  	  return wcserr_set(WCSERR_SET(UNITSERR_PARSER_ERROR),
  	    "Internal units parser error parsing '%s'", unitstr);
-@@ -180,7 +177,7 @@ jmp_buf wcsulex_abort_jmp_env;
+ 	}
+@@ -180,7 +161,7 @@ jmp_buf wcsulex_abort_jmp_env;
  	#endif
  
  ^" "+	{
@@ -31841,7 +37561,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  yy_set_bol(1);
  	}
  
-@@ -222,13 +219,13 @@ jmp_buf wcsulex_abort_jmp_env;
+@@ -222,13 +203,13 @@ jmp_buf wcsulex_abort_jmp_env;
  	}
  
  ^[*.]	{
@@ -31857,7 +37577,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  
  sqrt" "*"(" {
  	  expon /= 2.0;
-@@ -237,7 +234,7 @@ sqrt" "*"(" {
+@@ -237,7 +218,7 @@ sqrt" "*"(" {
  	}
  
  "("	{
@@ -31866,7 +37586,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  yyless(0);
  	  BEGIN(PAREN);
  	}
-@@ -291,11 +288,11 @@ sqrt" "*"(" {
+@@ -291,15 +272,18 @@ sqrt" "*"(" {
  <PAREN>")" {
  	  paren--;
  	  if (paren) {
@@ -31879,8 +37599,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
 +	    // Balanced; strip off the outer parentheses and recurse.
  	    yytext[yyleng-1] = '\0';
  	
- 	    buf = YY_CURRENT_BUFFER;
-@@ -421,125 +418,125 @@ sqrt" "*"(" {
+-	    buf = YY_CURRENT_BUFFER;
++	    int func_r;
++	    double factor_r;
+ 	    status = wcsulexe(yytext+1, &func_r, &factor_r, types, err);
++	
++	    YY_BUFFER_STATE buf = YY_CURRENT_BUFFER;
+ 	    yy_switch_to_buffer(buf, yyscanner);
+ 	
+ 	    if (func_r) {
+@@ -421,125 +405,125 @@ sqrt" "*"(" {
  	}
  
  <PREFIX>. {
@@ -32025,7 +37753,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  factor *= 1e-29 / 3.0;
  	  types[WCSUNITS_CHARGE] += 1.0;
  	  types[WCSUNITS_LENGTH] += 1.0;
-@@ -547,20 +544,20 @@ sqrt" "*"(" {
+@@ -547,20 +531,20 @@ sqrt" "*"(" {
  	}
  
  <UNITS>d {
@@ -32049,7 +37777,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  factor *= 1e-7;
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
-@@ -569,7 +566,7 @@ sqrt" "*"(" {
+@@ -569,7 +553,7 @@ sqrt" "*"(" {
  	}
  
  <UNITS>eV {
@@ -32058,7 +37786,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  factor *= 1.6021765e-19;
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
-@@ -578,7 +575,7 @@ sqrt" "*"(" {
+@@ -578,7 +562,7 @@ sqrt" "*"(" {
  	}
  
  <UNITS>F {
@@ -32067,7 +37795,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  types[WCSUNITS_MASS]   -= 1.0;
  	  types[WCSUNITS_LENGTH] -= 2.0;
  	  types[WCSUNITS_TIME]   += 3.0;
-@@ -587,7 +584,7 @@ sqrt" "*"(" {
+@@ -587,7 +571,7 @@ sqrt" "*"(" {
  	}
  
  <UNITS>G {
@@ -32076,7 +37804,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  factor *= 1e-4;
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_TIME]   += 1.0;
-@@ -596,14 +593,14 @@ sqrt" "*"(" {
+@@ -596,14 +580,14 @@ sqrt" "*"(" {
  	}
  
  <UNITS>g {
@@ -32093,7 +37821,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
  	  types[WCSUNITS_TIME]   += 2.0;
-@@ -612,20 +609,20 @@ sqrt" "*"(" {
+@@ -612,20 +596,20 @@ sqrt" "*"(" {
  	}
  
  <UNITS>h {
@@ -32117,7 +37845,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
  	  types[WCSUNITS_TIME]   -= 2.0;
-@@ -633,7 +630,7 @@ sqrt" "*"(" {
+@@ -633,7 +617,7 @@ sqrt" "*"(" {
  	}
  
  <UNITS>Jy {
@@ -32126,7 +37854,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  factor *= 1e-26;
  	  types[WCSUNITS_MASS] += 1.0;
  	  types[WCSUNITS_TIME] -= 2.0;
-@@ -641,20 +638,20 @@ sqrt" "*"(" {
+@@ -641,20 +625,20 @@ sqrt" "*"(" {
  	}
  
  <UNITS>K {
@@ -32150,7 +37878,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  types[WCSUNITS_LUMINTEN]    += 1.0;
  	  types[WCSUNITS_SOLID_ANGLE] += 1.0;
  	  types[WCSUNITS_LENGTH]      -= 2.0;
-@@ -662,46 +659,46 @@ sqrt" "*"(" {
+@@ -662,46 +646,46 @@ sqrt" "*"(" {
  	}
  
  <UNITS>lyr {
@@ -32204,7 +37932,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 1.0;
  	  types[WCSUNITS_TIME]   -= 2.0;
-@@ -709,7 +706,7 @@ sqrt" "*"(" {
+@@ -709,7 +693,7 @@ sqrt" "*"(" {
  	}
  
  <UNITS>[Oo]hm {
@@ -32213,7 +37941,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
  	  types[WCSUNITS_TIME]   -= 1.0;
-@@ -718,7 +715,7 @@ sqrt" "*"(" {
+@@ -718,7 +702,7 @@ sqrt" "*"(" {
  	}
  
  <UNITS>Pa {
@@ -32222,7 +37950,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] -= 1.0;
  	  types[WCSUNITS_TIME]   -= 2.0;
-@@ -726,26 +723,26 @@ sqrt" "*"(" {
+@@ -726,26 +710,26 @@ sqrt" "*"(" {
  	}
  
  <UNITS>pc {
@@ -32253,7 +37981,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  factor *= 1e10 / (4.0 * PI);
  	  types[WCSUNITS_LENGTH]      -= 2.0;
  	  types[WCSUNITS_TIME]        -= 1.0;
-@@ -754,14 +751,14 @@ sqrt" "*"(" {
+@@ -754,14 +738,14 @@ sqrt" "*"(" {
  	}
  
  <UNITS>rad {
@@ -32270,7 +37998,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  factor *= 13.605692 * 1.6021765e-19;
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
-@@ -770,7 +767,7 @@ sqrt" "*"(" {
+@@ -770,7 +754,7 @@ sqrt" "*"(" {
  	}
  
  <UNITS>S {
@@ -32279,7 +38007,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  types[WCSUNITS_MASS]   -= 1.0;
  	  types[WCSUNITS_LENGTH] -= 2.0;
  	  types[WCSUNITS_TIME]   += 1.0;
-@@ -779,13 +776,13 @@ sqrt" "*"(" {
+@@ -779,13 +763,13 @@ sqrt" "*"(" {
  	}
  
  <UNITS>s {
@@ -32295,7 +38023,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  factor *= 3.8268e26;
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
-@@ -794,33 +791,33 @@ sqrt" "*"(" {
+@@ -794,33 +778,33 @@ sqrt" "*"(" {
  	}
  
  <UNITS>solMass {
@@ -32334,7 +38062,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_TIME]   += 1.0;
  	  types[WCSUNITS_CHARGE] -= 1.0;
-@@ -828,21 +825,21 @@ sqrt" "*"(" {
+@@ -828,21 +812,21 @@ sqrt" "*"(" {
  	}
  
  <UNITS>turn {
@@ -32359,7 +38087,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 1.0;
  	  types[WCSUNITS_TIME]   -= 2.0;
-@@ -851,13 +848,13 @@ sqrt" "*"(" {
+@@ -851,13 +835,13 @@ sqrt" "*"(" {
  	}
  
  <UNITS>voxel {
@@ -32375,7 +38103,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
  	  types[WCSUNITS_TIME]   -= 3.0;
-@@ -865,7 +862,7 @@ sqrt" "*"(" {
+@@ -865,7 +849,7 @@ sqrt" "*"(" {
  	}
  
  <UNITS>Wb {
@@ -32384,7 +38112,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  types[WCSUNITS_MASS]   += 1.0;
  	  types[WCSUNITS_LENGTH] += 2.0;
  	  types[WCSUNITS_TIME]   += 1.0;
-@@ -874,14 +871,14 @@ sqrt" "*"(" {
+@@ -874,20 +858,21 @@ sqrt" "*"(" {
  	}
  
  <UNITS>. {
@@ -32401,7 +38129,40 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  if (operator++) {
  	    BEGIN(FLUSH);
  	  }
-@@ -921,7 +918,7 @@ sqrt" "*"(" {
+ 	}
+ 
+ <EXPON>" "*{INTEGER} {
++	  int i;
+ 	  sscanf(yytext, " %d", &i);
+ 	  expon *= (double)i;
+ 	  add(&factor, types, &expon, scale, units);
+@@ -896,6 +881,7 @@ sqrt" "*"(" {
+ 	}
+ 
+ <EXPON>" "*"("" "*{INTEGER}" "*")" {
++	  int i;
+ 	  sscanf(yytext, " (%d)", &i);
+ 	  expon *= (double)i;
+ 	  add(&factor, types, &expon, scale, units);
+@@ -904,6 +890,7 @@ sqrt" "*"(" {
+ 	}
+ 
+ <EXPON>" "*"("" "*{FRAC}" "*")" {
++	  int i, j;
+ 	  sscanf(yytext, " (%d/%d)", &i, &j);
+ 	  expon *= (double)i / (double)j;
+ 	  add(&factor, types, &expon, scale, units);
+@@ -912,7 +899,9 @@ sqrt" "*"(" {
+ 	}
+ 
+ <EXPON>" "*"("" "*{FLOAT}" "*")" {
++	  char ctmp[72];
+ 	  sscanf(yytext, " (%s)", ctmp);
++	  double dexp;
+ 	  wcsutil_str2double(ctmp, &dexp);
+ 	  expon *= dexp;
+ 	  add(&factor, types, &expon, scale, units);
+@@ -921,7 +910,7 @@ sqrt" "*"(" {
  	}
  
  <EXPON>" "*[.*]" "* {
@@ -32410,7 +38171,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  if (operator++) {
  	    BEGIN(FLUSH);
  	  } else {
-@@ -931,7 +928,7 @@ sqrt" "*"(" {
+@@ -931,7 +920,7 @@ sqrt" "*"(" {
  	}
  
  <EXPON>" "*"(" {
@@ -32419,7 +38180,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  if (operator) {
  	    BEGIN(FLUSH);
  	  } else {
-@@ -942,7 +939,7 @@ sqrt" "*"(" {
+@@ -942,7 +931,7 @@ sqrt" "*"(" {
  	}
  
  <EXPON>" "+ {
@@ -32428,7 +38189,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  if (operator) {
  	    BEGIN(FLUSH);
  	  } else {
-@@ -952,7 +949,7 @@ sqrt" "*"(" {
+@@ -952,7 +941,7 @@ sqrt" "*"(" {
  	}
  
  <EXPON>" "*"/"" "* {
@@ -32437,7 +38198,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  if (operator++) {
  	    BEGIN(FLUSH);
  	  } else {
-@@ -975,11 +972,11 @@ sqrt" "*"(" {
+@@ -975,11 +964,11 @@ sqrt" "*"(" {
  	}
  
  <FLUSH>.* {
@@ -32451,16 +38212,73 @@ Index: astropy-4.2/cextern/wcslib/C/wcsulex.l
  	  if (YY_START == EXPON) {
  	    add(&factor, types, &expon, scale, units);
  	  }
-Index: astropy-4.2/cextern/wcslib/C/wcsunits.c
+@@ -1003,7 +992,7 @@ sqrt" "*"(" {
+ 	  }
+ 	
+ 	  if (status) {
+-	    for (i = 0; i < WCSUNITS_NTYPE; i++) {
++	    for (int i = 0; i < WCSUNITS_NTYPE; i++) {
+ 	      units[i] = 0.0;
+ 	      *scale = 0.0;
+ 	    }
+@@ -1015,6 +1004,34 @@ sqrt" "*"(" {
+ %%
+ 
+ /*----------------------------------------------------------------------------
++* External interface to the scanner.
++*---------------------------------------------------------------------------*/
++
++int wcsulexe(
++  const char unitstr[],
++  int *func,
++  double *scale,
++  double units[WCSUNITS_NTYPE],
++  struct wcserr **err)
++
++{
++  static const char *function = "wcsulexe";
++
++  // Function prototypes.
++  int yylex_init_extra(YY_EXTRA_TYPE extra, yyscan_t *yyscanner);
++  int yylex_destroy(yyscan_t yyscanner);
++
++  struct wcsulex_extra extra;
++  yyscan_t yyscanner;
++  yylex_init_extra(&extra, &yyscanner);
++  int status = wcsulexe_scanner(unitstr, func, scale, units, err, yyscanner);
++  yylex_destroy(yyscanner);
++
++  return status;
++}
++
++
++/*----------------------------------------------------------------------------
+ * Accumulate a term in a units specification and reset work variables.
+ *---------------------------------------------------------------------------*/
+ 
+@@ -1026,11 +1043,9 @@ void add(
+   double units[])
+ 
+ {
+-  int i;
+-
+   *scale *= pow(*factor, *expon);
+ 
+-  for (i = 0; i < WCSUNITS_NTYPE; i++) {
++  for (int i = 0; i < WCSUNITS_NTYPE; i++) {
+     units[i] += *expon * types[i];
+     types[i] = 0.0;
+   }
+Index: astropy-4.2.1/cextern/wcslib/C/wcsunits.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcsunits.c
-+++ astropy-4.2/cextern/wcslib/C/wcsunits.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcsunits.c
++++ astropy-4.2.1/cextern/wcslib/C/wcsunits.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -32474,7 +38292,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsunits.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcsunits.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcsunits.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcsunits.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <math.h>
@@ -32603,16 +38421,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcsunits.c
  
  int wcsulex(const char unitstr[], int *func, double *scale, double units[])
  
-Index: astropy-4.2/cextern/wcslib/C/wcsunits.h
+Index: astropy-4.2.1/cextern/wcslib/C/wcsunits.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcsunits.h
-+++ astropy-4.2/cextern/wcslib/C/wcsunits.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcsunits.h
++++ astropy-4.2.1/cextern/wcslib/C/wcsunits.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -32626,11 +38444,11 @@ Index: astropy-4.2/cextern/wcslib/C/wcsunits.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcsunits.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcsunits.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcsunits.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
@@ -32765,16 +38583,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcsunits.h
  
 -#endif /* WCSLIB_WCSUNITS */
 +#endif // WCSLIB_WCSUNITS
-Index: astropy-4.2/cextern/wcslib/C/wcsutil.c
+Index: astropy-4.2.1/cextern/wcslib/C/wcsutil.c
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcsutil.c
-+++ astropy-4.2/cextern/wcslib/C/wcsutil.c
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcsutil.c
++++ astropy-4.2.1/cextern/wcslib/C/wcsutil.c
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -32788,7 +38606,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutil.c
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcsutil.c,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcsutil.c,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcsutil.c,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *===========================================================================*/
  
  #include <ctype.h>
@@ -32801,47 +38619,91 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutil.c
  
  void wcsdealloc(void *ptr)
  
-@@ -45,7 +42,7 @@ void wcsdealloc(void *ptr)
+@@ -45,74 +42,71 @@ void wcsdealloc(void *ptr)
    return;
  }
  
 -/*--------------------------------------------------------------------------*/
 +//----------------------------------------------------------------------------
  
- void wcsutil_strcvt(int n, char c, const char src[], char dst[])
+-void wcsutil_strcvt(int n, char c, const char src[], char dst[])
++void wcsutil_strcvt(int n, char c, int nt, const char src[], char dst[])
  
-@@ -64,7 +61,7 @@ void wcsutil_strcvt(int n, char c, const
-     return;
-   }
+ {
+-  int j;
+-
+   if (n <= 0) return;
  
+   if (c != '\0') c = ' ';
+ 
+   if (src == 0x0) {
+     if (dst) {
+-       memset(dst, c, n);
++      memset(dst, c, n);
+     }
+ 
+-    return;
+-  }
+-
 -  /* Copy to the first NULL character. */
-+  // Copy to the first NULL character.
-   for (j = 0; j < n; j++) {
-     if ((dst[j] = src[j]) == '\0') {
-       break;
-@@ -72,18 +69,18 @@ void wcsutil_strcvt(int n, char c, const
+-  for (j = 0; j < n; j++) {
+-    if ((dst[j] = src[j]) == '\0') {
+-      break;
++  } else {
++    // Copy to the first NULL character.
++    int j;
++    for (j = 0; j < n; j++) {
++      if ((dst[j] = src[j]) == '\0') {
++        break;
++      }
+     }
+-  }
+-
+-  if (j < n) {
+-    /* The given string is null-terminated. */
+-    memset(dst+j, c, n-j);
+ 
+-  } else {
+-    /* The given string is not null-terminated. */
+-    if (c == '\0') {
+-      j = n - 1;
+-      dst[j] = '\0';
+-
+-      j--;
+-
+-      /* Work backwards, looking for the first non-blank. */
+-      for (; j >= 0; j--) {
+-        if (dst[j] != ' ') {
+-          break;
++    if (j < n) {
++      // The given string is null-terminated.
++      memset(dst+j, c, n-j);
++
++    } else {
++      // The given string is not null-terminated.
++      if (c == '\0') {
++        // Work backwards, looking for the first non-blank.
++        for (j = n - 1; j >= 0; j--) {
++          if (dst[j] != ' ') {
++            break;
++          }
+         }
+-      }
+ 
+-      j++;
+-      memset(dst+j, '\0', n-j);
++        j++;
++	if (j == n && !nt) {
++	  dst[n-1] = '\0';
++	} else {
++          memset(dst+j, '\0', n-j);
++	}
++      }
+     }
    }
  
-   if (j < n) {
--    /* The given string is null-terminated. */
-+    // The given string is null-terminated.
-     memset(dst+j, c, n-j);
- 
-   } else {
--    /* The given string is not null-terminated. */
-+    // The given string is not null-terminated.
-     if (c == '\0') {
-       j = n - 1;
-       dst[j] = '\0';
- 
-       j--;
- 
--      /* Work backwards, looking for the first non-blank. */
-+      // Work backwards, looking for the first non-blank.
-       for (; j >= 0; j--) {
-         if (dst[j] != ' ') {
-           break;
-@@ -98,7 +95,7 @@ void wcsutil_strcvt(int n, char c, const
++  if (nt) dst[n] = '\0';
++
    return;
  }
  
@@ -32850,16 +38712,23 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutil.c
  
  void wcsutil_blank_fill(int n, char c[])
  
-@@ -111,7 +108,7 @@ void wcsutil_blank_fill(int n, char c[])
+ {
+-  int j;
+-
+   if (n <= 0) return;
+ 
+   if (c == 0x0) {
      return;
    }
  
 -  /* Replace the terminating null and all successive characters. */
+-  for (j = 0; j < n; j++) {
 +  // Replace the terminating null and all successive characters.
-   for (j = 0; j < n; j++) {
++  for (int j = 0; j < n; j++) {
      if (c[j] == '\0') {
        memset(c+j, ' ', n-j);
-@@ -122,7 +119,7 @@ void wcsutil_blank_fill(int n, char c[])
+       break;
+@@ -122,33 +116,32 @@ void wcsutil_blank_fill(int n, char c[])
    return;
  }
  
@@ -32868,12 +38737,18 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutil.c
  
  void wcsutil_null_fill(int n, char c[])
  
-@@ -135,20 +132,20 @@ void wcsutil_null_fill(int n, char c[])
+ {
+-  int j;
+-
+   if (n <= 0) return;
+ 
+   if (c == 0x0) {
      return;
    }
  
 -  /* Find the first NULL character. */
 +  // Find the first NULL character.
++  int j;
    for (j = 0; j < n; j++) {
      if (c[j] == '\0') {
        break;
@@ -32892,65 +38767,179 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutil.c
    j--;
    for (; j > 0; j--) {
      if (c[j] != ' ') {
-@@ -163,7 +160,7 @@ void wcsutil_null_fill(int n, char c[])
+@@ -163,174 +156,211 @@ void wcsutil_null_fill(int n, char c[])
    return;
  }
  
 -/*--------------------------------------------------------------------------*/
 +//----------------------------------------------------------------------------
  
- int wcsutil_allEq(int nvec, int nelem, const double *first)
+-int wcsutil_allEq(int nvec, int nelem, const double *first)
++int wcsutil_all_ival(int nelem, int ival, const int iarr[])
++
++{
++  for (int i = 0; i < nelem; i++) {
++    if (iarr[i] != ival) return 0;
++  }
++
++  return 1;
++}
++
++//----------------------------------------------------------------------------
++
++int wcsutil_all_dval(int nelem, double dval, const double darr[])
++
++{
++  for (int i = 0; i < nelem; i++) {
++    if (darr[i] != dval) return 0;
++  }
++
++  return 1;
++}
++
++//----------------------------------------------------------------------------
++
++int wcsutil_all_sval(int nelem, const char *sval, const char (*sarr)[72])
+ 
+ {
+-  double v0;
+-  const double *vp;
++  for (int i = 0; i < nelem; i++) {
++    if (strncmp(sarr[i], sval, 72)) return 0;
++  }
+ 
++  return 1;
++}
++
++//----------------------------------------------------------------------------
++
++int wcsutil_allEq(int nvec, int nelem, const double *first)
++
++{
+   if (nvec <= 0 || nelem <= 0) return 0;
+ 
+-  v0 = *first;
+-  for (vp = first+nelem; vp < first + nvec*nelem; vp += nelem) {
++  double v0 = *first;
++  for (const double *vp = first+nelem; vp < first + nvec*nelem; vp += nelem) {
+     if (*vp != v0) return 0;
+   }
  
-@@ -181,7 +178,7 @@ int wcsutil_allEq(int nvec, int nelem, c
    return 1;
  }
  
 -/*--------------------------------------------------------------------------*/
 +//----------------------------------------------------------------------------
  
- int wcsutil_Eq(int nelem, double tol, const double *arr1, const double *arr2)
+-int wcsutil_Eq(int nelem, double tol, const double *arr1, const double *arr2)
++int wcsutil_dblEq(
++  int nelem,
++  double tol,
++  const double *darr1,
++  const double *darr2)
  
-@@ -195,18 +192,18 @@ int wcsutil_Eq(int nelem, double tol, co
-   if (arr1 == 0x0 || arr2 == 0x0) return 0;
+ {
+-  int i;
+-
+   if (nelem == 0) return 1;
+   if (nelem  < 0) return 0;
+ 
+-  if (arr1 == 0x0 && arr2 == 0x0) return 1;
+-  if (arr1 == 0x0 || arr2 == 0x0) return 0;
++  if (darr1 == 0x0 && darr2 == 0x0) return 1;
  
    if (tol == 0.0) {
 -    /* Handled separately for speed of execution. */
+-    for (i = 0; i < nelem; i++, arr1++, arr2++) {
+-      if (*arr1 != *arr2) return 0;
 +    // Handled separately for speed of execution.
-     for (i = 0; i < nelem; i++, arr1++, arr2++) {
-       if (*arr1 != *arr2) return 0;
++    for (int i = 0; i < nelem; i++) {
++      double dval1 = (darr1 ? darr1[i] : UNDEFINED);
++      double dval2 = (darr2 ? darr2[i] : UNDEFINED);
++
++      // Undefined values must match exactly.
++      if (dval1 == UNDEFINED && dval2 != UNDEFINED) return 0;
++      if (dval1 != UNDEFINED && dval2 == UNDEFINED) return 0;
++
++      if (dval1 != dval2) return 0;
      }
  
    } else {
-     for (i = 0; i < nelem; i++, arr1++, arr2++) {
+-    for (i = 0; i < nelem; i++, arr1++, arr2++) {
 -      /* Undefined values must match exactly. */
+-      if (*arr1 == UNDEFINED && *arr2 != UNDEFINED) return 0;
+-      if (*arr1 != UNDEFINED && *arr2 == UNDEFINED) return 0;
++    for (int i = 0; i < nelem; i++) {
++      double dval1 = (darr1 ? darr1[i] : UNDEFINED);
++      double dval2 = (darr2 ? darr2[i] : UNDEFINED);
++
 +      // Undefined values must match exactly.
-       if (*arr1 == UNDEFINED && *arr2 != UNDEFINED) return 0;
-       if (*arr1 != UNDEFINED && *arr2 == UNDEFINED) return 0;
++      if (dval1 == UNDEFINED && dval2 != UNDEFINED) return 0;
++      if (dval1 != UNDEFINED && dval2 == UNDEFINED) return 0;
  
 -      /* Otherwise, compare within the specified tolerance. */
+-      if (fabs(*arr1 - *arr2) > 0.5*tol) return 0;
 +      // Otherwise, compare within the specified tolerance.
-       if (fabs(*arr1 - *arr2) > 0.5*tol) return 0;
++      if (fabs(dval1 - dval2) > 0.5*tol) return 0;
      }
    }
-@@ -214,7 +211,7 @@ int wcsutil_Eq(int nelem, double tol, co
+ 
    return 1;
  }
  
 -/*--------------------------------------------------------------------------*/
 +//----------------------------------------------------------------------------
  
- int wcsutil_intEq(int nelem, const int *arr1, const int *arr2)
+-int wcsutil_intEq(int nelem, const int *arr1, const int *arr2)
++int wcsutil_intEq(int nelem, const int *iarr1, const int *iarr2)
+ 
+ {
+-  int i;
+-
+   if (nelem == 0) return 1;
+   if (nelem  < 0) return 0;
+ 
+-  if (arr1 == 0x0 && arr2 == 0x0) return 1;
+-  if (arr1 == 0x0 || arr2 == 0x0) return 0;
++  if (iarr1 == 0x0 && iarr2 == 0x0) return 1;
++
++  for (int i = 0; i < nelem; i++) {
++    int ival1 = (iarr1 ?  iarr1[i] : 0);
++    int ival2 = (iarr2 ?  iarr2[i] : 0);
+ 
+-  for (i = 0; i < nelem; i++, arr1++, arr2++) {
+-    if (*arr1 != *arr2) return 0;
++    if (ival1 != ival2) return 0;
+   }
  
-@@ -234,7 +231,7 @@ int wcsutil_intEq(int nelem, const int *
    return 1;
  }
  
 -/*--------------------------------------------------------------------------*/
 +//----------------------------------------------------------------------------
  
- int wcsutil_strEq(int nelem, char (*arr1)[72], char (*arr2)[72])
+-int wcsutil_strEq(int nelem, char (*arr1)[72], char (*arr2)[72])
++int wcsutil_strEq(int nelem, char (*sarr1)[72], char (*sarr2)[72])
+ 
+ {
+-  int i;
+-
+   if (nelem == 0) return 1;
+   if (nelem  < 0) return 0;
+ 
+-  if (arr1 == 0x0 && arr2 == 0x0) return 1;
+-  if (arr1 == 0x0 || arr2 == 0x0) return 0;
++  if (sarr1 == 0x0 && sarr2 == 0x0) return 1;
++
++  for (int i = 0; i < nelem; i++) {
++    char *sval1 = (sarr1 ?  sarr1[i] : "");
++    char *sval2 = (sarr2 ?  sarr2[i] : "");
+ 
+-  for (i = 0; i < nelem; i++, arr1++, arr2++) {
+-    if (strncmp(*arr1, *arr2, 72)) return 0;
++    if (strncmp(sval1, sval2, 72)) return 0;
+   }
  
-@@ -254,7 +251,7 @@ int wcsutil_strEq(int nelem, char (*arr1
    return 1;
  }
  
@@ -32959,7 +38948,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutil.c
  
  void wcsutil_setAll(int nvec, int nelem, double *first)
  
-@@ -269,7 +266,7 @@ void wcsutil_setAll(int nvec, int nelem,
+ {
+-  double v0, *vp;
+-
+   if (nvec <= 0 || nelem <= 0) return;
+ 
+-  v0 = *first;
+-  for (vp = first+nelem; vp < first + nvec*nelem; vp += nelem) {
++  double v0 = *first;
++  for (double *vp = first+nelem; vp < first + nvec*nelem; vp += nelem) {
+     *vp = v0;
    }
  }
  
@@ -32968,7 +38966,16 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutil.c
  
  void wcsutil_setAli(int nvec, int nelem, int *first)
  
-@@ -284,7 +281,7 @@ void wcsutil_setAli(int nvec, int nelem,
+ {
+-  int v0, *vp;
+-
+   if (nvec <= 0 || nelem <= 0) return;
+ 
+-  v0 = *first;
+-  for (vp = first+nelem; vp < first + nvec*nelem; vp += nelem) {
++  int v0 = *first;
++  for (int *vp = first+nelem; vp < first + nvec*nelem; vp += nelem) {
+     *vp = v0;
    }
  }
  
@@ -32977,20 +38984,24 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutil.c
  
  void wcsutil_setBit(int nelem, const int *sel, int bits, int *array)
  
-@@ -294,20 +291,20 @@ void wcsutil_setBit(int nelem, const int
+ {
+-  int *arrp;
+-
    if (bits == 0 || nelem <= 0) return;
  
    if (sel == 0x0) {
 -    /* All elements selected. */
+-    for (arrp = array; arrp < array + nelem; arrp++) {
 +    // All elements selected.
-     for (arrp = array; arrp < array + nelem; arrp++) {
++    for (int *arrp = array; arrp < array + nelem; arrp++) {
        *arrp |= bits;
      }
  
    } else {
 -    /* Some elements selected. */
+-    for (arrp = array; arrp < array + nelem; arrp++) {
 +    // Some elements selected.
-     for (arrp = array; arrp < array + nelem; arrp++) {
++    for (int *arrp = array; arrp < array + nelem; arrp++) {
        if (*(sel++)) *arrp |= bits;
      }
    }
@@ -33001,30 +39012,38 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutil.c
  
  char *wcsutil_fptr2str(void (*fptr)(void), char hext[19])
  
-@@ -317,11 +314,11 @@ char *wcsutil_fptr2str(void (*fptr)(void
-   unsigned int i;
-   int *(ip[2]), j[2], le = 1, gotone = 0;
- 
+ {
+-  unsigned char *p = (unsigned char *)(&fptr);
+-  char *t = hext;
+-  unsigned int i;
+-  int *(ip[2]), j[2], le = 1, gotone = 0;
+-
 -  /* Test for little-endian addresses. */
 +  // Test for little-endian addresses.
++  int *(ip[2]), j[2], le = 1;
    ip[0] = j;
    ip[1] = j + 1;
++  unsigned char *p = (unsigned char *)(&fptr);
    if ((unsigned char *)ip[0] < (unsigned char *)ip[1]) {
 -    /* Little-endian, reverse it. */
 +    // Little-endian, reverse it.
      p += sizeof(fptr) - 1;
      le = -1;
    }
-@@ -330,7 +327,7 @@ char *wcsutil_fptr2str(void (*fptr)(void
+ 
++  char *t = hext;
+   sprintf(t, "0x0");
    t += 2;
  
-   for (i = 0; i < sizeof(fptr); i++) {
+-  for (i = 0; i < sizeof(fptr); i++) {
 -    /* Skip leading zeroes. */
++  for (size_t i = 0; i < sizeof(fptr); i++) {
 +    // Skip leading zeroes.
++    int gotone = 0;
      if (*p) gotone = 1;
  
      if (gotone) {
-@@ -344,7 +341,7 @@ char *wcsutil_fptr2str(void (*fptr)(void
+@@ -344,7 +374,7 @@ char *wcsutil_fptr2str(void (*fptr)(void
    return hext;
  }
  
@@ -33033,16 +39052,23 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutil.c
  
  static void wcsutil_locale_to_dot(char *buf)
  
-@@ -379,7 +376,7 @@ void wcsutil_double2str(char *buf, const
+@@ -374,13 +404,11 @@ static void wcsutil_locale_to_dot(char *
+ void wcsutil_double2str(char *buf, const char *format, double value)
+ 
+ {
+-  char *bp, *cp;
+-
    sprintf(buf, format, value);
    wcsutil_locale_to_dot(buf);
  
 -  /* Look for a decimal point or exponent. */
+-  bp = buf;
 +  // Look for a decimal point or exponent.
-   bp = buf;
++  char *bp = buf;
    while (*bp) {
      if (*bp != ' ') {
-@@ -390,7 +387,7 @@ void wcsutil_double2str(char *buf, const
+       if (*bp == '.') return;
+@@ -390,10 +418,10 @@ void wcsutil_double2str(char *buf, const
      bp++;
    }
  
@@ -33050,8 +39076,12 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutil.c
 +  // Not found, add a fractional part.
    bp = buf;
    if (*bp == ' ') {
-     cp = buf + 1;
-@@ -408,7 +405,7 @@ void wcsutil_double2str(char *buf, const
+-    cp = buf + 1;
++    char *cp = buf + 1;
+     if (*cp == ' ') cp++;
+ 
+     while (*cp) {
+@@ -408,7 +436,7 @@ void wcsutil_double2str(char *buf, const
    }
  }
  
@@ -33060,38 +39090,50 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutil.c
  
  static const char *wcsutil_dot_to_locale(const char *inbuf, char *outbuf)
  
-@@ -455,7 +452,7 @@ int wcsutil_str2double2(const char *buf,
+@@ -449,24 +477,24 @@ int wcsutil_str2double(const char *buf,
+ int wcsutil_str2double2(const char *buf, double *value)
+ 
+ {
+-  char   *cptr, ctmp[72], *dptr, *eptr, ltmp[72];
+-  int    exp = 0;
+-
    value[0] = 0.0;
    value[1] = 0.0;
  
 -  /* Get the integer part. */
 +  // Get the integer part.
++  char ltmp[72];
    if (sscanf(wcsutil_dot_to_locale(buf, ltmp), "%lf", value) < 1) {
      return 1;
    }
-@@ -463,10 +460,10 @@ int wcsutil_str2double2(const char *buf,
+   value[0] = floor(value[0]);
  
++  char ctmp[72];
    strcpy(ctmp, buf);
  
 -  /* Look for a decimal point. */
+-  dptr = strchr(ctmp, '.');
 +  // Look for a decimal point.
-   dptr = strchr(ctmp, '.');
++  char *dptr = strchr(ctmp, '.');
  
 -  /* Look for an exponent. */
 +  // Look for an exponent.
++  char *eptr;
    if ((eptr = strchr(ctmp, 'E')) == NULL) {
      if ((eptr = strchr(ctmp, 'D')) == NULL) {
        if ((eptr = strchr(ctmp, 'e')) == NULL) {
-@@ -476,7 +473,7 @@ int wcsutil_str2double2(const char *buf,
+@@ -475,8 +503,9 @@ int wcsutil_str2double2(const char *buf,
+     }
    }
  
++  int exp = 0;
    if (eptr) {
 -    /* Get the exponent. */
 +    // Get the exponent.
      if (sscanf(eptr+1, "%d", &exp) < 1) {
        return 1;
      }
-@@ -487,15 +484,15 @@ int wcsutil_str2double2(const char *buf,
+@@ -487,17 +516,17 @@ int wcsutil_str2double2(const char *buf,
      }
  
      if (dptr+exp <= ctmp) {
@@ -33108,18 +39150,21 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutil.c
 -  /* Get the fractional part. */
 +  // Get the fractional part.
    if (dptr) {
-     cptr = ctmp;
+-    cptr = ctmp;
++    char *cptr = ctmp;
      while (cptr <= dptr+exp) {
-Index: astropy-4.2/cextern/wcslib/C/wcsutil.h
+       if ('0' < *cptr && *cptr <= '9') *cptr = '0';
+       cptr++;
+Index: astropy-4.2.1/cextern/wcslib/C/wcsutil.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcsutil.h
-+++ astropy-4.2/cextern/wcslib/C/wcsutil.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcsutil.h
++++ astropy-4.2.1/cextern/wcslib/C/wcsutil.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -33133,30 +39178,197 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutil.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcsutil.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcsutil.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcsutil.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
-@@ -428,4 +425,4 @@ int  wcsutil_str2double2(const char *buf
+@@ -67,9 +64,10 @@
+ * wcsutil_strcvt() copies one character string to another up to the specified
+ * maximum number of characters.
+ *
+-* If the given string is null-terminated, then the terminating NULL character,
+-* and all characters following it up to the specified maximum, are replaced
+-* with the specified substitute character, either blank or NULL.
++* If the given string is null-terminated, then the NULL character copied to
++* the returned string, and all characters following it up to the specified
++* maximum, are replaced with the specified substitute character, either blank
++* or NULL.
+ *
+ * If the source string is not null-terminated and the substitute character is
+ * blank, then copy the maximum number of characters and do nothing further.
+@@ -85,9 +83,11 @@
+ *   c         char      Substitute character, either NULL or blank (anything
+ *                       other than NULL).
+ *
+-*   src       const char[]
+-*                       Character string to be copied.  Need not be
+-*                       null-terminated.
++*   nt        int       If true, then dst is of length n+1, with the last
++*                       character always set to NULL.
++*
++*   src       char[]    Character string to be copied.  If null-terminated,
++*                       then need not be of length n, otherwise it must be.
+ *
+ * Returned:
+ *   dst       char[]    Destination character string, which must be long
+@@ -142,6 +142,69 @@
+ *             void
+ *
+ *
++* wcsutil_all_ival() - Test if all elements an int array have a given value
++* -------------------------------------------------------------------------
++* INTERNAL USE ONLY.
++*
++* wcsutil_all_ival() tests whether all elements of an array of type int all
++* have the specified value.
++*
++* Given:
++*   nelem     int       The length of the array.
++*
++*   ival      int       Value to be tested.
++*
++*   iarr      const int[]
++*                       Pointer to the first element of the array.
++*
++* Function return value:
++*             int       Status return value:
++*                         0: Not all equal.
++*                         1: All equal.
++*
++*
++* wcsutil_all_dval() - Test if all elements a double array have a given value
++* ---------------------------------------------------------------------------
++* INTERNAL USE ONLY.
++*
++* wcsutil_all_dval() tests whether all elements of an array of type double all
++* have the specified value.
++*
++* Given:
++*   nelem     int       The length of the array.
++*
++*   dval      int       Value to be tested.
++*
++*   darr      const double[]
++*                       Pointer to the first element of the array.
++*
++* Function return value:
++*             int       Status return value:
++*                         0: Not all equal.
++*                         1: All equal.
++*
++*
++* wcsutil_all_sval() - Test if all elements a string array have a given value
++* ---------------------------------------------------------------------------
++* INTERNAL USE ONLY.
++*
++* wcsutil_all_sval() tests whether all elements of an array of type
++* char (*)[72] all have the specified value.
++*
++* Given:
++*   nelem     int       The length of the array.
++*
++*   sval      char *    String to be tested.
++*
++*   sarr      const (*char)[72]
++*                       Pointer to the first element of the array.
++*
++* Function return value:
++*             int       Status return value:
++*                         0: Not all equal.
++*                         1: All equal.
++*
++*
+ * wcsutil_allEq() - Test for equality of a particular vector element
+ * ------------------------------------------------------------------
+ * INTERNAL USE ONLY.
+@@ -173,11 +236,11 @@
+ *                         1: All equal.
+ *
+ *
+-* wcsutil_Eq() - Test for equality of two double arrays
+-* -----------------------------------------------------
++* wcsutil_dblEq() - Test for equality of two arrays of type double
++* ----------------------------------------------------------------
+ * INTERNAL USE ONLY.
+ *
+-* wcsutil_Eq() tests for equality of two double-precision arrays.
++* wcsutil_dblEq() tests for equality of two double-precision arrays.
+ *
+ * Given:
+ *   nelem     int       The number of elements in each array.
+@@ -199,8 +262,8 @@
+ *                         1: Equal.
+ *
+ *
+-* wcsutil_intEq() - Test for equality of two int arrays
+-* -----------------------------------------------------
++* wcsutil_intEq() - Test for equality of two arrays of type int
++* -------------------------------------------------------------
+ * INTERNAL USE ONLY.
+ *
+ * wcsutil_intEq() tests for equality of two int arrays.
+@@ -245,7 +308,8 @@
+ * --------------------------------------------------
+ * INTERNAL USE ONLY.
+ *
+-* wcsutil_setAll() sets the value of a particular element in a set of vectors.
++* wcsutil_setAll() sets the value of a particular element in a set of vectors
++* of type double.
+ *
+ * Given:
+ *   nvec      int       The number of vectors.
+@@ -273,7 +337,8 @@
+ * --------------------------------------------------
+ * INTERNAL USE ONLY.
+ *
+-* wcsutil_setAli() sets the value of a particular element in a set of vectors.
++* wcsutil_setAli() sets the value of a particular element in a set of vectors
++* of type int.
+ *
+ * Given:
+ *   nvec      int       The number of vectors.
+@@ -406,14 +471,18 @@ extern "C" {
+ 
+ void wcsdealloc(void *ptr);
+ 
+-void wcsutil_strcvt(int n, char c, const char src[], char dst[]);
++void wcsutil_strcvt(int n, char c, int nt, const char src[], char dst[]);
+ 
+ void wcsutil_blank_fill(int n, char c[]);
+ void wcsutil_null_fill (int n, char c[]);
+ 
++int  wcsutil_all_ival(int nelem, int ival, const int iarr[]);
++int  wcsutil_all_dval(int nelem, double dval, const double darr[]);
++int  wcsutil_all_sval(int nelem, const char *sval, const char (*sarr)[72]);
+ int  wcsutil_allEq (int nvec, int nelem, const double *first);
+-int  wcsutil_Eq(int nelem, double tol, const double *arr1,
+-                const double *arr2);
++
++int  wcsutil_dblEq(int nelem, double tol, const double *arr1,
++                   const double *arr2);
+ int  wcsutil_intEq(int nelem, const int *arr1, const int *arr2);
+ int  wcsutil_strEq(int nelem, char (*arr1)[72], char (*arr2)[72]);
+ void wcsutil_setAll(int nvec, int nelem, double *first);
+@@ -428,4 +497,4 @@ int  wcsutil_str2double2(const char *buf
  }
  #endif
  
 -#endif /* WCSLIB_WCSUTIL */
 +#endif // WCSLIB_WCSUTIL
-Index: astropy-4.2/cextern/wcslib/C/wcsutrn.l
+Index: astropy-4.2.1/cextern/wcslib/C/wcsutrn.l
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wcsutrn.l
-+++ astropy-4.2/cextern/wcslib/C/wcsutrn.l
+--- astropy-4.2.1.orig/cextern/wcslib/C/wcsutrn.l
++++ astropy-4.2.1/cextern/wcslib/C/wcsutrn.l
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -33170,25 +39382,51 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutrn.l
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wcsutrn.l,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wcsutrn.l,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wcsutrn.l,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
  * wcsutrn.l is a Flex description file containing the definition of a lexical
-@@ -59,7 +56,7 @@
- static int wcsutrne_scanner(int ctrl, char unitstr[], struct wcserr **err,
-                             yyscan_t yyscanner);
+@@ -43,6 +40,7 @@
+ %option outfile="wcsutrn.c"
+ %option prefix="wcsutrn"
+ %option reentrant
++%option extra-type="struct wcsutrn_extra *"
  
+ /* Exclusive start states. */
+ %x NEXT FLUSH
+@@ -56,64 +54,47 @@
+ #include "wcserr.h"
+ #include "wcsunits.h"
+ 
+-static int wcsutrne_scanner(int ctrl, char unitstr[], struct wcserr **err,
+-                            yyscan_t yyscanner);
+-
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
- 
- int wcsutrne(
-   int ctrl,
-@@ -79,15 +76,15 @@ int wcsutrne(
-   return status;
- }
- 
+-
+-int wcsutrne(
+-  int ctrl,
+-  char unitstr[],
+-  struct wcserr **err)
+-
+-{
+-  int status;
+-  yyscan_t yyscanner;
+-  int yylex_init(yyscan_t *yyscanner);
+-  int yylex_destroy(yyscan_t yyscanner);
+-
+-  yylex_init(&yyscanner);
+-  status = wcsutrne_scanner(ctrl, unitstr, err, yyscanner);
+-  yylex_destroy(yyscanner);
+-
+-  return status;
+-}
+-
 -/*--------------------------------------------------------------------------*/
-+//----------------------------------------------------------------------------
++// User data associated with yyscanner.
++struct wcsutrn_extra {
++  // Used in preempting the call to exit() by yy_fatal_error().
++  jmp_buf abort_jmp_env;
++};
  
  #define YY_DECL int wcsutrne_scanner(int ctrl, char unitstr[], \
   struct wcserr **err, yyscan_t yyscanner)
@@ -33198,20 +39436,50 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutrn.l
  #define YY_INPUT(inbuff, count, bufsize) { count = YY_NULL; }
  
 -/* Used in preempting the call to exit() by yy_fatal_error(). */
-+// Used in preempting the call to exit() by yy_fatal_error().
- jmp_buf wcsutrn_abort_jmp_env;
- #define exit(status) longjmp(wcsutrn_abort_jmp_env, status)
+-jmp_buf wcsutrn_abort_jmp_env;
+-#define exit(status) longjmp(wcsutrn_abort_jmp_env, status)
++// Preempt the call to exit() by yy_fatal_error().
++#define exit(status) longjmp(yyextra->abort_jmp_env, status);
++
++// Internal helper functions.
++static YY_DECL;
  
-@@ -110,7 +107,7 @@ jmp_buf wcsutrn_abort_jmp_env;
+ %}
+ 
+ %%
+-	static const char *function = "wcsutrne";
+-	
+-	char orig[80], subs[80];
+-	int bracket = 0;
+-	int unsafe  = 0;
+-	int status  = -1;
++	static const char *function = "wcsutrne_scanner";
+ 	
+ 	if (err) *err = 0x0;
+ 	
++	char orig[80], subs[80];
+ 	*orig = '\0';
+ 	*subs = '\0';
+ 	
++	int bracket = 0;
++	int unsafe  = 0;
++	int status  = -1;
++	
+ 	yy_delete_buffer(YY_CURRENT_BUFFER, yyscanner);
  	yy_scan_string(unitstr, yyscanner);
  	*unitstr = '\0';
  	
 -	/* Return here via longjmp() invoked by yy_fatal_error(). */
+-	if (setjmp(wcsutrn_abort_jmp_env)) {
 +	// Return here via longjmp() invoked by yy_fatal_error().
- 	if (setjmp(wcsutrn_abort_jmp_env)) {
++	if (setjmp(yyextra->abort_jmp_env)) {
  	  return wcserr_set(WCSERR_SET(UNITSERR_PARSER_ERROR),
- 	    "Internal units translator error parsing '%s'", unitstr);
-@@ -123,22 +120,22 @@ jmp_buf wcsutrn_abort_jmp_env;
+-	    "Internal units translator error parsing '%s'", unitstr);
++	    "Internal units translator error");
+ 	}
+ 	
+ 	BEGIN(INITIAL);
+@@ -123,22 +104,22 @@ jmp_buf wcsutrn_abort_jmp_env;
  	#endif
  
  ^" "*"[" {
@@ -33238,7 +39506,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutrn.l
  	  strcpy(orig, yytext);
  	  strcpy(subs, "Angstrom");
  	  BEGIN(NEXT);
-@@ -304,25 +301,25 @@ years?|YR|YEARS? {
+@@ -304,25 +285,25 @@ years?|YR|YEARS? {
  	}
  
  [A-Za-z]+ {
@@ -33268,7 +39536,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutrn.l
  	  strcat(unitstr, subs);
  	  strcat(unitstr, " ");
  	  if (strcmp(orig, subs)) status = 0;
-@@ -332,7 +329,7 @@ years?|YR|YEARS? {
+@@ -332,7 +313,7 @@ years?|YR|YEARS? {
  	}
  
  <NEXT>.	{
@@ -33277,7 +39545,7 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutrn.l
  	  strcat(unitstr, subs);
  	  if (strcmp(orig, subs)) status = 0;
  	  unput(*yytext);
-@@ -341,12 +338,12 @@ years?|YR|YEARS? {
+@@ -341,12 +322,12 @@ years?|YR|YEARS? {
  	}
  
  <FLUSH>.* {
@@ -33292,16 +39560,45 @@ Index: astropy-4.2/cextern/wcslib/C/wcsutrn.l
  	  if (*subs) {
  	    strcat(unitstr, subs);
  	    if (strcmp(orig, subs)) status = 0;
-Index: astropy-4.2/cextern/wcslib/C/wtbarr.h
+@@ -360,3 +341,28 @@ years?|YR|YEARS? {
+ 	}
+ 
+ %%
++
++/*----------------------------------------------------------------------------
++* External interface to the scanner.
++*---------------------------------------------------------------------------*/
++
++int wcsutrne(
++  int ctrl,
++  char unitstr[],
++  struct wcserr **err)
++
++{
++  static const char *function = "wcsutrne";
++
++  // Function prototypes.
++  int yylex_init_extra(YY_EXTRA_TYPE extra, yyscan_t *yyscanner);
++  int yylex_destroy(yyscan_t yyscanner);
++
++  struct wcsutrn_extra extra;
++  yyscan_t yyscanner;
++  yylex_init_extra(&extra, &yyscanner);
++  int status = wcsutrne_scanner(ctrl, unitstr, err, yyscanner);
++  yylex_destroy(yyscanner);
++
++  return status;
++}
+Index: astropy-4.2.1/cextern/wcslib/C/wtbarr.h
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/C/wtbarr.h
-+++ astropy-4.2/cextern/wcslib/C/wtbarr.h
+--- astropy-4.2.1.orig/cextern/wcslib/C/wtbarr.h
++++ astropy-4.2.1/cextern/wcslib/C/wtbarr.h
 @@ -1,7 +1,6 @@
  /*============================================================================
 -
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -33315,11 +39612,11 @@ Index: astropy-4.2/cextern/wcslib/C/wtbarr.h
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: wtbarr.h,v 7.3 2020/06/03 03:37:02 mcalabre Exp $
-+  $Id: wtbarr.h,v 7.4 2021/01/31 02:24:51 mcalabre Exp $
++  $Id: wtbarr.h,v 7.6 2021/04/13 12:57:01 mcalabre Exp $
  *=============================================================================
  *
 -* WCSLIB 7.3 - C routines that implement the FITS World Coordinate System
-+* WCSLIB 7.4 - C routines that implement the FITS World Coordinate System
++* WCSLIB 7.6 - C routines that implement the FITS World Coordinate System
  * (WCS) standard.  Refer to the README file provided with WCSLIB for an
  * overview of the library.
  *
@@ -33370,11 +39667,131 @@ Index: astropy-4.2/cextern/wcslib/C/wtbarr.h
  
 -#endif /* WCSLIB_WTBARR */
 +#endif // WCSLIB_WTBARR
-Index: astropy-4.2/cextern/wcslib/CHANGES
+Index: astropy-4.2.1/cextern/wcslib/CHANGES
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/CHANGES
-+++ astropy-4.2/cextern/wcslib/CHANGES
-@@ -1,3 +1,66 @@
+--- astropy-4.2.1.orig/cextern/wcslib/CHANGES
++++ astropy-4.2.1/cextern/wcslib/CHANGES
+@@ -1,3 +1,186 @@
++WCSLIB version 7.6 (2021/04/13)
++-------------------------------
++
++* C library
++
++  - Bug fix in tabs2x() triggered for 1-dimensional coordinate lookup
++    tables on axes > 1.  Reported by Mihai Cara.
++
++  - In datfix(), don't return status 0 if no change was made (fix for
++    change made at release 7.4).  Reported by Derek Homeier.
++
++  - New function wcspcx() in the wcsfix suite regularizes the linear
++    transformation component of a coordinate description to make it more
++    human-readable.  It decomposes CDi_ja into PCi_ja and CDELTia in
++    such a way that CDELTia forms meaningful scaling parameters, often
++    leaving an orthogonal or near-orthogonal matrix.  Optionally, it can
++    then permute rows of this matrix to unscramble axis permutations.
++
++    A test header may be generated from wcspcx.keyrec for input to
++    wcsware (not exercised as part of the standard test suite).
++
++  - New function wcstrim() frees memory allocated by wcsinit() for
++    arrays in a wcsprm struct that remain unused after the struct has
++    been set up.
++
++  - New functions wcssize(), auxsize(), tabsize(), linsize(), dissize(),
++    celsize(), prjsize(), spcsize(), and wcserr_size() compute the total
++    size of the relevant structs, including allocated memory.
++
++  - In the C test suite, inserted a brief pause in tprj2 and tspc, which
++    otherwise have now become a blur.
++
++* Fortran wrappers
++
++  - Added wrappers for wcspcx(), wcstrim(), wcssize(), auxsize(),
++    tabsize(), linsize(), dissize(), celsize(), prjsize(), spcsize(),
++    and wcserr_size().
++
++* Utilities
++
++  - Added -c, -cp, -C, and -Cp options to wcsware to apply wcspcx()
++    in a variety of ways, -m to apply wcstrim(), and -z to report the
++    total size of the wcsprm struct with a breakdown of the sizes of
++    its constituent structs.
++
++  - Fixed compiler warnings for sundazel (portability issue).
++
++* Installation
++
++  - Upped the required version of Flex to 2.6.0 (was 2.5.9).  Problems
++    with Flex 2.5.39 reported by Derek Homeier.
++
++    Also added '--disable-flex' as a new configure option to force the
++    use of the pre-generated Flex sources.
++
++
++WCSLIB version 7.5 (2021/03/20)
++-------------------------------
++
++The C code in WCSLIB is moving piecemeal to the C99 standard.  In fact,
++various indispensible C99 constructs have been used in WCSLIB for many
++years: the long long int data type (in fitshdr() only); stdint.h,
++inttypes.h, and the use of PRI formatting control (in wcsprintf(), which
++is widely used by the library); and the C99-extended library function
++vsnprintf() (used by wcserr for a decade).  Flex-generated C code also
++uses C99 extensions, though with workarounds if they are not available.
++
++Except in the header prologues, which are formatted in a special way for
++generating the user manual, comments were changed en masse to C99 style
++in release 7.3.1, and variable declarations in code that I have occasion
++to modify will transition to the more general placement allowed by C99.
++However, I have no plans to use any of the more esoteric features of
++C99.
++
++* C library
++
++  - New function, wcsccs(), changes the celestial coordinate system of a
++    wcsprm struct, for example, from equatorial to galactic coordinates.
++    The parameters that define the spherical coordinate transformation
++    must be provided.  This allows WCSLIB to provide this functionality
++    without needing to know anything about specific celestial coordinate
++    systems, and has the advantage of making the routine completely
++    general.  Requested by Mohammad Akhlaghi.
++
++    Modified test program twcsfix also to test wcsccs().
++
++  - Fixed a problem common to all of the Flex code (fitshdr, wcsbth,
++    wcspih, wcsulex, and wcsutrn) that made it thread-unsafe.  Reported
++    by Cyril Richard.
++
++    Added a new test program, tpthreads, to test thread safety.  It is
++    only used for code development, and not exercised as part of the
++    standard test suite.
++
++  - In fitshdr(), fixed a problem that potentially could arise on
++    systems where sizeof(long long int) is greater than 8 (64 bits).
++
++* Fortran wrappers
++
++  - Match changes to the C library: added a wrapper for wcsccs(), and
++    modified twcsfix.f.
++
++  - Because null addresses cannot be passed to functions in Fortran,
++    wcssub_() now interprets *nsub == -1 && *axes == -1 as a signal to
++    do a deep copy of one wcsprm struct to another.
++
++* Utilities
++
++  - New utility, sundazel, computes the local time of the Sun's passage
++    through the specified apparent longitude or latitude in a user-
++    defined coordinate system.  It can also perform several other Solar
++    related calculations.  (It is unrelated to FITS WCS, and does not
++    use WCSLIB.)
++
++* Installation
++
++  - Added an 'uninstall' rule to the makefiles.  Suggested by
++    Cyril Richard.
++
++
 +WCSLIB version 7.4 (2021/01/31)
 +-------------------------------
 +
@@ -33441,40 +39858,91 @@ Index: astropy-4.2/cextern/wcslib/CHANGES
  WCSLIB version 7.3 (2020/06/03)
  -------------------------------
  
-@@ -3030,4 +3093,4 @@ WCSLIB version 1.0 (1995/01/31)
+@@ -3030,4 +3213,4 @@ WCSLIB version 1.0 (1995/01/31)
    Initial release.
  
  ------------------------------------------------------------------------
 -$Id: CHANGES,v 7.3 2020/06/03 03:37:03 mcalabre Exp $
-+$Id: CHANGES,v 7.4 2021/01/31 02:24:52 mcalabre Exp $
-Index: astropy-4.2/cextern/wcslib/GNUmakefile
++$Id: CHANGES,v 7.6 2021/04/13 12:57:02 mcalabre Exp $
+Index: astropy-4.2.1/cextern/wcslib/GNUmakefile
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/GNUmakefile
-+++ astropy-4.2/cextern/wcslib/GNUmakefile
+--- astropy-4.2.1.orig/cextern/wcslib/GNUmakefile
++++ astropy-4.2.1/cextern/wcslib/GNUmakefile
 @@ -1,5 +1,5 @@
  #-----------------------------------------------------------------------------
 -# GNU makefile for building WCSLIB 7.3
-+# GNU makefile for building WCSLIB 7.4
++# GNU makefile for building WCSLIB 7.6
  #
  # Summary of the main targets
  # ---------------------------
-@@ -32,7 +32,7 @@
+@@ -8,6 +8,8 @@
+ #   tests:     Do 'make tests' in each subdirectory (compile test programs but
+ #              don't run them).
+ #   install:   Do 'make install' in each subdirectory.
++#   uninstall: Deletes installed files (this release only), including the
++#              sharable library.
+ #   clean:     Recursively delete intermediate files produced as part of the
+ #              build, e.g. object modules, core dumps, etc.
+ #   cleaner:   Recursively clean, and also delete test executables, test
+@@ -32,7 +34,7 @@
  #
  # Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
  # http://www.atnf.csiro.au/people/Mark.Calabretta
 -# $Id: GNUmakefile,v 7.3 2020/06/03 03:37:03 mcalabre Exp $
-+# $Id: GNUmakefile,v 7.4 2021/01/31 02:24:52 mcalabre Exp $
++# $Id: GNUmakefile,v 7.6 2021/04/13 12:57:02 mcalabre Exp $
  #-----------------------------------------------------------------------------
  # Get configure settings.
  SUBDIR := .
-Index: astropy-4.2/cextern/wcslib/INSTALL
+@@ -43,7 +45,7 @@ ifeq "$(CHECK)" "nopgplot"
+ endif
+ 
+ .PHONY : build check chmod clean cleaner cleanest distclean install \
+-         realclean show tests writable
++         realclean show tests uninstall writable
+ 
+ build :
+ 	-@ for DIR in $(SUBDIRS) ; do \
+@@ -81,6 +83,10 @@ install :
+ 	 @ for DIR in $(INSTDIR) ; do \
+ 	     $(MAKE) -k -C $$DIR $@ ; \
+ 	   done
++	   if [ ! -d "$(LIBDIR)/pkgconfig" ] ; then \
++	     $(INSTALL) -d -m 775 $(LIBDIR)/pkgconfig ; \
++	   fi
++	   $(INSTALL) -m 444 wcslib.pc $(LIBDIR)/pkgconfig/wcslib.pc
+ 	   $(INSTALL) -m 444 wcsconfig.h wcsconfig_f77.h $(INCDIR)
+ 	-  if [ ! -d "$(DOCDIR)" ] ; then \
+ 	     $(INSTALL) -d -m 775 $(DOCDIR) ; \
+@@ -98,10 +104,17 @@ install :
+ 	     $(INSTALL) -d -m 775 $(HTMLDIR)/html ; \
+ 	   fi
+ 	   $(INSTALL) -m 444 html/* $(HTMLDIR)/html
+-	   if [ ! -d "$(LIBDIR)/pkgconfig" ] ; then \
+-	     $(INSTALL) -d -m 775 $(LIBDIR)/pkgconfig ; \
+-	   fi
+-	   $(INSTALL) -m 444 wcslib.pc $(LIBDIR)/pkgconfig/wcslib.pc
++
++uninstall :
++	 @ for DIR in $(INSTDIR) ; do \
++	     $(MAKE) -k -C $$DIR $@ ; \
++	   done
++	-  cd $(LIBDIR) && $(RM) pkgconfig/wcslib.pc
++	-  cd $(INCDIR) && $(RM) wcsconfig*.h
++	-  $(RM) $(DOCLINK)
++	-  $(RM) $(DOCDIR)
++	-  $(RM) $(PDFDIR)
++	-  $(RM) $(HTMLDIR)
+ 
+ clean cleaner :
+ 	   for DIR in $(SUBDIRS) doxygen ; do \
+Index: astropy-4.2.1/cextern/wcslib/INSTALL
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/INSTALL
-+++ astropy-4.2/cextern/wcslib/INSTALL
+--- astropy-4.2.1.orig/cextern/wcslib/INSTALL
++++ astropy-4.2.1/cextern/wcslib/INSTALL
 @@ -1,5 +1,5 @@
  ------------------------------------------------------------------------------
 -WCSLIB 7.3 and PGSBOX 7.3 INSTALLATION
-+WCSLIB 7.4 and PGSBOX 7.4 INSTALLATION
++WCSLIB 7.6 and PGSBOX 7.6 INSTALLATION
  --------------------------------------
  
  WCSLIB requires an ANSI C compiler with standard ANSI C environment, that is,
@@ -33484,8 +39952,8 @@ Index: astropy-4.2/cextern/wcslib/INSTALL
  
 -  tar pxvf wcslib-7.3.tar.bz2
 -  cd wcslib-7.3
-+  tar pxvf wcslib-7.4.tar.bz2
-+  cd wcslib-7.4
++  tar pxvf wcslib-7.6.tar.bz2
++  cd wcslib-7.6
    make install
  
  Otherwise, read on.
@@ -33495,8 +39963,8 @@ Index: astropy-4.2/cextern/wcslib/INSTALL
  
 -  bzcat wcslib-7.3.tar.bz2 | tar pvxf -
 -  cd wcslib-7.3
-+  bzcat wcslib-7.4.tar.bz2 | tar pvxf -
-+  cd wcslib-7.4
++  bzcat wcslib-7.6.tar.bz2 | tar pvxf -
++  cd wcslib-7.6
  
  then if you do not need to specify any configuration options, simply run
  
@@ -33505,22 +39973,22 @@ Index: astropy-4.2/cextern/wcslib/INSTALL
  Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
  http://www.atnf.csiro.au/people/Mark.Calabretta
 -$Id: INSTALL,v 7.3 2020/06/03 03:37:03 mcalabre Exp $
-+$Id: INSTALL,v 7.4 2021/01/31 02:24:52 mcalabre Exp $
++$Id: INSTALL,v 7.6 2021/04/13 12:57:02 mcalabre Exp $
  
  ==============================================================================
  
-Index: astropy-4.2/cextern/wcslib/README
+Index: astropy-4.2.1/cextern/wcslib/README
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/README
-+++ astropy-4.2/cextern/wcslib/README
+--- astropy-4.2.1.orig/cextern/wcslib/README
++++ astropy-4.2.1/cextern/wcslib/README
 @@ -1,8 +1,8 @@
  ------------------------------------------------------------------------------
 -                         WCSLIB 7.3 and PGSBOX 7.3
-+                         WCSLIB 7.4 and PGSBOX 7.4
++                         WCSLIB 7.6 and PGSBOX 7.6
  ------------------------------------------------------------------------------
 -  WCSLIB 7.3 - an implementation of the FITS WCS standard.
 -  Copyright (C) 1995-2020, Mark Calabretta
-+  WCSLIB 7.4 - an implementation of the FITS WCS standard.
++  WCSLIB 7.6 - an implementation of the FITS WCS standard.
 +  Copyright (C) 1995-2021, Mark Calabretta
  
    This file is part of WCSLIB.
@@ -33534,14 +40002,14 @@ Index: astropy-4.2/cextern/wcslib/README
    Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
    http://www.atnf.csiro.au/people/Mark.Calabretta
 -  $Id: README,v 7.3 2020/06/03 03:37:03 mcalabre Exp $
-+  $Id: README,v 7.4 2021/01/31 02:24:52 mcalabre Exp $
++  $Id: README,v 7.6 2021/04/13 12:57:02 mcalabre Exp $
  ------------------------------------------------------------------------------
  
  Please refer to
-Index: astropy-4.2/cextern/wcslib/THANKS
+Index: astropy-4.2.1/cextern/wcslib/THANKS
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/THANKS
-+++ astropy-4.2/cextern/wcslib/THANKS
+--- astropy-4.2.1.orig/cextern/wcslib/THANKS
++++ astropy-4.2.1/cextern/wcslib/THANKS
 @@ -2,7 +2,7 @@ I would like to acknowledge the followin
  to WCSLIB and/or PGSBOX in some way since 1995 - via bug reports,
  patches, suggestions for improvements, positive feedback, etc.
@@ -33585,7 +40053,14 @@ Index: astropy-4.2/cextern/wcslib/THANKS
  Michelle Miller (NOAO)
  Jessica Mink (CfA)
  David Motl (var.astro.cz)
-@@ -86,7 +88,7 @@ Keith A. Scollick (GSFC/NASA)
+@@ -80,13 +82,14 @@ Ray Plante (NCSA/UIUC)
+ Paul Price (Princeton U.)
+ Niruj Mohan Ramanujam (Leiden Obs)
+ Harold Ravlin (U. Illinois)
++Cyril Richard (CNRS)
+ Thomas Robitaille (MPIA, STScI)
+ Boud Roukema (TCfA)
+ Keith A. Scollick (GSFC/NASA)
  Arno Schoenmakers (ASTRON)
  Pim Schellart (Princeton U.)
  Corentin Schreiber (Oxford U.)
@@ -33594,19 +40069,39 @@ Index: astropy-4.2/cextern/wcslib/THANKS
  Colin Slater (LSST)
  Hanno Spreeuw (ASTRON)
  Ole Streicher (Debian maintainer)
-@@ -108,4 +110,4 @@ Daren Scot Wilson (NRAO)
+@@ -108,4 +111,4 @@ Daren Scot Wilson (NRAO)
  Tony Wong (ATNF/CSIRO)
  
  
 -$Id: THANKS,v 7.3 2020/06/03 03:37:03 mcalabre Exp $
-+$Id: THANKS,v 7.3.1.4 2021/01/31 01:24:38 mcalabre Exp $
-Index: astropy-4.2/cextern/wcslib/VALIDATION
++$Id: THANKS,v 7.6 2021/04/13 12:57:02 mcalabre Exp $
+Index: astropy-4.2.1/cextern/wcslib/VALIDATION
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/VALIDATION
-+++ astropy-4.2/cextern/wcslib/VALIDATION
-@@ -1,5 +1,25 @@
+--- astropy-4.2.1.orig/cextern/wcslib/VALIDATION
++++ astropy-4.2.1/cextern/wcslib/VALIDATION
+@@ -1,5 +1,45 @@
  Platforms on which the installation procedures and test suite were exercised.
  
++WCSLIB version 7.6 (2021/04/13)
++-------------------------------
++
++* Dell Latitude E6530 (Intel Core i7-3740QM, 4 cores, 8 processors, x86_64)
++  KDE Neon User Edition 5.21 (over Kubuntu 20.04, (focal))
++  uname -r (kernel version): 5.4.0-67-generic
++  gcc --version: gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0
++  gfortran --version: GNU Fortran (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0
++
++
++WCSLIB version 7.5 (2021/03/20)
++-------------------------------
++
++* Dell Latitude XPS 15 9560 (Intel Core i7-7700HQ, 4 cores, 8 CPUs, x86_64)
++  KDE Neon User Edition 5.20 (over Kubuntu 20.04, (focal))
++  uname -r (kernel version): 5.4.0-62-generic
++  gcc --version: gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0
++  gfortran --version: GNU Fortran (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0
++
++
 +WCSLIB version 7.4 (2021/01/31)
 +-------------------------------
 +
@@ -33630,23 +40125,23 @@ Index: astropy-4.2/cextern/wcslib/VALIDATION
  WCSLIB version 7.3 (2020/06/03)
  -------------------------------
  
-@@ -626,4 +646,4 @@ WCSLIB version 4.4 (2009/08/06)
+@@ -626,4 +666,4 @@ WCSLIB version 4.4 (2009/08/06)
            2004/04/23
  
  ------------------------------------------------------------------------------
 -$Id: VALIDATION,v 7.3 2020/06/03 03:37:03 mcalabre Exp $
-+$Id: VALIDATION,v 7.4 2021/01/31 02:24:52 mcalabre Exp $
-Index: astropy-4.2/cextern/wcslib/configure
++$Id: VALIDATION,v 7.6 2021/04/13 12:57:02 mcalabre Exp $
+Index: astropy-4.2.1/cextern/wcslib/configure
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/configure
-+++ astropy-4.2/cextern/wcslib/configure
+--- astropy-4.2.1.orig/cextern/wcslib/configure
++++ astropy-4.2.1/cextern/wcslib/configure
 @@ -1,7 +1,7 @@
  #! /bin/sh
 -# From configure.ac Revision: 7.3 .
-+# From configure.ac Revision: 7.4 .
++# From configure.ac Revision: 7.6 .
  # Guess values for system-dependent variables and create Makefiles.
 -# Generated by GNU Autoconf 2.69 for WCSLIB 7.3.
-+# Generated by GNU Autoconf 2.69 for WCSLIB 7.4.
++# Generated by GNU Autoconf 2.69 for WCSLIB 7.6.
  #
  # Report bugs to <mark@calabretta.id.au>.
  #
@@ -33657,116 +40152,397 @@ Index: astropy-4.2/cextern/wcslib/configure
 -PACKAGE_TARNAME='wcslib-7.3'
 -PACKAGE_VERSION='7.3'
 -PACKAGE_STRING='WCSLIB 7.3'
-+PACKAGE_TARNAME='wcslib-7.4'
-+PACKAGE_VERSION='7.4'
-+PACKAGE_STRING='WCSLIB 7.4'
++PACKAGE_TARNAME='wcslib-7.6'
++PACKAGE_VERSION='7.6'
++PACKAGE_STRING='WCSLIB 7.6'
  PACKAGE_BUGREPORT='mark@calabretta.id.au'
  PACKAGE_URL=''
  
-@@ -1290,7 +1290,7 @@ if test "$ac_init_help" = "long"; then
+@@ -625,6 +625,9 @@ ac_includes_default="\
+ 
+ ac_subst_vars='LTLIBOBJS
+ FLAVOUR
++OBSTZ
++OBSLAT
++OBSLNG
+ INSTDIR
+ TSTDIRS
+ SUBDIRS
+@@ -716,6 +719,7 @@ SHELL'
+ ac_subst_files=''
+ ac_user_opts='
+ enable_option_checking
++enable_flex
+ enable_fortran
+ enable_shared
+ enable_largefile
+@@ -1290,7 +1294,7 @@ if test "$ac_init_help" = "long"; then
    # Omit some internal or obsolete options to make the list less imposing.
    # This message is too long to be a string in the A/UX 3.1 sh.
    cat <<_ACEOF
 -\`configure' configures WCSLIB 7.3 to adapt to many kinds of systems.
-+\`configure' configures WCSLIB 7.4 to adapt to many kinds of systems.
++\`configure' configures WCSLIB 7.6 to adapt to many kinds of systems.
  
  Usage: $0 [OPTION]... [VAR=VALUE]...
  
-@@ -1339,7 +1339,7 @@ Fine tuning of the installation director
+@@ -1339,7 +1343,7 @@ Fine tuning of the installation director
    --infodir=DIR           info documentation [DATAROOTDIR/info]
    --localedir=DIR         locale-dependent data [DATAROOTDIR/locale]
    --mandir=DIR            man documentation [DATAROOTDIR/man]
 -  --docdir=DIR            documentation root [DATAROOTDIR/doc/wcslib-7.3]
-+  --docdir=DIR            documentation root [DATAROOTDIR/doc/wcslib-7.4]
++  --docdir=DIR            documentation root [DATAROOTDIR/doc/wcslib-7.6]
    --htmldir=DIR           html documentation [DOCDIR]
    --dvidir=DIR            dvi documentation [DOCDIR]
    --pdfdir=DIR            pdf documentation [DOCDIR]
-@@ -1360,7 +1360,7 @@ fi
+@@ -1360,7 +1364,7 @@ fi
  
  if test -n "$ac_init_help"; then
    case $ac_init_help in
 -     short | recursive ) echo "Configuration of WCSLIB 7.3:";;
-+     short | recursive ) echo "Configuration of WCSLIB 7.4:";;
++     short | recursive ) echo "Configuration of WCSLIB 7.6:";;
     esac
    cat <<\_ACEOF
  
-@@ -1464,7 +1464,7 @@ fi
+@@ -1368,6 +1372,7 @@ Optional Features:
+   --disable-option-checking  ignore unrecognized --enable/--with options
+   --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
+   --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
++  --disable-flex          don't apply flex (use pre-generated sources)
+   --enable-fortran=ARG    Fortran compiler to use
+   --disable-fortran       don't build the Fortran wrappers or PGSBOX
+   --disable-shared        don't build the WCS shared libraries
+@@ -1464,7 +1469,7 @@ fi
  test -n "$ac_init_help" && exit $ac_status
  if $ac_init_version; then
    cat <<\_ACEOF
 -WCSLIB configure 7.3
-+WCSLIB configure 7.4
++WCSLIB configure 7.6
  generated by GNU Autoconf 2.69
  
  Copyright (C) 2012 Free Software Foundation, Inc.
-@@ -2238,7 +2238,7 @@ cat >config.log <<_ACEOF
+@@ -2238,7 +2243,7 @@ cat >config.log <<_ACEOF
  This file contains any messages produced by compilers while
  running configure, to aid debugging if configure makes a mistake.
  
 -It was created by WCSLIB $as_me 7.3, which was
-+It was created by WCSLIB $as_me 7.4, which was
++It was created by WCSLIB $as_me 7.6, which was
  generated by GNU Autoconf 2.69.  Invocation command line was
  
    $ $0 $@
-@@ -9061,7 +9061,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_wri
+@@ -2707,7 +2712,20 @@ ARCH="${host_cpu}-$host_os"
+ 
+ 
+ # Look for Flex.
+-# Extract the first word of "flex", so it can be a program name with args.
++# Check whether --enable-flex was given.
++if test "${enable_flex+set}" = set; then :
++  enableval=$enable_flex;
++fi
++
++if test "x$enable_flex" = xno ; then
++  FLEX=
++  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Generation of flex sources disabled by request, using
++           pre-generated sources." >&5
++$as_echo "$as_me: WARNING: Generation of flex sources disabled by request, using
++           pre-generated sources." >&2;}
++
++else
++  # Extract the first word of "flex", so it can be a program name with args.
+ set dummy flex; ac_word=$2
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+ $as_echo_n "checking for $ac_word... " >&6; }
+@@ -2744,25 +2762,26 @@ $as_echo "no" >&6; }
+ fi
+ 
+ 
+-if test "x$FLEX" = xflex ; then
+-  # Version 2.5.9 or later is required.
+-  V=`flex --version | awk '{print $2}'`
+-  W=`echo $V | awk -F. '{if ((($1*100 + $2)*100 + $3) < 20509) print "no"}'`
+-  if test "x$W" != x ; then
+-    { $as_echo "$as_me:${as_lineno-$LINENO}: Flex version $V is too old, ignored." >&5
+-$as_echo "$as_me: Flex version $V is too old, ignored." >&6;}
+-    FLEX=
+-  else
+-    { $as_echo "$as_me:${as_lineno-$LINENO}: Using Flex version $V." >&5
++  if test "x$FLEX" = xflex ; then
++    # Version 2.6.0 or later is required.
++    V=`flex --version | awk '{print $2}'`
++    W=`echo $V | awk -F. '{if ((($1*100 + $2)*100 + $3) < 20600) print "no"}'`
++    if test "x$W" != x ; then
++      { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Flex version $V is too old, ignored." >&5
++$as_echo "$as_me: WARNING: Flex version $V is too old, ignored." >&2;}
++      FLEX=
++    else
++      { $as_echo "$as_me:${as_lineno-$LINENO}: Using Flex version $V." >&5
+ $as_echo "$as_me: Using Flex version $V." >&6;}
++    fi
+   fi
+-fi
+ 
+-if test "x$FLEX" = x ; then
+-  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Flex version 2.5.9 or later does not appear to be
++  if test "x$FLEX" = x ; then
++    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Flex version 2.6.0 or later does not appear to be
+            available, will use pre-generated sources." >&5
+-$as_echo "$as_me: WARNING: Flex version 2.5.9 or later does not appear to be
++$as_echo "$as_me: WARNING: Flex version 2.6.0 or later does not appear to be
+            available, will use pre-generated sources." >&2;}
++  fi
+ fi
+ 
+ 
+@@ -5771,8 +5790,8 @@ fi
+ if test "x$F77" = xno ; then
+   F77=
+ 
+-  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Compilation of Fortran wrappers and PGSBOX disabled" >&5
+-$as_echo "$as_me: WARNING: Compilation of Fortran wrappers and PGSBOX disabled" >&2;}
++  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Compilation of Fortran wrappers and PGSBOX disabled." >&5
++$as_echo "$as_me: WARNING: Compilation of Fortran wrappers and PGSBOX disabled." >&2;}
+ 
+ else
+   if test "x$F77" = x ; then
+@@ -6937,8 +6956,8 @@ SHRLN=
+ 
+ if test "x$ac_cv_c_compiler_gnu" = xyes ; then
+   if test "x$enable_shared" = xno ; then
+-    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Generation of WCS shared libraries disabled" >&5
+-$as_echo "$as_me: WARNING: Generation of WCS shared libraries disabled" >&2;}
++    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Generation of WCS shared libraries disabled." >&5
++$as_echo "$as_me: WARNING: Generation of WCS shared libraries disabled." >&2;}
+ 
+   else
+     SHVER=`echo "$LIBVER" | sed -e 's/\..*$//'`
+@@ -7453,8 +7472,8 @@ if test "${with_cfitsio+set}" = set; the
+ fi
+ 
+ if test "x$with_cfitsio" = xno ; then
+-  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: CFITSIO disabled" >&5
+-$as_echo "$as_me: WARNING: CFITSIO disabled" >&2;}
++  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: CFITSIO disabled." >&5
++$as_echo "$as_me: WARNING: CFITSIO disabled." >&2;}
+ else
+ 
+ # Check whether --with-cfitsiolib was given.
+@@ -7492,8 +7511,8 @@ if test "${with_pgplot+set}" = set; then
+ fi
+ 
+ if test "x$with_pgplot" = xno ; then
+-  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: PGPLOT disabled" >&5
+-$as_echo "$as_me: WARNING: PGPLOT disabled" >&2;}
++  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: PGPLOT disabled." >&5
++$as_echo "$as_me: WARNING: PGPLOT disabled." >&2;}
+ else
+ 
+ # Check whether --with-pgplotlib was given.
+@@ -8521,13 +8540,28 @@ if test "${enable_utils+set}" = set; the
+ fi
+ 
+ if test "x$enable_utils" = xno ; then
+-  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Compilation of WCS utilities disabled" >&5
+-$as_echo "$as_me: WARNING: Compilation of WCS utilities disabled" >&2;}
++  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: Compilation of WCS utilities disabled." >&5
++$as_echo "$as_me: WARNING: Compilation of WCS utilities disabled." >&2;}
+ else
+   SUBDIRS="$SUBDIRS utils"
+   INSTDIR="$INSTDIR utils"
+ fi
+ 
++# Default observer coordinates for sundazel.
++if test -f "$HOME/.sundazelrc"; then
++  . "$HOME/.sundazelrc"
++fi
++
++if test "x$OBSLNG" = x; then
++  OBSLNG=0.0
++  OBSLAT=0.0
++  OBSTZ=0.0
++fi
++
++
++
++
++
+ 
+ 
+ 
+@@ -9061,7 +9095,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_wri
  # report actual input values of CONFIG_FILES etc. instead of their
  # values after options handling.
  ac_log="
 -This file was extended by WCSLIB $as_me 7.3, which was
-+This file was extended by WCSLIB $as_me 7.4, which was
++This file was extended by WCSLIB $as_me 7.6, which was
  generated by GNU Autoconf 2.69.  Invocation command line was
  
    CONFIG_FILES    = $CONFIG_FILES
-@@ -9123,7 +9123,7 @@ _ACEOF
+@@ -9123,7 +9157,7 @@ _ACEOF
  cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
  ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
  ac_cs_version="\\
 -WCSLIB config.status 7.3
-+WCSLIB config.status 7.4
++WCSLIB config.status 7.6
  configured by $0, generated by GNU Autoconf 2.69,
    with options \\"\$ac_cs_config\\"
  
-Index: astropy-4.2/cextern/wcslib/configure.ac
+Index: astropy-4.2.1/cextern/wcslib/configure.ac
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/configure.ac
-+++ astropy-4.2/cextern/wcslib/configure.ac
+--- astropy-4.2.1.orig/cextern/wcslib/configure.ac
++++ astropy-4.2.1/cextern/wcslib/configure.ac
 @@ -3,12 +3,12 @@
  #-----------------------------------------------------------------------------
  # Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
  # http://www.atnf.csiro.au/people/Mark.Calabretta
 -# $Id: configure.ac,v 7.3 2020/06/03 03:37:03 mcalabre Exp $
-+# $Id: configure.ac,v 7.4 2021/01/31 02:24:52 mcalabre Exp $
++# $Id: configure.ac,v 7.6 2021/04/13 12:57:02 mcalabre Exp $
  #-----------------------------------------------------------------------------
  
 -AC_INIT([WCSLIB], [7.3], [mark@calabretta.id.au], [wcslib-7.3])
-+AC_INIT([WCSLIB], [7.4], [mark@calabretta.id.au], [wcslib-7.4])
++AC_INIT([WCSLIB], [7.6], [mark@calabretta.id.au], [wcslib-7.6])
  AC_PREREQ([2.53])
 -AC_REVISION([$Revision: 7.3 $])
-+AC_REVISION([$Revision: 7.4 $])
++AC_REVISION([$Revision: 7.6 $])
  AC_SUBST([PACKAGE_VERSION])
  AC_DEFINE_UNQUOTED([WCSLIB_VERSION], [$PACKAGE_VERSION], [Define wcslib version])
  
-Index: astropy-4.2/cextern/wcslib/flavours
+@@ -26,22 +26,31 @@ AC_SUBST([ARCH])
+ 
+ 
+ # Look for Flex.
+-AC_CHECK_PROG([FLEX], [flex], [flex], [], [], [])
+-if test "x$FLEX" = xflex ; then
+-  # Version 2.5.9 or later is required.
+-  V=`flex --version | awk '{print $2}'`
+-  W=`echo $V | awk -F. '{if ((($1*100 + $2)*100 + $3) < 20509) print "no"}'`
+-  if test "x$W" != x ; then
+-    AC_MSG_NOTICE([Flex version $V is too old, ignored.])
+-    FLEX=
+-  else
+-    AC_MSG_NOTICE([Using Flex version $V.])
++AC_ARG_ENABLE([flex], [AS_HELP_STRING([--disable-flex],
++            [don't apply flex (use pre-generated sources)])], [])
++if test "x$enable_flex" = xno ; then
++  FLEX=
++  AC_MSG_WARN([Generation of flex sources disabled by request, using
++           pre-generated sources.])
++
++else
++  AC_CHECK_PROG([FLEX], [flex], [flex], [], [], [])
++  if test "x$FLEX" = xflex ; then
++    # Version 2.6.0 or later is required.
++    V=`flex --version | awk '{print $2}'`
++    W=`echo $V | awk -F. '{if ((($1*100 + $2)*100 + $3) < 20600) print "no"}'`
++    if test "x$W" != x ; then
++      AC_MSG_WARN([Flex version $V is too old, ignored.])
++      FLEX=
++    else
++      AC_MSG_NOTICE([Using Flex version $V.])
++    fi
+   fi
+-fi
+ 
+-if test "x$FLEX" = x ; then
+-  AC_MSG_WARN([Flex version 2.5.9 or later does not appear to be
++  if test "x$FLEX" = x ; then
++    AC_MSG_WARN([Flex version 2.6.0 or later does not appear to be
+            available, will use pre-generated sources.])
++  fi
+ fi
+ 
+ 
+@@ -176,7 +185,7 @@ fi
+ if test "x$F77" = xno ; then
+   F77=
+ 
+-  AC_MSG_WARN([Compilation of Fortran wrappers and PGSBOX disabled])
++  AC_MSG_WARN([Compilation of Fortran wrappers and PGSBOX disabled.])
+ 
+ else
+   if test "x$F77" = x ; then
+@@ -280,7 +289,7 @@ SHRLN=
+ 
+ if test "x$ac_cv_c_compiler_gnu" = xyes ; then
+   if test "x$enable_shared" = xno ; then
+-    AC_MSG_WARN([Generation of WCS shared libraries disabled])
++    AC_MSG_WARN([Generation of WCS shared libraries disabled.])
+ 
+   else
+     SHVER=`echo "$LIBVER" | sed -e 's/\..*$//'`
+@@ -353,7 +362,7 @@ LIBDIRS=
+ AC_ARG_WITH([cfitsio], [AS_HELP_STRING([--without-cfitsio],
+             [eschew CFITSIO])], [])
+ if test "x$with_cfitsio" = xno ; then
+-  AC_MSG_WARN([CFITSIO disabled])
++  AC_MSG_WARN([CFITSIO disabled.])
+ else
+   AC_ARG_WITH([cfitsiolib], [AS_HELP_STRING([--with-cfitsiolib=DIR],
+               [directory containing cfitsio library])], [])
+@@ -379,7 +388,7 @@ fi
+ AC_ARG_WITH([pgplot], [AS_HELP_STRING([--without-pgplot],
+             [eschew PGPLOT])], [])
+ if test "x$with_pgplot" = xno ; then
+-  AC_MSG_WARN([PGPLOT disabled])
++  AC_MSG_WARN([PGPLOT disabled.])
+ else
+   AC_ARG_WITH([pgplotlib], [AS_HELP_STRING([--with-pgplotlib=DIR],
+               [directory containing pgplot library])], [])
+@@ -538,12 +547,23 @@ fi
+ AC_ARG_ENABLE([utils], [AS_HELP_STRING([--disable-utils],
+             [don't build the WCS utilities])], [])
+ if test "x$enable_utils" = xno ; then
+-  AC_MSG_WARN([Compilation of WCS utilities disabled])
++  AC_MSG_WARN([Compilation of WCS utilities disabled.])
+ else
+   SUBDIRS="$SUBDIRS utils"
+   INSTDIR="$INSTDIR utils"
+ fi
+ 
++# Default observer coordinates for sundazel.
++if test -f "$HOME/.sundazelrc"; then
++  . "$HOME/.sundazelrc"
++fi
++
++if test "x$OBSLNG" = x; then
++  OBSLNG=0.0
++  OBSLAT=0.0
++  OBSTZ=0.0
++fi
++
+ 
+ AC_SUBST([CFITSIOINC])
+ AC_SUBST([CFITSIOLIB])
+@@ -556,6 +576,10 @@ AC_SUBST([SUBDIRS])
+ AC_SUBST([TSTDIRS])
+ AC_SUBST([INSTDIR])
+ 
++AC_SUBST([OBSLNG])
++AC_SUBST([OBSLAT])
++AC_SUBST([OBSTZ])
++
+ AC_MSG_NOTICE([End of auxiliary configuration.
+ ])
+ 
+Index: astropy-4.2.1/cextern/wcslib/flavours
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/flavours
-+++ astropy-4.2/cextern/wcslib/flavours
+--- astropy-4.2.1.orig/cextern/wcslib/flavours
++++ astropy-4.2.1/cextern/wcslib/flavours
 @@ -12,7 +12,7 @@
  #
  # Reminder: add '-d' to FLFLAGS for debugging.
  #
 -# $Id: flavours,v 7.3 2020/06/03 03:37:03 mcalabre Exp $
-+# $Id: flavours,v 7.4 2021/01/31 02:24:52 mcalabre Exp $
++# $Id: flavours,v 7.6 2021/04/13 12:57:02 mcalabre Exp $
  #-----------------------------------------------------------------------------
  
  # The list of FLAVOURs can be set on the command line.
-Index: astropy-4.2/cextern/wcslib/makedefs.in
+Index: astropy-4.2.1/cextern/wcslib/makedefs.in
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/makedefs.in
-+++ astropy-4.2/cextern/wcslib/makedefs.in
+--- astropy-4.2.1.orig/cextern/wcslib/makedefs.in
++++ astropy-4.2.1/cextern/wcslib/makedefs.in
 @@ -1,5 +1,5 @@
  #-----------------------------------------------------------------------------
 -# GNU makefile definitions for building WCSLIB 7.3
-+# GNU makefile definitions for building WCSLIB 7.4
++# GNU makefile definitions for building WCSLIB 7.6
  #
  # makedefs is generated from makedefs.in by configure.  It contains variable
  # definitions and some general-purpose rules for building WCSLIB.
@@ -33775,12 +40551,12 @@ Index: astropy-4.2/cextern/wcslib/makedefs.in
  #
  #      The shared library will be installed with version number, e.g. as
 -#      libwcs.so.7.3 or libwcs.7.3.dylib with or without the symlink
-+#      libwcs.so.7.4 or libwcs.7.4.dylib with or without the symlink
++#      libwcs.so.7.6 or libwcs.7.6.dylib with or without the symlink
  #      required to make it visible to the linker (controlled by the SHRLN
  #      variable).  On Macs it is deliberately not created because its very
  #      existence precludes static linking with the cctools linker.  You can
 -#      still link dynamically by using -lwcs.7.3.
-+#      still link dynamically by using -lwcs.7.4.
++#      still link dynamically by using -lwcs.7.6.
  #
  #   4) PGPLOT is Tim Pearson's Fortran graphics library with separate C
  #      interface available from astro.caltech.edu.  It is only required by
@@ -33789,90 +40565,115 @@ Index: astropy-4.2/cextern/wcslib/makedefs.in
  # Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
  # http://www.atnf.csiro.au/people/Mark.Calabretta
 -# $Id: makedefs.in,v 7.3 2020/06/03 03:37:03 mcalabre Exp $
-+# $Id: makedefs.in,v 7.4 2021/01/31 02:24:52 mcalabre Exp $
++# $Id: makedefs.in,v 7.6 2021/04/13 12:57:02 mcalabre Exp $
  #-----------------------------------------------------------------------------
  # Version.
    LIBVER    := @LIBVER@
-Index: astropy-4.2/cextern/wcslib/wcsconfig.h.in
+@@ -168,6 +168,12 @@
+ # Libraries required by WCSLIB itself.
+   LIBS := @LIBS@
+ 
++# Default observer coordinates for sundazel.  May be set as environment
++# variables, either generally or in $HOME/.sundazelrc, which is read by
++# configure.
++  OBSLNG := @OBSLNG@
++  OBSLAT := @OBSLAT@
++  OBSTZ  := @OBSTZ@
+ 
+ #-----------------------------------------------------------------------------
+ # You shouldn't need to change anything below here.
+@@ -245,6 +251,11 @@ show :: wcsconfig.h
+ 	-@ echo '  FLIBS       := $(FLIBS)'
+ 	-@ echo '  LIBS        := $(LIBS)'
+ 	-@ echo ''
++	-@ echo 'Default observer coordinates for sundazel...'
++	-@ echo '  OBSLNG      := $(OBSLNG)'
++	-@ echo '  OBSLAT      := $(OBSLAT)'
++	-@ echo '  OBSTZ       := $(OBSTZ)'
++	-@ echo ''
+ 
+ # Code development overrides, for use in the code subdirectories.
+ FLAVOUR := @FLAVOUR@
+Index: astropy-4.2.1/cextern/wcslib/wcsconfig.h.in
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/wcsconfig.h.in
-+++ astropy-4.2/cextern/wcslib/wcsconfig.h.in
+--- astropy-4.2.1.orig/cextern/wcslib/wcsconfig.h.in
++++ astropy-4.2.1/cextern/wcslib/wcsconfig.h.in
 @@ -1,11 +1,11 @@
  /*============================================================================
  *
  * wcsconfig.h is generated from wcsconfig.h.in by 'configure'.  It contains
 -* C preprocessor macro definitions for compiling WCSLIB 7.3
-+* C preprocessor macro definitions for compiling WCSLIB 7.4
++* C preprocessor macro definitions for compiling WCSLIB 7.6
  *
  * Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
  * http://www.atnf.csiro.au/people/Mark.Calabretta
 -* $Id: wcsconfig.h.in,v 7.3 2020/06/03 03:37:03 mcalabre Exp $
-+* $Id: wcsconfig.h.in,v 7.4 2021/01/31 02:24:52 mcalabre Exp $
++* $Id: wcsconfig.h.in,v 7.6 2021/04/13 12:57:02 mcalabre Exp $
  *===========================================================================*/
  
  /* wcslib_version() is available (as of 5.0). */
-Index: astropy-4.2/cextern/wcslib/wcsconfig_f77.h.in
+Index: astropy-4.2.1/cextern/wcslib/wcsconfig_f77.h.in
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/wcsconfig_f77.h.in
-+++ astropy-4.2/cextern/wcslib/wcsconfig_f77.h.in
+--- astropy-4.2.1.orig/cextern/wcslib/wcsconfig_f77.h.in
++++ astropy-4.2.1/cextern/wcslib/wcsconfig_f77.h.in
 @@ -1,12 +1,12 @@
  /*============================================================================
  *
  * wcsconfig_f77.h is generated from wcsconfig_f77.h.in by 'configure'.  It
 -* contains C preprocessor definitions for building the WCSLIB 7.3 Fortran
-+* contains C preprocessor definitions for building the WCSLIB 7.4 Fortran
++* contains C preprocessor definitions for building the WCSLIB 7.6 Fortran
  * wrappers.
  *
  * Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
  * http://www.atnf.csiro.au/people/Mark.Calabretta
 -* $Id: wcsconfig_f77.h.in,v 7.3 2020/06/03 03:37:03 mcalabre Exp $
-+* $Id: wcsconfig_f77.h.in,v 7.4 2021/01/31 02:24:52 mcalabre Exp $
++* $Id: wcsconfig_f77.h.in,v 7.6 2021/04/13 12:57:02 mcalabre Exp $
  *===========================================================================*/
  
  /* Integer array type large enough to hold an address.  Set here to int[2] for
-Index: astropy-4.2/cextern/wcslib/wcsconfig_tests.h.in
+Index: astropy-4.2.1/cextern/wcslib/wcsconfig_tests.h.in
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/wcsconfig_tests.h.in
-+++ astropy-4.2/cextern/wcslib/wcsconfig_tests.h.in
+--- astropy-4.2.1.orig/cextern/wcslib/wcsconfig_tests.h.in
++++ astropy-4.2.1/cextern/wcslib/wcsconfig_tests.h.in
 @@ -1,12 +1,12 @@
  /*============================================================================
  *
  * wcsconfig_test.h is generated from wcsconfig_test.h.in by 'configure'.  It
 -* contains C preprocessor definitions for compiling the WCSLIB 7.3 test/demo
-+* contains C preprocessor definitions for compiling the WCSLIB 7.4 test/demo
++* contains C preprocessor definitions for compiling the WCSLIB 7.6 test/demo
  * programs.
  *
  * Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
  * http://www.atnf.csiro.au/people/Mark.Calabretta
 -* $Id: wcsconfig_tests.h.in,v 7.3 2020/06/03 03:37:03 mcalabre Exp $
-+* $Id: wcsconfig_tests.h.in,v 7.4 2021/01/31 02:24:52 mcalabre Exp $
++* $Id: wcsconfig_tests.h.in,v 7.6 2021/04/13 12:57:02 mcalabre Exp $
  *===========================================================================*/
  
  #include <wcsconfig.h>
-Index: astropy-4.2/cextern/wcslib/wcsconfig_utils.h.in
+Index: astropy-4.2.1/cextern/wcslib/wcsconfig_utils.h.in
 ===================================================================
---- astropy-4.2.orig/cextern/wcslib/wcsconfig_utils.h.in
-+++ astropy-4.2/cextern/wcslib/wcsconfig_utils.h.in
+--- astropy-4.2.1.orig/cextern/wcslib/wcsconfig_utils.h.in
++++ astropy-4.2.1/cextern/wcslib/wcsconfig_utils.h.in
 @@ -1,12 +1,12 @@
  /*============================================================================
  *
  * wcsconfig_utils.h is generated from wcsconfig_utils.h.in by 'configure'.
 -* It contains C preprocessor macro definitions for compiling the WCSLIB 7.3
-+* It contains C preprocessor macro definitions for compiling the WCSLIB 7.4
++* It contains C preprocessor macro definitions for compiling the WCSLIB 7.6
  * utilities.
  *
  * Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
  * http://www.atnf.csiro.au/people/Mark.Calabretta
 -* $Id: wcsconfig_utils.h.in,v 7.3 2020/06/03 03:37:03 mcalabre Exp $
-+* $Id: wcsconfig_utils.h.in,v 7.4 2021/01/31 02:24:52 mcalabre Exp $
++* $Id: wcsconfig_utils.h.in,v 7.6 2021/04/13 12:57:02 mcalabre Exp $
  *===========================================================================*/
  
  #include <wcsconfig.h>
-Index: astropy-4.2/CHANGES.rst
+Index: astropy-4.2.1/CHANGES.rst
 ===================================================================
---- astropy-4.2.orig/CHANGES.rst
-+++ astropy-4.2/CHANGES.rst
-@@ -330,6 +330,10 @@ Other Changes and Additions
+--- astropy-4.2.1.orig/CHANGES.rst
++++ astropy-4.2.1/CHANGES.rst
+@@ -399,6 +399,10 @@ Other Changes and Additions
  - When importing astropy without first building the extension modules first,
    raise an error directly instead of trying to auto-build. [#10883]
  
@@ -33883,10 +40684,10 @@ Index: astropy-4.2/CHANGES.rst
  
  
  4.1 (2020-10-21)
-Index: astropy-4.2/astropy/wcs/tests/data/validate.7.4.txt
+Index: astropy-4.2.1/astropy/wcs/tests/data/validate.7.4.txt
 ===================================================================
 --- /dev/null
-+++ astropy-4.2/astropy/wcs/tests/data/validate.7.4.txt
++++ astropy-4.2.1/astropy/wcs/tests/data/validate.7.4.txt
 @@ -0,0 +1,20 @@
 +HDU 1:
 +  WCS key ' ':
@@ -33908,10 +40709,10 @@ Index: astropy-4.2/astropy/wcs/tests/data/validate.7.4.txt
 +        'HZ' -> 'Hz'.
 +    - 'celfix' made the change 'In CUNIT3 : Mismatched units type
 +      'length': have 'Hz', want 'm''.
-Index: astropy-4.2/astropy/wcs/tests/test_wcs.py
+Index: astropy-4.2.1/astropy/wcs/tests/test_wcs.py
 ===================================================================
---- astropy-4.2.orig/astropy/wcs/tests/test_wcs.py
-+++ astropy-4.2/astropy/wcs/tests/test_wcs.py
+--- astropy-4.2.1.orig/astropy/wcs/tests/test_wcs.py
++++ astropy-4.2.1/astropy/wcs/tests/test_wcs.py
 @@ -22,6 +22,7 @@ from astropy.utils.exceptions import (
  from astropy.tests.helper import assert_quantity_allclose
  from astropy.io import fits
@@ -33920,12 +40721,30 @@ Index: astropy-4.2/astropy/wcs/tests/test_wcs.py
  
  
  _WCSLIB_VER = Version(_wcs.__version__)
-@@ -117,11 +118,15 @@ def test_fixes():
+@@ -104,7 +105,16 @@ class TestSpectra:
+             header = get_pkg_data_contents(
+                 os.path.join("data", "spectra", filename), encoding='binary')
+             # finally run the test.
+-            all_wcs = wcs.find_all_wcs(header)
++            with pytest.warns(None) as w:
++                all_wcs = wcs.find_all_wcs(header)
++
++            if _WCSLIB_VER >= Version('7.4'):
++                assert len(w) == 9
++                m = str(w.pop().message)
++                assert "'datfix' made the change 'Set MJD-OBS to 53925.853472 from DATE-OBS'." in m
++            else:
++                assert len(w) == 0
++
+             assert len(all_wcs) == 9
+ 
+ 
+@@ -117,11 +127,15 @@ def test_fixes():
      with pytest.raises(wcs.InvalidTransformError), pytest.warns(wcs.FITSFixedWarning) as w:
          wcs.WCS(header, translate_units='dhs')
  
 -    assert len(w) == 2
-+    if _WCSLIB_VER >= Version('7.4'):
++    if Version('7.4') <=_WCSLIB_VER < Version('7.6'):
 +        assert len(w) == 3
 +        assert "'datfix' made the change 'Success'." in str(w.pop().message)
 +    else:
@@ -33938,7 +40757,7 @@ Index: astropy-4.2/astropy/wcs/tests/test_wcs.py
  
  
  # Ignore "PV2_2 = 0.209028857410973 invalid keyvalue" warning seen on Windows.
-@@ -145,6 +150,7 @@ def test_pix2world():
+@@ -145,6 +159,7 @@ def test_pix2world():
      """
      # TODO: write this to test the expected output behavior of pix2world,
      # currently this just makes sure it doesn't error out in unexpected ways
@@ -33946,19 +40765,19 @@ Index: astropy-4.2/astropy/wcs/tests/test_wcs.py
      filename = get_pkg_data_filename('data/sip2.fits')
      with pytest.warns(wcs.FITSFixedWarning) as caught_warnings:
          # this raises a warning unimportant for this testing the pix2world
-@@ -153,7 +159,10 @@ def test_pix2world():
+@@ -153,7 +168,10 @@ def test_pix2world():
          ww = wcs.WCS(filename)
  
      # might as well monitor for changing behavior
 -    assert len(caught_warnings) == 1
-+    if _WCSLIB_VER >= Version('7.4'):
++    if Version('7.4') <=_WCSLIB_VER < Version('7.6'):
 +        assert len(caught_warnings) == 2
 +    else:
 +        assert len(caught_warnings) == 1
  
      n = 3
      pixels = (np.arange(n) * np.ones((2, n))).T
-@@ -162,18 +171,17 @@ def test_pix2world():
+@@ -162,18 +180,17 @@ def test_pix2world():
      # Catch #2791
      ww.wcs_pix2world(pixels[..., 0], pixels[..., 1], 0, ra_dec_order=True)
  
@@ -33979,11 +40798,28 @@ Index: astropy-4.2/astropy/wcs/tests/test_wcs.py
  
  
  def test_load_fits_path():
-@@ -319,13 +327,19 @@ def test_invalid_shape():
+@@ -213,7 +230,15 @@ def test_dict_init():
+     if _WCSLIB_VER >= Version('7.1'):
+         hdr['DATEREF'] = '1858-11-17'
+ 
+-    w = wcs.WCS(hdr)
++    with pytest.warns(None) as wrng:
++        w = wcs.WCS(hdr)
++
++    if _WCSLIB_VER >= Version('7.4'):
++        assert len(wrng) == 1
++        msg = str(wrng[0].message)
++        assert "'datfix' made the change 'Set MJDREF to 0.000000 from DATEREF'." in msg
++    else:
++        assert len(wrng) == 0
+ 
+     xp, yp = w.wcs_world2pix(41., 2., 0)
+ 
+@@ -319,13 +344,19 @@ def test_invalid_shape():
  
  def test_warning_about_defunct_keywords():
      header = get_pkg_data_contents('data/defunct_keywords.hdr', encoding='binary')
-+    if _WCSLIB_VER >= Version('7.4'):
++    if Version('7.4') <=_WCSLIB_VER < Version('7.6'):
 +        n_warn = 5
 +    else:
 +        n_warn = 4
@@ -34001,13 +40837,15 @@ Index: astropy-4.2/astropy/wcs/tests/test_wcs.py
              assert 'PCi_ja' in str(item.message)
  
  
-@@ -431,14 +445,14 @@ def test_find_all_wcs_crash():
+@@ -431,14 +462,16 @@ def test_find_all_wcs_crash():
  def test_validate():
      results = wcs.validate(get_pkg_data_filename("data/validate.fits"))
      results_txt = sorted(set([x.strip() for x in repr(results).splitlines()]))
 -    version = wcs._wcs.__version__
 -    if version[0] in ['6', '7']:
-+    if _WCSLIB_VER >= Version('7.4'):
++    if _WCSLIB_VER >= Version('7.6'):
++        filename = 'data/validate.7.6.txt'
++    elif _WCSLIB_VER >= Version('7.4'):
 +        filename = 'data/validate.7.4.txt'
 +    elif _WCSLIB_VER >= Version('6.0'):
          filename = 'data/validate.6.txt'
@@ -34023,7 +40861,7 @@ Index: astropy-4.2/astropy/wcs/tests/test_wcs.py
      else:
          filename = 'data/validate.txt'
      with open(get_pkg_data_filename(filename), "r") as fd:
-@@ -1457,3 +1471,47 @@ def test_no_pixel_area():
+@@ -1457,3 +1490,47 @@ def test_no_pixel_area():
  
      # Pixel scales still possible
      assert_quantity_allclose(w.proj_plane_pixel_scales(), 1)
@@ -34071,25 +40909,33 @@ Index: astropy-4.2/astropy/wcs/tests/test_wcs.py
 +        w2 = wcs.WCS(hdulist[0].header)
 +
 +    assert w.pixel_to_world(*cen).separation(w2.pixel_to_world(*(siz / 2))) < 1.e-3 * u.mas
-Index: astropy-4.2/astropy/wcs/tests/test_wcsprm.py
+Index: astropy-4.2.1/astropy/wcs/tests/test_wcsprm.py
 ===================================================================
---- astropy-4.2.orig/astropy/wcs/tests/test_wcsprm.py
-+++ astropy-4.2/astropy/wcs/tests/test_wcsprm.py
-@@ -414,6 +414,9 @@ def test_fix():
+--- astropy-4.2.1.orig/astropy/wcs/tests/test_wcsprm.py
++++ astropy-4.2.1/astropy/wcs/tests/test_wcsprm.py
+@@ -409,11 +409,17 @@ def test_fix():
+         'unitfix': 'No change',
+         'celfix': 'No change',
+         'obsfix': 'No change'}
++
+     version = wcs._wcs.__version__
+     if Version(version) <= Version('5'):
          del fix_ref['obsfix']
++
      if Version(version) >= Version('7.1'):
          w.dateref = '1858-11-17'
-+    if Version(version) >= Version('7.4'):
++
++    if Version('7.4') <= Version(version) < Version('7.6'):
 +        fix_ref['datfix'] = 'Success'
 +
      assert w.fix() == fix_ref
  
  
-Index: astropy-4.2/setup.cfg
+Index: astropy-4.2.1/setup.cfg
 ===================================================================
---- astropy-4.2.orig/setup.cfg
-+++ astropy-4.2/setup.cfg
-@@ -134,6 +134,7 @@ filterwarnings =
+--- astropy-4.2.1.orig/setup.cfg
++++ astropy-4.2.1/setup.cfg
+@@ -135,6 +135,7 @@ filterwarnings =
  	ignore:the imp module is deprecated:DeprecationWarning
  	ignore:The toolz.compatibility module is no longer needed:DeprecationWarning
  	ignore:parallel reading does not currently work, so falling back to serial
@@ -34097,10 +40943,10 @@ Index: astropy-4.2/setup.cfg
  doctest_norecursedirs = 
  	*/setup_package.py
  doctest_subpackage_requires = 
-Index: astropy-4.2/astropy/wcs/wcs.py
+Index: astropy-4.2.1/astropy/wcs/wcs.py
 ===================================================================
---- astropy-4.2.orig/astropy/wcs/wcs.py
-+++ astropy-4.2/astropy/wcs/wcs.py
+--- astropy-4.2.1.orig/astropy/wcs/wcs.py
++++ astropy-4.2.1/astropy/wcs/wcs.py
 @@ -2671,6 +2671,22 @@ reduce these to 2 dimensions using the n
              for kw in keys_to_remove:
                  if kw in header:
@@ -34124,3 +40970,134 @@ Index: astropy-4.2/astropy/wcs/wcs.py
          else:
              header = fits.Header()
  
+Index: astropy-4.2.1/docs/changes/wcs/11549.feature.rst
+===================================================================
+--- /dev/null
++++ astropy-4.2.1/docs/changes/wcs/11549.feature.rst
+@@ -0,0 +1,3 @@
++Updated bundled version of WCSLIB to version 7.6. See
++https://www.atnf.csiro.au/people/mcalabre/WCS/CHANGES for a list of
++included changes.
+Index: astropy-4.2.1/astropy/wcs/tests/data/validate.7.6.txt
+===================================================================
+--- /dev/null
++++ astropy-4.2.1/astropy/wcs/tests/data/validate.7.6.txt
+@@ -0,0 +1,19 @@
++HDU 1:
++  WCS key ' ':
++    - RADECSYS= 'ICRS ' / Astrometric system
++      the RADECSYS keyword is deprecated, use RADESYSa.
++    - The WCS transformation has more axes (2) than the image it is
++      associated with (0)
++    - Removed redundant SCAMP distortion parameters because SIP
++      parameters are also present
++    - 'datfix' made the change 'Set MJD-OBS to 55007.362083 from DATE-
++      OBS'.
++
++HDU 2:
++  WCS key ' ':
++    - The WCS transformation has more axes (3) than the image it is
++      associated with (0)
++    - 'unitfix' made the change 'Changed units:
++        'HZ' -> 'Hz'.
++    - 'celfix' made the change 'In CUNIT3 : Mismatched units type
++      'length': have 'Hz', want 'm''.
+\ No newline at end of file
+Index: astropy-4.2.1/astropy/wcs/tests/test_tab.py
+===================================================================
+--- astropy-4.2.1.orig/astropy/wcs/tests/test_tab.py
++++ astropy-4.2.1/astropy/wcs/tests/test_tab.py
+@@ -1,14 +1,20 @@
+ # Licensed under a 3-clause BSD style license - see LICENSE.rst
+ 
+-import pytest
+-
+ import numpy as np
+ 
++import pytest
++from packaging.version import Version
+ from astropy import wcs
++from astropy.wcs import _wcs  # noqa
++from astropy.io import fits
++from astropy.utils.data import get_pkg_data_filename
+ 
+ from . helper import SimModelTAB
+ 
+ 
++_WCSLIB_VER = Version(_wcs.__version__)
++
++
+ def test_2d_spatial_tab_roundtrip(tab_wcs_2di):
+     nx, ny = tab_wcs_2di.pixel_shape
+     # generate "random" test coordinates:
+@@ -37,3 +43,19 @@ def test_2d_spatial_tab_vs_model():
+     rd = w.wcs_pix2world(xy, 1)
+     rd_model = model.fwd_eval(xy)
+     assert np.allclose(rd, rd_model, rtol=0, atol=1e-7)
++
++
++@pytest.mark.skipif(
++    _WCSLIB_VER < Version('7.6'),
++    reason="Only in WCSLIB 7.6 a 1D -TAB axis roundtrips unless first axis"
++)
++def test_mixed_celest_and_1d_tab_roundtrip():
++    # Tests WCS roundtripping for the case when there is one -TAB axis and
++    # this axis is not the first axis. This tests a bug fixed in WCSLIB 7.6.
++    filename = get_pkg_data_filename('data/tab-time-last-axis.fits')
++    hdul = fits.open(filename)
++    w = wcs.WCS(hdul[0].header, hdul)
++    hdul.close()
++
++    pts = np.random.random((10, 3)) * [[2047, 2047, 127]]
++    assert np.allclose(pts, w.wcs_world2pix(w.wcs_pix2world(pts, 0), 0))
+Index: astropy-4.2.1/astropy/wcs/tests/test_utils.py
+===================================================================
+--- astropy-4.2.1.orig/astropy/wcs/tests/test_utils.py
++++ astropy-4.2.1/astropy/wcs/tests/test_utils.py
+@@ -5,6 +5,7 @@ import pytest
+ from io import StringIO
+ from itertools import product
+ 
++from packaging.version import Version
+ import numpy as np
+ from numpy.testing import assert_almost_equal, assert_equal, assert_allclose
+ 
+@@ -17,6 +18,7 @@ from astropy.coordinates import SkyCoord
+ from astropy.units import Quantity
+ from astropy.io import fits
+ 
++from astropy.wcs import _wcs  # noqa
+ from astropy.wcs.wcs import (WCS, Sip, WCSSUB_LONGITUDE, WCSSUB_LATITUDE,
+                              FITSFixedWarning)
+ from astropy.wcs.wcsapi.fitswcs import SlicedFITSWCS
+@@ -1267,16 +1269,25 @@ def test_issue10991():
+ @pytest.mark.parametrize('x_in,y_in', [[0, 0], [np.arange(5), np.arange(5)]])
+ def test_pixel_to_world_itrs(x_in, y_in):
+     """Regression test for https://github.com/astropy/astropy/pull/9609"""
+-    wcs = WCS({'NAXIS': 2,
+-               'CTYPE1': 'TLON-CAR',
+-               'CTYPE2': 'TLAT-CAR',
+-               'RADESYS': 'ITRS ',
+-               'DATE-OBS': '2017-08-17T12:41:04.444'})
++    with pytest.warns(None) as w:
++        wcs = WCS({'NAXIS': 2,
++                   'CTYPE1': 'TLON-CAR',
++                   'CTYPE2': 'TLAT-CAR',
++                   'RADESYS': 'ITRS ',
++                   'DATE-OBS': '2017-08-17T12:41:04.444'})
++
++    if Version(_wcs.__version__) >= Version('7.4'):
++        assert len(w) == 1
++        msg = str(w[0].message)
++        assert "'datfix' made the change 'Set MJD-OBS to 57982.528524 from DATE-OBS'." in msg
++    else:
++        assert len(w) == 0
+ 
+     # This shouldn't raise an exception.
+     coord = wcs.pixel_to_world(x_in, y_in)
+ 
+     # Check round trip transformation.
+     x, y = wcs.world_to_pixel(coord)
++
+     np.testing.assert_almost_equal(x, x_in)
+     np.testing.assert_almost_equal(y, y_in)
diff --git a/python-astropy.changes b/python-astropy.changes
index 33b34be..53ac0dc 100644
--- a/python-astropy.changes
+++ b/python-astropy.changes
@@ -1,3 +1,13 @@
+-------------------------------------------------------------------
+Sun Jul  4 13:26:14 UTC 2021 - Ben Greiner <code@bnavigator.de>
+
+- Replace astropy-pr11260-wcsfailures.patch with
+  astropy-pr11260+pr11549-wcs76.patch
+  * fixes test failures because of the recent Tumbleweed update to
+    wcslib 7.6
+  * include binary test file tab-time-last-axis.fits from
+    gh#astropy/astropy#11549, which does not fit into the patchfile
+
 -------------------------------------------------------------------
 Sat Apr 17 15:30:57 UTC 2021 - Ben Greiner <code@bnavigator.de>
 
diff --git a/python-astropy.spec b/python-astropy.spec
index 55f0d82..fd20ab2 100644
--- a/python-astropy.spec
+++ b/python-astropy.spec
@@ -1,5 +1,5 @@
 #
-# spec file for package python-astropy-test
+# spec file
 #
 # Copyright (c) 2021 SUSE LLC
 #
@@ -52,11 +52,13 @@ URL:            https://astropy.org
 Source:         https://files.pythonhosted.org/packages/source/a/astropy/astropy-%{version}.tar.gz
 # belongs to Patch1 --  gh/astropy/astropy#11260
 Source1:        https://github.com/dhomeier/astropy/raw/wcs-distortion-headers/astropy/wcs/tests/data/dss.14.29.56-62.41.05.fits.gz
+# belongs to Patch1 --  gh/astropy/astropy#11549
+Source2:        https://github.com/mcara/astropy/raw/wcslib7p6/astropy/wcs/tests/data/tab-time-last-axis.fits
 # Mark wcs headers as false positives for devel-file-in-non-devel-package
 # These are used by the python files so they must be available.
 Source100:      python-astropy-rpmlintrc
-# PATCH-FIX-UPSTREAM astropy-pr11260-wcsfailures.patch -- gh/astropy/astropy#11260
-Patch1:         astropy-pr11260-wcsfailures.patch
+# PATCH-FIX-UPSTREAM astropy-pr11260+pr11549-wcs76.patch -- gh/astropy/astropy#11260 + gh/astropy/astropy#11549
+Patch1:         astropy-pr11260+pr11549-wcs76.patch
 # https://docs.astropy.org/en/v4.1/install.html#requirements
 BuildRequires:  %{python_module Cython >= 0.21}
 BuildRequires:  %{python_module Jinja2}
@@ -137,7 +139,7 @@ managing them.
 %prep
 %autosetup -p1 -n astropy-%{version}
 
-cp %{SOURCE1} astropy/wcs/tests/data/
+cp %{SOURCE1} %{SOURCE2} astropy/wcs/tests/data/
 
 %if %{with systemlibs}
 # Make sure bundled libs are not used
diff --git a/tab-time-last-axis.fits b/tab-time-last-axis.fits
new file mode 100644
index 0000000..c6648a1
--- /dev/null
+++ b/tab-time-last-axis.fits
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:d2913b3cc917dcec8f9566c20b06acdfa610acca2087578d2097f69f6d710561
+size 14400