From 5ecdd461349e34ef74c4293c397cc1d7b9b9b824d2d19190c115da9a1f08408e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michael=20Schr=C3=B6der?= <mls@suse.com>
Date: Fri, 12 Feb 2021 15:20:59 +0000
Subject: [PATCH] Fix double width combining char handling that could lead to a
 segfault [bnc#1182092]

OBS-URL: https://build.opensuse.org/package/show/Base:System/screen?expand=0&rev=96
---
 combchar.diff  | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++
 screen.changes |  7 +++++
 screen.spec    |  4 ++-
 3 files changed, 90 insertions(+), 1 deletion(-)
 create mode 100644 combchar.diff

diff --git a/combchar.diff b/combchar.diff
new file mode 100644
index 0000000..2b2eb65
--- /dev/null
+++ b/combchar.diff
@@ -0,0 +1,80 @@
+--- ./ansi.c.orig	2017-10-23 11:32:41.000000000 +0000
++++ ./ansi.c	2021-02-12 14:41:05.565447682 +0000
+@@ -692,10 +692,6 @@ register int len;
+ 		    }
+ 		  curr->w_rend.font = 0;
+ 		}
+-#  ifdef DW_CHARS
+-	      if (curr->w_encoding == UTF8 && utf8_isdouble(c))
+-		curr->w_mbcs = 0xff;
+-#  endif
+ 	      if (curr->w_encoding == UTF8 && c >= 0x0300 && utf8_iscomb(c))
+ 		{
+ 		  int ox, oy;
+@@ -730,6 +726,10 @@ register int len;
+ 		    }
+ 		  break;
+ 		}
++#  ifdef DW_CHARS
++	      if (curr->w_encoding == UTF8 && utf8_isdouble(c))
++		curr->w_mbcs = 0xff;
++#  endif
+ 	      font = curr->w_rend.font;
+ # endif
+ # ifdef DW_CHARS
+--- ./encoding.c.orig	2017-10-23 11:32:41.000000000 +0000
++++ ./encoding.c	2021-02-12 15:10:48.660858878 +0000
+@@ -43,7 +43,7 @@ static int  encmatch __P((char *, char *
+ # ifdef UTF8
+ static int   recode_char __P((int, int, int));
+ static int   recode_char_to_encoding __P((int, int));
+-static void  comb_tofront __P((int, int));
++static void  comb_tofront __P((int));
+ #  ifdef DW_CHARS
+ static int   recode_char_dw __P((int, int *, int, int));
+ static int   recode_char_dw_to_encoding __P((int, int *, int));
+@@ -1256,6 +1256,8 @@ int c;
+     {0x30000, 0x3FFFD},
+   };
+ 
++  if (c >= 0xdf00 && c <= 0xdfff)
++    return 1;          /* dw combining sequence */
+   return ((bisearch(c, wide, sizeof(wide) / sizeof(struct interval) - 1)) ||
+           (cjkwidth &&
+            bisearch(c, ambiguous,
+@@ -1323,11 +1325,12 @@ int c;
+ }
+ 
+ static void
+-comb_tofront(root, i)
+-int root, i;
++comb_tofront(i)
++int i;
+ {
+   for (;;)
+     {
++      int root = i >= 0x700 ? 0x801 : 0x800;
+       debug1("bring to front: %x\n", i);
+       combchars[combchars[i]->prev]->next = combchars[i]->next;
+       combchars[combchars[i]->next]->prev = combchars[i]->prev;
+@@ -1389,9 +1392,9 @@ struct mchar *mc;
+     {
+       /* full, recycle old entry */
+       if (c1 >= 0xd800 && c1 < 0xe000)
+-        comb_tofront(root, c1 - 0xd800);
++        comb_tofront(c1 - 0xd800);
+       i = combchars[root]->prev;
+-      if (c1 == i + 0xd800)
++      if (i == 0x800 || i == 0x801 || c1 == i + 0xd800)
+ 	{
+ 	  /* completely full, can't recycle */
+ 	  debug("utf8_handle_comp: completely full!\n");
+@@ -1415,7 +1418,7 @@ struct mchar *mc;
+   mc->font  = (i >> 8) + 0xd8;
+   mc->fontx = 0;
+   debug3("combinig char %x %x -> %x\n", c1, c, i + 0xd800);
+-  comb_tofront(root, i);
++  comb_tofront(i);
+ }
+ 
+ #else /* !UTF8 */
diff --git a/screen.changes b/screen.changes
index a515c66..6047318 100644
--- a/screen.changes
+++ b/screen.changes
@@ -1,3 +1,10 @@
+-------------------------------------------------------------------
+Fri Feb 12 15:37:48 CET 2021 - mls@suse.de
+
+- Fix double width combining char handling that could lead
+  to a segfault [bnc#1182092]
+  new patch: combchar.diff
+
 -------------------------------------------------------------------
 Mon Nov 30 13:38:31 UTC 2020 - Dominique Leuenberger <dimstar@opensuse.org>
 
diff --git a/screen.spec b/screen.spec
index a7f566e..75ed3f1 100644
--- a/screen.spec
+++ b/screen.spec
@@ -1,7 +1,7 @@
 #
 # spec file for package screen
 #
-# Copyright (c) 2020 SUSE LLC
+# Copyright (c) 2021 SUSE LLC
 #
 # All modifications and additions to the file contributed by third parties
 # remain the property of their copyright owners, unless otherwise agreed
@@ -35,6 +35,7 @@ Source3:        https://savannah.gnu.org/project/memberlist-gpgkeys.php?group=sc
 Source4:        screen.pam
 Patch0:         global_screenrc.patch
 Patch6:         libtinfo.diff
+Patch7:         combchar.diff
 BuildRequires:  autoconf
 BuildRequires:  automake
 BuildRequires:  ncurses-devel
@@ -67,6 +68,7 @@ Documentation: man page
 %patch0
 # libtinfo.diff
 %patch6
+%patch7
 
 %build
 sh ./autogen.sh