>From cdd328f232a93fb40aec25d0681ef191eaeba2da Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering@redhat.com>
Date: Sun, 16 Oct 2011 10:35:56 +0200
Subject: [PATCH 1/3] maint: tac: remove sole use of sprintf in favor of
 stpcpy

* src/tac.c (copy_to_temp): Use stpcpy rather than sprintf.
Move some declarations "down" to point of initialization.
---
 src/tac.c |   17 +++++++----------
 1 files changed, 7 insertions(+), 10 deletions(-)

Index: src/tac.c
===================================================================
--- src/tac.c.orig	2011-02-19 18:17:03.000000000 +0100
+++ src/tac.c	2011-10-17 15:46:27.879485098 +0200
@@ -426,20 +426,17 @@ copy_to_temp (FILE **g_tmp, char **g_tem
 {
   static char *template = NULL;
   static char const *tempdir;
-  char *tempfile;
-  FILE *tmp;
-  int fd;
 
   if (template == NULL)
     {
-      char const * const Template = "%s/tacXXXXXX";
+      char const * const Template = "tacXXXXXX";
       tempdir = getenv ("TMPDIR");
       if (tempdir == NULL)
         tempdir = DEFAULT_TMPDIR;
 
-      /* Subtract 2 for `%s' and add 1 for the trailing NUL byte.  */
-      template = xmalloc (strlen (tempdir) + strlen (Template) - 2 + 1);
-      sprintf (template, Template, tempdir);
+      /* Add 1 for the slash and one for the trailing NUL byte.  */
+      template = xmalloc (strlen (tempdir) + strlen (Template) + 1 + 1);
+      stpcpy (stpcpy (stpcpy (template, tempdir), "/"), Template);
     }
 
   /* FIXME: there's a small window between a successful mkstemp call
@@ -451,21 +448,23 @@ copy_to_temp (FILE **g_tmp, char **g_tem
      FIXME: clean up upon fatal signal.  Don't block them, in case
      $TMPFILE is a remote file system.  */
 
-  tempfile = template;
-  fd = mkstemp (template);
+  char *tempfile = xstrdup (template);
+  int fd = mkstemp (tempfile);
   if (fd < 0)
     {
       error (0, errno, _("cannot create temporary file in %s"),
              quote (tempdir));
+      free (tempfile);
       return false;
     }
 
-  tmp = fdopen (fd, (O_BINARY ? "w+b" : "w+"));
+  FILE *tmp = fdopen (fd, (O_BINARY ? "w+b" : "w+"));
   if (! tmp)
     {
       error (0, errno, _("cannot open %s for writing"), quote (tempfile));
       close (fd);
       unlink (tempfile);
+      free (tempfile);
       return false;
     }
 
@@ -501,6 +500,7 @@ copy_to_temp (FILE **g_tmp, char **g_tem
 
  Fail:
   fclose (tmp);
+  free (tempfile);
   return false;
 }
 
@@ -512,8 +512,14 @@ tac_nonseekable (int input_fd, const cha
 {
   FILE *tmp_stream;
   char *tmp_file;
-  return (copy_to_temp (&tmp_stream, &tmp_file, input_fd, file)
-          && tac_seekable (fileno (tmp_stream), tmp_file));
+
+  if (!copy_to_temp (&tmp_stream, &tmp_file, input_fd, file))
+    return false;
+
+  bool ok = tac_seekable (fileno (tmp_stream), tmp_file);
+  fclose (tmp_stream);
+  free (tmp_file);
+  return ok;
 }
 
 /* Print FILE in reverse, copying it to a temporary
Index: tests/Makefile.am
===================================================================
--- tests/Makefile.am.orig	2011-10-17 15:40:44.533154336 +0200
+++ tests/Makefile.am	2011-10-17 15:40:44.882149592 +0200
@@ -270,6 +270,7 @@ TESTS =						\
   misc/sum-sysv					\
   misc/tac					\
   misc/tac-continue				\
+  misc/tac-2-nonseekable			\
   misc/tail					\
   misc/tee					\
   misc/tee-dash					\
Index: tests/misc/tac-2-nonseekable
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ tests/misc/tac-2-nonseekable	2011-10-17 15:40:44.883149578 +0200
@@ -0,0 +1,27 @@
+#!/bin/sh
+# ensure that tac works with two or more non-seekable inputs
+
+# Copyright (C) 2011 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../src
+print_ver_ tac
+
+echo x | tac - - > out 2> err || fail=1
+echo x > exp || fail=1
+compare out exp || fail=1
+compare err /dev/null || fail=1
+
+Exit $fail