File sed-follow-symlinks-stdin.patch of Package sed

This is a backport of the fix itself.

From e387009c78fa08aaebf5192a3ceeb04dcfc7781d Mon Sep 17 00:00:00 2001
From: Stanislav Brabec <sbrabec@suse.com>
Date: Mon, 13 Jul 2015 22:59:17 +0200
Subject: [PATCH] sed: fix --follow-symlinks to work when reading stdin

When reading from stdin, use of --follow-symlinks would cause failure:

  $ echo abc | sed --follow-symlinks s/a/d/
  sed: cannot stat -: No such file or directory

* sed/execute.c (open_next_file): Set input->in_file_name earlier,
so we can rearrange logic to avoid calling follow_symlink("-").
* testsuite/follow-symlinks-stdin.sh: New file.
* testsuite/Makefile.am (T): Add it.
* NEWS (Bug fixes): Mention it.
Bug introduced by commit v4.2.1-13-g84066bf.
http://bugs.gnu.org/20795
---
 NEWS                               |  3 +++
 sed/execute.c                      | 24 +++++++++++++-----------
 testsuite/Makefile.am              |  1 +
 testsuite/follow-symlinks-stdin.sh | 29 +++++++++++++++++++++++++++++
 4 files changed, 46 insertions(+), 11 deletions(-)
 create mode 100755 testsuite/follow-symlinks-stdin.sh

Index: sed-4.2.2/sed/execute.c
===================================================================
--- sed-4.2.2.orig/sed/execute.c
+++ sed-4.2.2/sed/execute.c
@@ -580,6 +580,7 @@ open_next_file(name, input)
 {
   buffer.length = 0;
 
+  input->in_file_name = name;
   if (name[0] == '-' && name[1] == '\0')
     {
       if (in_place_extension)
@@ -592,22 +593,23 @@ open_next_file(name, input)
       input->fp = stdin;
 #endif
     }
-  else if ( ! (input->fp = ck_fopen(name, read_mode, false)) )
+  else
     {
-      const char *ptr = strerror(errno);
-      fprintf(stderr, _("%s: can't read %s: %s\n"), myname, name, ptr);
-      input->read_fn = read_always_fail; /* a redundancy */
-      ++input->bad_count;
-      return;
+      if (follow_symlinks)
+        input->in_file_name = follow_symlink (name);
+
+      if ( ! (input->fp = ck_fopen (name, read_mode, false)) )
+        {
+          const char *ptr = strerror (errno);
+          fprintf (stderr, _("%s: can't read %s: %s\n"), myname, name, ptr);
+          input->read_fn = read_always_fail; /* a redundancy */
+          ++input->bad_count;
+          return;
+        }
     }
 
   input->read_fn = read_file_line;
 
-  if (follow_symlinks)
-    input->in_file_name = follow_symlink (name);
-  else
-    input->in_file_name = name;
-
   if (in_place_extension)
     {
       int input_fd;