grep: port O_NOFOLLOW errno checking to NetBSD

Problem reported by Assaf Gordon in: http://bugs.gnu.org/18892
* NEWS: Document it.
* src/grep.c (open_symlink_nofollow_error):
New function, which does the right thing on NetBSD.
(grepfile): Use it.

2 files changed, 19 insertions, 1 deletions

diff --git a/NEWS b/NEWS
index 183b7f0b..c4651627 100644
--- a/NEWS
+++ b/NEWS
@@ -48,6 +48,10 @@ GNU grep NEWS                                    -*- outline -*-
   grep -E rejected unmatched ')', instead of treating it like '\)'.
   [bug present since "the beginning"]
 
+  On NetBSD, grep -r no longer reports "Inappropriate file type or format"
+  when refusing to follow a symbolic link.
+  [bug introduced in grep-2.12]
+
 ** Changes in behavior
 
   The GREP_OPTIONS environment variable is now obsolescent, and grep
diff --git a/src/grep.c b/src/grep.c
index 0a4ac277..8dbf86ec 100644
--- a/src/grep.c
+++ b/src/grep.c
@@ -1513,13 +1513,27 @@ grepdirent (FTS *fts, FTSENT *ent, bool command_line)
   return grepfile (dirdesc, ent->fts_accpath, follow, command_line);
 }
 
+/* True if errno is ERR after 'open ("symlink", ... O_NOFOLLOW ...)'.
+   POSIX specifies ELOOP, but it's EMLINK on FreeBSD and EFTYPE on NetBSD.  */
+static bool
+open_symlink_nofollow_error (int err)
+{
+  if (err == ELOOP || err == EMLINK)
+    return true;
+#ifdef EFTYPE
+  if (err == EFTYPE)
+    return true;
+#endif
+  return false;
+}
+
 static bool
 grepfile (int dirdesc, char const *name, bool follow, bool command_line)
 {
   int desc = openat_safer (dirdesc, name, O_RDONLY | (follow ? 0 : O_NOFOLLOW));
   if (desc < 0)
     {
-      if (follow || (errno != ELOOP && errno != EMLINK))
+      if (follow || ! open_symlink_nofollow_error (errno))
         suppressible_error (filename, errno);
       return true;
     }