From: Jim Meyering <meyering@redhat.com>
Date: Sat, 10 May 2008 13:19:43 +0000 (+0200)
Subject: Make chdir-safer.c more efficient on a system with no symlinks.
X-Git-Tag: v0.1~7416
X-Git-Url: http://erislabs.org.uk/gitweb/?a=commitdiff_plain;h=ff0b56d949424acc0ea32b546bf8b32f98153d63;p=gnulib.git

Make chdir-safer.c more efficient on a system with no symlinks.

* lib/chdir-safer.c (chdir_no_follow): Skip lstat and fstat calls
also if ELOOP is zero.  Suggested by Bruno Haible.
---

diff --git a/ChangeLog b/ChangeLog
index 67653c119..4f7483a08 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2008-05-10  Jim Meyering  <meyering@redhat.com>
 
+	Make chdir-safer.c more efficient on a system with no symlinks.
+	* lib/chdir-safer.c (chdir_no_follow): Skip lstat and fstat calls
+	also if ELOOP is zero.  Suggested by Bruno Haible.
+
 	Make chdir-safer.c slightly safer.
 	* lib/chdir-safer.c (chdir_no_follow): Test HAVE_WORKING_O_NOFOLLOW,
 	not O_NOFOLLOW, in case the latter is nonzero and open ignores it.
diff --git a/lib/chdir-safer.c b/lib/chdir-safer.c
index a5c9a4d12..03f372050 100644
--- a/lib/chdir-safer.c
+++ b/lib/chdir-safer.c
@@ -50,8 +50,10 @@ chdir_no_follow (char const *dir)
   /* If open follows symlinks, lstat DIR and fstat FD to ensure that
      they are the same file; if they are different files, set errno to
      ELOOP (the same value that open uses for symlinks with
-     O_NOFOLLOW) so the caller can report a failure.  */
-  if (! HAVE_WORKING_O_NOFOLLOW)
+     O_NOFOLLOW) so the caller can report a failure.
+     Skip this check if ELOOP == 0, which should be the case
+     on any system that lacks symlink support.  */
+  if (ELOOP && ! HAVE_WORKING_O_NOFOLLOW)
     {
       struct stat sb1;
       result = lstat (dir, &sb1);