[PATCH] utimens: remove dependency on dup2

[Paul Eggert]

* lib/utimens.c (fdutimens): Don't invoke dup2; it's not needed
to work around the Linux kernel bug.
* modules/utimens (Depends-on): Remove dup2.
---
 ChangeLog       |    7 +++++++
 lib/utimens.c   |   13 ++++---------
 modules/utimens |    1 -
 3 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index a2e395d..382b79c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2011-09-18  Paul Eggert  <egg...@cs.ucla.edu>
+
+       utimens: remove dependency on dup2
+       * lib/utimens.c (fdutimens): Don't invoke dup2; it's not needed
+       to work around the Linux kernel bug.
+       * modules/utimens (Depends-on): Remove dup2.
+
 2011-09-18  Bruno Haible  <br...@clisp.org>
 
        inet_ntop, inet_pton: Look for it also in libresolv.
diff --git a/lib/utimens.c b/lib/utimens.c
index c190411..f7cb8de 100644
--- a/lib/utimens.c
+++ b/lib/utimens.c
@@ -180,18 +180,13 @@ fdutimens (int fd, char const *file, struct timespec 
const timespec[2])
   if (adjustment_needed < 0)
     return -1;
 
-  /* Require that at least one of FD or FILE are valid.  Works around
+  /* Require that at least one of FD or FILE are potentially valid, to avoid
      a Linux bug where futimens (AT_FDCWD, NULL) changes "." rather
      than failing.  */
-  if (!file)
+  if (fd < 0 && !file)
     {
-      if (fd < 0)
-        {
-          errno = EBADF;
-          return -1;
-        }
-      if (dup2 (fd, fd) != fd)
-        return -1;
+      errno = EBADF;
+      return -1;
     }
 
   /* Some Linux-based NFS clients are buggy, and mishandle time stamps
diff --git a/modules/utimens b/modules/utimens
index 1a9687f..c607608 100644
--- a/modules/utimens
+++ b/modules/utimens
@@ -9,7 +9,6 @@ m4/utimens.m4
 m4/utimes.m4
 
 Depends-on:
-dup2
 errno
 lstat
 gettime
-- 
1.7.4.4