Re: no feedback on snapshot? coreutils-7.5 coming soon

[Jim Meyering]

Pádraig Brady wrote:
> I was wondering about printing the warning,
> and was wary about now silently not preserving symlink times.
> I.E. being silently inconsistent. I guess it's better
> to be quiet in this case? That also means I can
> reinstate the mv/part-symlink test on systems without utimensat().
> Updated patch attached.

I too had my doubts initially, but then noticed that rsync is also
silent about this.

I pushed your change with a few small log/comment tweaks.
Thanks again!

>From f0a1f0df2295aaed418f201bbec67df120e1ac17 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A1draig=20Brady?= <address@hidden>
Date: Thu, 13 Aug 2009 10:39:10 +0100
Subject: [PATCH] cp,mv: fix issues with preserving timestamps of copied symlinks

* src/copy.c (copy_internal): On systems without utimensat don't
use utimens on a symlink, as that would dereference the symlink.
* tests/cp/abuse: To work around possible attribute preservation
failures breaking the test, use cp -dR rather than cp -a.
---
 src/copy.c     |   19 +++++++++++--------
 tests/cp/abuse |    2 +-
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/src/copy.c b/src/copy.c
index bed90c4..bf9230b 100644
--- a/src/copy.c
+++ b/src/copy.c
@@ -118,18 +118,18 @@ static bool owner_failure_ok (struct cp_options const *x);
 static char const *top_level_src_name;
 static char const *top_level_dst_name;

-/* Wrap utimensat-with-AT_FDCWD and utimens, to keep these
-   cpp directives out of the main code.  */
+/* Set the timestamp of symlink, FILE, to TIMESPEC.
+   If this system lacks support for that, simply return 0.  */
 static inline int
-utimensat_if_possible (char const *file, struct timespec const *timespec)
+utimens_symlink (char const *file, struct timespec const *timespec)
 {
-  return
 #if HAVE_UTIMENSAT
-    utimensat (AT_FDCWD, file, timespec, AT_SYMLINK_NOFOLLOW)
+  return utimensat (AT_FDCWD, file, timespec, AT_SYMLINK_NOFOLLOW);
 #else
-    utimens (file, timespec)
+  /* Don't set errno=ENOTSUP here as we don't want
+     to output an error message for this case.  */
+  return 0;
 #endif
-    ;
 }

 /* Perform the O(1) btrfs clone operation, if possible.
@@ -2117,7 +2117,10 @@ copy_internal (char const *src_name, char const 
*dst_name,
       timespec[0] = get_stat_atime (&src_sb);
       timespec[1] = get_stat_mtime (&src_sb);

-      if (utimensat_if_possible (dst_name, timespec) != 0)
+      if ((dest_is_symlink
+          ? utimens_symlink (dst_name, timespec)
+          : utimens (dst_name, timespec))
+         != 0)
        {
          error (0, errno, _("preserving times for %s"), quote (dst_name));
          if (x->require_preserve)
diff --git a/tests/cp/abuse b/tests/cp/abuse
index 285c531..e9086b8 100755
--- a/tests/cp/abuse
+++ b/tests/cp/abuse
@@ -37,7 +37,7 @@ for i in dangling-dest existing-dest; do
   test $i = existing-dest && echo i > t
   test $i = dangling-dest && rm -f t

-  cp -a a/1 b/1 c 2> out && fail=1
+  cp -dR a/1 b/1 c 2> out && fail=1

   compare out exp || fail=1

--
1.6.4.357.gfd68c