From: Paul Eggert <eggert@cs.ucla.edu>
Date: Mon, 7 Mar 2011 23:40:32 +0000 (-0800)
Subject: --atime-preserve=replace: fix correctness and performance bugs
X-Git-Url: https://git.dogcows.com/gitweb?p=chaz%2Ftar;a=commitdiff_plain;h=881e5626c5db79d825a45ba15aecec9087bcd8b9

--atime-preserve=replace: fix correctness and performance bugs

reported by Eric Blake in
<http://lists.gnu.org/archive/html/bug-tar/2011-03/msg00000.html>.
* src/compare.c (diff_file): Do not restore atime of size-zero files.
* src/create.c (dump_file0): Likewise.  Also, do not restore atime
when fd is zero, because that indicates a file we haven't opened.
---

diff --git a/src/compare.c b/src/compare.c
index 91ced57..273269a 100644
--- a/src/compare.c
+++ b/src/compare.c
@@ -234,7 +234,8 @@ diff_file (void)
 	      else
 		read_and_process (&current_stat_info, process_rawdata);
 
-	      if (atime_preserve_option == replace_atime_preserve)
+	      if (atime_preserve_option == replace_atime_preserve
+		  && stat_data.st_size != 0)
 		{
 		  struct timespec atime = get_stat_atime (&stat_data);
 		  if (set_file_atime (diff_handle, chdir_fd, file_name, atime)
@@ -528,7 +529,7 @@ verify_volume (void)
   if (may_fail)
     WARN((0, 0,
 	  _("Verification may fail to locate original files.")));
-  
+
   if (!diff_buffer)
     diff_init ();
 
diff --git a/src/create.c b/src/create.c
index e8de6b9..43b5a4c 100644
--- a/src/create.c
+++ b/src/create.c
@@ -1797,6 +1797,7 @@ dump_file0 (struct tar_stat_info *st, char const *name, char const *p)
 	      set_exit_status (TAREXIT_DIFFERS);
 	    }
 	  else if (atime_preserve_option == replace_atime_preserve
+		   && fd && (is_dir || original_size != 0)
 		   && set_file_atime (fd, parentfd, name, st->atime) != 0)
 	    utime_error (p);
 	}