X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Frename.c;h=44821c94fc18e73977276317ed8baaff51c1b5ba;hb=17a8c8730f659a037042fd56335ed9280cc2d387;hp=a40bbb5ae77d4b0886345a1b5d539d869f49f0c9;hpb=d87c39464604e74f580c7fae835be31a4c125c36;p=gnulib.git

diff --git a/lib/rename.c b/lib/rename.c
index a40bbb5ae..44821c94f 100644
--- a/lib/rename.c
+++ b/lib/rename.c
@@ -15,15 +15,23 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <errno.h>
-#ifndef STDC_HEADERS
+#ifndef errno
 extern int errno;
 #endif
 
+#ifdef STAT_MACROS_BROKEN
+#undef S_ISDIR
+#endif /* STAT_MACROS_BROKEN.  */
+
 #if !defined(S_ISDIR) && defined(S_IFDIR)
-#define	S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
+#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
 #endif
 
 /* Rename file FROM to file TO.
@@ -34,14 +42,30 @@ rename (from, to)
      char *from;
      char *to;
 {
-  struct stat from_stats;
+  struct stat from_stats, to_stats;
   int pid, status;
 
   if (stat (from, &from_stats))
     return -1;
 
-  if (unlink (to) && errno != ENOENT)
-    return -1;
+  /* Be careful not to unlink `from' if it happens to be equal to `to' or
+     (on filesystems that silently truncate filenames after 14 characters)
+     if `from' and `to' share the significant characters. */
+  if (stat (to, &to_stats))
+    {
+      if (errno != ENOENT)
+        return -1;
+    }
+  else
+    {
+      if ((from_stats.st_dev == to_stats.st_dev)
+          && (from_stats.st_ino == to_stats.st_ino))
+        /* `from' and `to' designate the same file on that filesystem. */
+        return 0;
+
+      if (unlink (to) && errno != ENOENT)
+        return -1;
+    }
 
   if (S_ISDIR (from_stats.st_mode))
     {