X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;ds=inline;f=lib%2Frename.c;h=8dcd3e514861bd75a10b4cb17fc0667095c02dd8;hb=93627d90a57bd8190dc5adc94685b7e2d96d9312;hp=a40bbb5ae77d4b0886345a1b5d539d869f49f0c9;hpb=d87c39464604e74f580c7fae835be31a4c125c36;p=gnulib.git

diff --git a/lib/rename.c b/lib/rename.c
index a40bbb5ae..8dcd3e514 100644
--- a/lib/rename.c
+++ b/lib/rename.c
@@ -1,4 +1,4 @@
-/* rename.c -- BSD compatible directory function for System V
+/* BSD compatible rename and directory rename function for System V.
    Copyright (C) 1988, 1990 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
@@ -12,60 +12,94 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+#if 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
 
+#if STAT_MACROS_BROKEN
+# undef S_ISDIR
+#endif
+
 #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.
    Return 0 if successful, -1 if not. */
 
 int
-rename (from, to)
-     char *from;
-     char *to;
+rename (char *from, char *to)
 {
-  struct stat from_stats;
-  int pid, status;
+  struct stat from_stats, to_stats;
 
   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;
+    }
+
+#ifdef MVDIR
+
+/* If MVDIR is defined, it should be the full filename of a setuid root
+   program able to link and unlink directories.  If MVDIR is not defined,
+   then the capability of renaming directories may be missing.  */
 
   if (S_ISDIR (from_stats.st_mode))
     {
       /* Need a setuid root process to link and unlink directories. */
-      pid = fork ();
+      int status;
+      pid_t pid = fork ();
       switch (pid)
 	{
 	case -1:		/* Error. */
-	  error (1, errno, "cannot fork");
+	  return -1;		/* errno already set */
 
 	case 0:			/* Child. */
 	  execl (MVDIR, "mvdir", from, to, (char *) 0);
-	  error (255, errno, "cannot run `%s'", MVDIR);
+	  _exit (1);
 
 	default:		/* Parent. */
 	  while (wait (&status) != pid)
 	    /* Do nothing. */ ;
 
-	  errno = 0;		/* mvdir printed the system error message. */
 	  if (status)
-	    return -1;
+	    {
+	      /* MVDIR failed.  */
+	      errno = EIO;
+	      return -1;
+	    }
 	}
     }
   else
+
+#endif /* MVDIR */
+
     {
       if (link (from, to))
 	return -1;