X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fsame.c;h=ecbc58fdbeb69b1c47ade0dc980602189df32310;hb=4cd40eed210c4e43d3f741f17e6c4263f41d0c5f;hp=7dad198671a3eeb2adac22024f74b7fb161d0850;hpb=3c634821894104eaaeaa6a21f615262bf6535462;p=gnulib.git

diff --git a/lib/same.c b/lib/same.c
index 7dad19867..ecbc58fdb 100644
--- a/lib/same.c
+++ b/lib/same.c
@@ -1,5 +1,7 @@
 /* Determine whether two file names refer to the same file.
-   Copyright (C) 1997-2000, 2002-2003 Free Software Foundation, Inc.
+
+   Copyright (C) 1997, 1998, 1999, 2000, 2002, 2003, 2004 Free
+   Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -13,7 +15,7 @@
 
    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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
 
 /* written by Jim Meyering */
 
@@ -21,6 +23,7 @@
 # include <config.h>
 #endif
 
+#include <stdbool.h>
 #include <stdio.h>
 #ifdef HAVE_UNISTD_H
 # include <unistd.h>
@@ -30,17 +33,23 @@
 #include <sys/stat.h>
 #include <ctype.h>
 #include <errno.h>
-#ifndef errno
-extern int errno;
-#endif
 
 #include <string.h>
 
+#include <limits.h>
+#ifndef _POSIX_NAME_MAX
+# define _POSIX_NAME_MAX 14
+#endif
+
 #include "same.h"
 #include "dirname.h"
 #include "error.h"
 #include "xalloc.h"
 
+#ifndef MIN
+# define MIN(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
 #define SAME_INODE(Stat_buf_1, Stat_buf_2) \
   ((Stat_buf_1).st_ino == (Stat_buf_2).st_ino \
    && (Stat_buf_1).st_dev == (Stat_buf_2).st_dev)
@@ -48,7 +57,7 @@ extern int errno;
 /* Return nonzero if SOURCE and DEST point to the same name in the same
    directory.  */
 
-int
+bool
 same_name (const char *source, const char *dest)
 {
   /* Compare the basenames.  */
@@ -56,9 +65,24 @@ same_name (const char *source, const char *dest)
   char const *dest_basename = base_name (dest);
   size_t source_baselen = base_len (source_basename);
   size_t dest_baselen = base_len (dest_basename);
+  bool identical_basenames =
+    (source_baselen == dest_baselen
+     && memcmp (source_basename, dest_basename, dest_baselen) == 0);
+  bool compare_dirs = identical_basenames;
+  bool same = false;
+
+#if ! _POSIX_NO_TRUNC && HAVE_PATHCONF && defined _PC_NAME_MAX
+  /* This implementation silently truncates pathname components.  If
+     the base names might be truncated, check whether the truncated
+     base names are the same, while checking the directories.  */
+  size_t slen_max = HAVE_LONG_FILE_NAMES ? 255 : _POSIX_NAME_MAX;
+  size_t min_baselen = MIN (source_baselen, dest_baselen);
+  if (slen_max <= min_baselen
+      && memcmp (source_basename, dest_basename, slen_max) == 0)
+    compare_dirs = true;
+#endif
 
-  if (source_baselen == dest_baselen
-      && memcmp (source_basename, dest_basename, dest_baselen) == 0)
+  if (compare_dirs)
     {
       struct stat source_dir_stats;
       struct stat dest_dir_stats;
@@ -80,12 +104,30 @@ same_name (const char *source, const char *dest)
 	  error (1, errno, "%s", dest_dirname);
 	}
 
+      same = SAME_INODE (source_dir_stats, dest_dir_stats);
+
+#if ! _POSIX_NO_TRUNC && HAVE_PATHCONF && defined _PC_NAME_MAX
+      if (same && ! identical_basenames)
+	{
+	  long name_max = (errno = 0, pathconf (dest_dirname, _PC_NAME_MAX));
+	  if (name_max < 0)
+	    {
+	      if (errno)
+		{
+		  /* Shouldn't happen.  */
+		  error (1, errno, "%s", dest_dirname);
+		}
+	      same = false;
+	    }
+	  else
+	    same = (name_max <= min_baselen
+		    && memcmp (source_basename, dest_basename, name_max) == 0);
+	}
+#endif
+
       free (source_dirname);
       free (dest_dirname);
-
-      if (SAME_INODE (source_dir_stats, dest_dir_stats))
-	return 1;
     }
 
-  return 0;
+  return same;
 }