X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fsame.c;h=1abc55c88058b8266537145629f87d26d35ba6e6;hb=afc6cbe4fe4892c5ee4166cab87fede6f294a27d;hp=0e2807ac200d86e1a8daed8265ebc45fcc2ff62f;hpb=de4cde2dc3121bf766cb9827da38411377ece979;p=gnulib.git

diff --git a/lib/same.c b/lib/same.c
index 0e2807ac2..1abc55c88 100644
--- a/lib/same.c
+++ b/lib/same.c
@@ -1,10 +1,11 @@
 /* Determine whether two file names refer to the same file.
-   Copyright (C) 1997-2000 Free Software Foundation, Inc.
 
-   This program is free software; you can redistribute it and/or modify
+   Copyright (C) 1997-2000, 2002-2006, 2009-2010 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
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -12,96 +13,111 @@
    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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 /* written by Jim Meyering */
 
-#if HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include <config.h>
 
+#include <stdbool.h>
 #include <stdio.h>
-#ifdef HAVE_UNISTD_H
-# include <unistd.h>
-#endif
-#if HAVE_STDLIB_H
-# include <stdlib.h>
-#endif
+#include <unistd.h>
+#include <stdlib.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <ctype.h>
 #include <errno.h>
-#ifndef errno
-extern int errno;
-#endif
 
-#if HAVE_STRING_H
-# include <string.h>
-#else
-# include <strings.h>
+#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"
-
-#if ENABLE_NLS
-# include <libintl.h>
-# define _(Text) gettext (Text)
-#else
-# define _(Text) Text
-#endif
+#include "same-inode.h"
 
-#ifndef HAVE_DECL_FREE
-"this configure-time declaration test was not run"
-#endif
-#if !HAVE_DECL_FREE
-void free ();
+#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)
-
 /* 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)
 {
-  struct stat source_dir_stats;
-  struct stat dest_dir_stats;
-  char *source_dirname, *dest_dirname;
-  char *source_basename, *dest_basename;
-  size_t source_baselen, dest_baselen;
-
-  source_dirname = dir_name (source);
-  dest_dirname = dir_name (dest);
+  /* Compare the basenames.  */
+  char const *source_basename = last_component (source);
+  char const *dest_basename = last_component (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 components of file names.  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 (stat (source_dirname, &source_dir_stats))
+  if (compare_dirs)
     {
-      /* Shouldn't happen.  */
-      error (1, errno, "%s", source_dirname);
-    }
+      struct stat source_dir_stats;
+      struct stat dest_dir_stats;
+      char *source_dirname, *dest_dirname;
+
+      /* Compare the parent directories (via the device and inode numbers).  */
+      source_dirname = dir_name (source);
+      dest_dirname = dir_name (dest);
+
+      if (stat (source_dirname, &source_dir_stats))
+        {
+          /* Shouldn't happen.  */
+          error (1, errno, "%s", source_dirname);
+        }
+
+      if (stat (dest_dirname, &dest_dir_stats))
+        {
+          /* Shouldn't happen.  */
+          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
 
-  if (stat (dest_dirname, &dest_dir_stats))
-    {
-      /* Shouldn't happen.  */
-      error (1, errno, "%s", dest_dirname);
+      free (source_dirname);
+      free (dest_dirname);
     }
 
-  free (source_dirname);
-  free (dest_dirname);
-
-  if (! SAME_INODE (source_dir_stats, dest_dir_stats))
-    return 0;
-
-  source_basename = base_name (source);
-  dest_basename = base_name (dest);
-  source_baselen = base_len (source_basename);
-  dest_baselen = base_len (dest_basename);
-  return (source_baselen == dest_baselen
-	  && memcmp (source_basename, dest_basename, dest_baselen) == 0);
+  return same;
 }