X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fsame.c;h=33e13a01b73c7a98e238b910505cb9327e202a31;hb=ec354b13bec21d8510dd60e1e129cc194809248b;hp=beb75c44edb078bf81a2ddac3c8a575379a7f1ce;hpb=81f3a79231bf3f35f4f4d12deec8b58586984ac8;p=gnulib.git

diff --git a/lib/same.c b/lib/same.c
index beb75c44e..33e13a01b 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 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
@@ -21,25 +23,22 @@
 # include <config.h>
 #endif
 
+#include <stdbool.h>
 #include <stdio.h>
 #ifdef HAVE_UNISTD_H
 # include <unistd.h>
 #endif
-#if HAVE_STDLIB_H
-# include <stdlib.h>
-#endif
+#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"
@@ -47,23 +46,7 @@ extern int errno;
 #include "error.h"
 #include "xalloc.h"
 
-#if ENABLE_NLS
-# include <libintl.h>
-# define _(Text) gettext (Text)
-#else
-# define _(Text) Text
-#endif
-
-#define STREQ(a, b) (strcmp ((a), (b)) == 0)
-
-#ifndef HAVE_DECL_FREE
-"this configure-time declaration test was not run"
-#endif
-#if !HAVE_DECL_FREE
-void free ();
-#endif
-
-char *base_name PARAMS ((char const *));
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
 
 #define SAME_INODE(Stat_buf_1, Stat_buf_2) \
   ((Stat_buf_1).st_ino == (Stat_buf_2).st_ino \
@@ -72,33 +55,77 @@ char *base_name PARAMS ((char const *));
 /* 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;
-
-  source_dirname = dir_name (source);
-  dest_dirname = dir_name (dest);
-  if (source_dirname == NULL || dest_dirname == NULL)
-    xalloc_die ();
+  /* Compare the basenames.  */
+  char const *source_basename = base_name (source);
+  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 (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);
-
-  return (SAME_INODE (source_dir_stats, dest_dir_stats)
-	  && STREQ (base_name (source), base_name (dest)));
+  return same;
 }