Avoid integer overflow on exotic platforms.

[gnulib.git] / lib / xgetcwd.c

diff --git a/lib/xgetcwd.c b/lib/xgetcwd.c
index 1409bcf..0f798da 100644 (file)
--- a/lib/xgetcwd.c
+++ b/lib/xgetcwd.c
@@ -1,5 +1,6 @@
 /* xgetcwd.c -- return current directory with unlimited length
-   Copyright (C) 1992, 1996, 2000, 2001 Free Software Foundation, Inc.
+
+   Copyright (C) 2001, 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
@@ -13,75 +14,30 @@
 
    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 David MacKenzie <djm@gnu.ai.mit.edu>.  */
+/* Written by Jim Meyering.  */
 
-#if HAVE_CONFIG_H
+#ifdef HAVE_CONFIG_H
 # include <config.h>
 #endif
 
-#include <stdio.h>
-#include <errno.h>
-#ifndef errno
-extern int errno;
-#endif
-
-#include <sys/types.h>
-
-#if HAVE_STDLIB_H
-# include <stdlib.h>
-#endif
-#if HAVE_UNISTD_H
-# include <unistd.h>
-#endif
+#include "xgetcwd.h"
 
-#if HAVE_GETCWD
-char *getcwd ();
-#else
-# include "pathmax.h"
-# define INITIAL_BUFFER_SIZE (PATH_MAX + 1)
-char *getwd ();
-# define getcwd(Buf, Max) getwd (Buf)
-#endif
+#include <errno.h>
 
+#include "getcwd.h"
 #include "xalloc.h"
 
-/* Return the current directory, newly allocated, arbitrarily long.
-   Return NULL and set errno on error. */
+/* Return the current directory, newly allocated.
+   Upon an out-of-memory error, call xalloc_die.
+   Upon any other type of error, return NULL.  */
 
 char *
-xgetcwd ()
+xgetcwd (void)
 {
-#if HAVE_GETCWD_NULL
   char *cwd = getcwd (NULL, 0);
   if (! cwd && errno == ENOMEM)
     xalloc_die ();
   return cwd;
-#else
-
-  /* The initial buffer size for the working directory.  A power of 2
-     detects arithmetic overflow earlier, but is not required.  */
-# ifndef INITIAL_BUFFER_SIZE
-#  define INITIAL_BUFFER_SIZE 128
-# endif
-
-  size_t buf_size = INITIAL_BUFFER_SIZE;
-
-  while (1)
-    {
-      char *buf = xmalloc (buf_size);
-      char *cwd = getcwd (buf, buf_size);
-      int saved_errno;
-      if (cwd)
-       return cwd;
-      saved_errno = errno;
-      free (buf);
-      if (saved_errno != ERANGE)
-       return NULL;
-      buf_size *= 2;
-      if (buf_size == 0)
-       xalloc_die ();
-    }
-#endif
 }