Avoid integer overflow on exotic platforms.

[gnulib.git] / lib / xgetcwd.c

diff --git a/lib/xgetcwd.c b/lib/xgetcwd.c
index 95d0ab9..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
@@ -13,77 +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>
-#include "pathmax.h"
+#include "xgetcwd.h"
 
-#if HAVE_GETCWD
-char *getcwd ();
-#else
-char *getwd ();
-# define getcwd(Buf, Max) getwd (Buf)
-#endif
+#include <errno.h>
 
-extern void *xmalloc ();
-extern char *xstrdup ();
-extern void free ();
+#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 defined __GLIBC__ && __GLIBC__ >= 2
-  return getcwd (NULL, 0);
-#else
-  char *ret;
-  unsigned path_max;
-  char buf[1024];
-
-  errno = 0;
-  ret = getcwd (buf, sizeof (buf));
-  if (ret != NULL)
-    return xstrdup (buf);
-  if (errno != ERANGE)
-    return NULL;
-
-  path_max = 1300;
-  path_max += 2;               /* The getcwd docs say to do this. */
-
-  for (;;)
-    {
-      char *cwd = (char *) xmalloc (path_max);
-
-      errno = 0;
-      ret = getcwd (cwd, path_max);
-      if (ret != NULL)
-       return ret;
-      if (errno != ERANGE)
-       {
-         int save_errno = errno;
-         free (cwd);
-         errno = save_errno;
-         return NULL;
-       }
-
-      free (cwd);
-
-      path_max += path_max / 16;
-      path_max += 32;
-    }
-#endif
+  char *cwd = getcwd (NULL, 0);
+  if (! cwd && errno == ENOMEM)
+    xalloc_die ();
+  return cwd;
 }