New module, file-set.

[gnulib.git] / lib / getcwd.c

diff --git a/lib/getcwd.c b/lib/getcwd.c
index ba22679..23b35de 100644 (file)
--- a/lib/getcwd.c
+++ b/lib/getcwd.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1991,92,93,94,95,96,97,98,99,2004,2005,2006 Free Software
+/* Copyright (C) 1991,92,93,94,95,96,97,98,99,2004,2005,2006,2007 Free Software
    Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -16,12 +16,10 @@
    with this program; if not, write to the Free Software Foundation,
    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
 
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
-
 #if !_LIBC
-# include "getcwd.h"
+# include <config.h>
+# include <unistd.h>
+# include "dirfd.h"
 #endif
 
 #include <errno.h>
@@ -36,25 +34,9 @@
 # define __set_errno(val) (errno = (val))
 #endif
 
-#if HAVE_DIRENT_H || _LIBC
-# include <dirent.h>
-# ifndef _D_EXACT_NAMLEN
-#  define _D_EXACT_NAMLEN(d) strlen ((d)->d_name)
-# endif
-#else
-# define dirent direct
-# if HAVE_SYS_NDIR_H
-#  include <sys/ndir.h>
-# endif
-# if HAVE_SYS_DIR_H
-#  include <sys/dir.h>
-# endif
-# if HAVE_NDIR_H
-#  include <ndir.h>
-# endif
-#endif
+#include <dirent.h>
 #ifndef _D_EXACT_NAMLEN
-# define _D_EXACT_NAMLEN(d) ((d)->d_namlen)
+# define _D_EXACT_NAMLEN(d) strlen ((d)->d_name)
 #endif
 #ifndef _D_ALLOC_NAMLEN
 # define _D_ALLOC_NAMLEN(d) (_D_EXACT_NAMLEN (d) + 1)
@@ -68,8 +50,6 @@
 # ifndef mempcpy
 #  define mempcpy __mempcpy
 # endif
-#else
-# include "mempcpy.h"
 #endif
 
 #include <limits.h>
@@ -116,6 +96,11 @@
 # define __opendir opendir
 # define __readdir readdir
 #endif
+
+/* The results of opendir() in this file are not used with dirfd and fchdir,
+   therefore save some unnecessary recursion in fchdir.c.  */
+#undef opendir
+#undef closedir
 \f
 /* Get the name of the current working directory, and put it in SIZE
    bytes of BUF.  Returns NULL if the directory couldn't be determined or
@@ -156,13 +141,18 @@ __getcwd (char *buf, size_t size)
   size_t allocated = size;
   size_t used;
 
-#if HAVE_PARTLY_WORKING_GETCWD && !defined AT_FDCWD
+#if HAVE_PARTLY_WORKING_GETCWD
   /* The system getcwd works, except it sometimes fails when it
      shouldn't, setting errno to ERANGE, ENAMETOOLONG, or ENOENT.  If
      AT_FDCWD is not defined, the algorithm below is O(N**2) and this
      is much slower than the system getcwd (at least on GNU/Linux).
      So trust the system getcwd's results unless they look
-     suspicious.  */
+     suspicious.
+
+     Use the system getcwd even if we have openat support, since the
+     system getcwd works even when a parent is unreadable, while the
+     openat-based approach does not.  */
+
 # undef getcwd
   dir = getcwd (buf, size);
   if (dir || (errno != ERANGE && !is_ENAMETOOLONG (errno) && errno != ENOENT))
@@ -245,6 +235,8 @@ __getcwd (char *buf, size_t size)
       dirstream = fdopendir (fd);
       if (dirstream == NULL)
        goto lose;
+      /* Reset fd.  It may have been closed by fdopendir.  */
+      fd = dirfd (dirstream);
       fd_needs_closing = false;
 #else
       dirstream = __opendir (dotlist);
@@ -399,7 +391,7 @@ __getcwd (char *buf, size_t size)
   used = dir + allocated - dirp;
   memmove (dir, dirp, used);
 
-  if (buf == NULL && size == 0)
+  if (size == 0)
     /* Ensure that the buffer is only as large as necessary.  */
     buf = realloc (dir, used);