openat: test for fstatat (AT_FDCWD, ..., 0) bug

[gnulib.git] / lib / fstatat.c

diff --git a/lib/fstatat.c b/lib/fstatat.c
index d58e60b..f1bed73 100644 (file)
--- a/lib/fstatat.c
+++ b/lib/fstatat.c
@@ -1,6 +1,6 @@
 /* Work around an fstatat bug on Solaris 9.
 
-   Copyright (C) 2006, 2009 Free Software Foundation, Inc.
+   Copyright (C) 2006, 2009-2011 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
@@ -17,8 +17,25 @@
 
 /* Written by Paul Eggert and Jim Meyering.  */
 
+/* If the user's config.h happens to include <sys/stat.h>, let it include only
+   the system's <sys/stat.h> here, so that orig_fstatat doesn't recurse to
+   rpl_fstatat.  */
+#define __need_system_sys_stat_h
 #include <config.h>
 
+/* Get the original definition of fstatat.  It might be defined as a macro.  */
+#include <sys/types.h>
+#include <sys/stat.h>
+#undef __need_system_sys_stat_h
+
+#if HAVE_FSTATAT
+static inline int
+orig_fstatat (int fd, char const *filename, struct stat *buf, int flags)
+{
+  return fstatat (fd, filename, buf, flags);
+}
+#endif
+
 #include <sys/stat.h>
 
 #include <errno.h>
@@ -29,19 +46,33 @@
 
 # undef fstatat
 
+# ifndef FSTATAT_AT_FDCWD_0_BROKEN
+#  define FSTATAT_AT_FDCWD_0_BROKEN 0
+# endif
+
+# ifndef LSTAT_FOLLOWS_SLASHED_SYMLINK
+#  define LSTAT_FOLLOWS_SLASHED_SYMLINK 0
+# endif
+
 /* fstatat should always follow symbolic links that end in /, but on
    Solaris 9 it doesn't if AT_SYMLINK_NOFOLLOW is specified.
    Likewise, trailing slash on a non-directory should be an error.
    These are the same problems that lstat.c and stat.c address, so
-   solve it in a similar way.  */
+   solve it in a similar way.
+
+   AIX 7.1 fstatat (AT_FDCWD, ..., 0) always fails, which is a bug.
+   Work around this bug if FSTATAT_AT_FDCWD_0_BROKEN is nonzero.  */
 
 int
 rpl_fstatat (int fd, char const *file, struct stat *st, int flag)
 {
-  int result = fstatat (fd, file, st, flag);
+  int result =
+    (FSTATAT_AT_FDCWD_0_BROKEN && fd == AT_FDCWD && flag == 0
+     ? stat (file, st)
+     : orig_fstatat (fd, file, st, flag));
   size_t len;
 
-  if (result != 0)
+  if (LSTAT_FOLLOWS_SLASHED_SYMLINK || result != 0)
     return result;
   len = strlen (file);
   if (flag & AT_SYMLINK_NOFOLLOW)