* lib/openat.h (rpl_fstatat): New macro, if

[HAVE_OPENAT && ! LSTAT_FOLLOWS_SLASHED_SYMLINK.
(fstatat): Define to rpl_fstatat under the same conditions,
unless COMPILING_FSTATAT.
* m4/openat.m4 (gl_FUNC_OPENAT): Compile fstatat.c too, if fstatat
seems to have the bug.
* lib/fstatat.c: New file.
* modules/openat (Files): Add it.

diff --git a/ChangeLog b/ChangeLog
index 6c3b89c..e7ec6a6 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2006-11-20  Paul Eggert  <eggert@cs.ucla.edu>
+
+       * lib/openat.h (rpl_fstatat): New macro, if
+       [HAVE_OPENAT && ! LSTAT_FOLLOWS_SLASHED_SYMLINK.
+       (fstatat): Define to rpl_fstatat under the same conditions,
+       unless COMPILING_FSTATAT.
+       * m4/openat.m4 (gl_FUNC_OPENAT): Compile fstatat.c too, if fstatat
+       seems to have the bug.
+       * lib/fstatat.c: New file.
+       * modules/openat (Files): Add it.
+
 2006-11-20  Bruno Haible  <bruno@clisp.org>
 
        * Makefile: New file.

diff --git a/lib/fstatat.c b/lib/fstatat.c
new file mode 100644 (file)
index 0000000..92a5164
--- /dev/null
+++ b/lib/fstatat.c
@@ -0,0 +1,57 @@
+/* Work around an fstatat bug on Solaris 9.
+
+   Copyright (C) 2006 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
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Paul Eggert and Jim Meyering.  */
+
+#include <config.h>
+
+#define COMPILING_FSTATAT 1
+#include "openat.h"
+
+#include <errno.h>
+#include <string.h>
+
+/* fstatat should always follow symbolic links that end in /, but on
+   Solaris 9 it doesn't if AT_SYMLINK_NOFOLLOW is specified.  This is
+   the same problem that lstat.c addresses, so solve it in a similar
+   way.  */
+
+int
+rpl_fstatat (int fd, char const *file, struct stat *st, int flag)
+{
+  int result = fstatat (fd, file, st, flag);
+
+  if (result == 0 && (flag & AT_SYMLINK_NOFOLLOW) && S_ISLNK (st->st_mode)
+      && file[strlen (file) - 1] == '/')
+    {
+      /* FILE refers to a symbolic link and the name ends with a slash.
+        Get info about the link's referent.  */
+      result = fstatat (fd, file, st, flag & ~AT_SYMLINK_NOFOLLOW);
+      if (result == 0 && ! S_ISDIR (st->st_mode))
+       {
+         /* fstatat succeeded and FILE references a non-directory.
+            But it was specified via a name including a trailing
+            slash.  Fail with errno set to ENOTDIR to indicate the
+            contradiction.  */
+         errno = ENOTDIR;
+         return -1;
+       }
+    }
+
+  return result;
+}

diff --git a/lib/openat.h b/lib/openat.h
index 9eca973..f8333f0 100644 (file)
--- a/lib/openat.h
+++ b/lib/openat.h
@@ -85,6 +85,14 @@ bool openat_needs_fchdir (void);
 
 #endif
 
+#if HAVE_OPENAT && ! LSTAT_FOLLOWS_SLASHED_SYMLINK
+int rpl_fstatat (int fd, char const *file, struct stat *st, int flag);
+# if !COMPILING_FSTATAT
+#  undef fstatat
+#  define fstatat rpl_fstatat
+# endif
+#endif
+
 int mkdirat (int fd, char const *file, mode_t mode);
 void openat_restore_fail (int) ATTRIBUTE_NORETURN;
 void openat_save_fail (int) ATTRIBUTE_NORETURN;

diff --git a/m4/openat.m4 b/m4/openat.m4
index fca3bd0..4789482 100644 (file)
--- a/m4/openat.m4
+++ b/m4/openat.m4
@@ -20,8 +20,9 @@ AC_DEFUN([gl_FUNC_OPENAT],
   AC_CHECK_FUNCS_ONCE([lchmod])
   AC_CHECK_FUNCS_ONCE([fdopendir])
   AC_REPLACE_FUNCS(openat)
-  case $ac_cv_func_openat in
-  yes) ;;
+  case $ac_cv_func_openat+$ac_cv_func_lstat_dereferences_slashed_symlink in
+  yes+yes) ;;
+  yes+*) AC_LIBOBJ([fstatat]);;
   *)
     AC_DEFINE([__OPENAT_PREFIX], [[rpl_]],
       [Define to rpl_ if the openat replacement function should be used.])

diff --git a/modules/openat b/modules/openat
index c14e731..7754a3d 100644 (file)
--- a/modules/openat
+++ b/modules/openat
@@ -4,6 +4,7 @@ Open a file at a directory.
 Files:
 lib/at-func.c
 lib/fchmodat.c
+lib/fstatat.c
 lib/mkdirat.c
 lib/openat.c
 lib/openat.h