--- a/ChangeLog	Sun Sep 28 16:17:51 2008 +0200
+++ b/ChangeLog	Sun Sep 28 16:19:57 2008 +0200
@@ -1,5 +1,12 @@
 2008-09-28  Bruno Haible  <bruno@clisp.org>
 
+	Override open more carefully.
+	* lib/open.c (orig_open): New function.
+	(rpl_open): Use orig_open instead of open.
+	* lib/fcntl.in.h: Add special invocation convention.
+	* m4/open.m4 (gl_PREREQ_OPEN): New macro.
+	(gl_FUNC_OPEN): Invoke it.
+
 	Override freopen more carefully.
 	* lib/freopen.c (orig_freopen): New function.
 	(rpl_freopen): Use orig_freopen instead of freopen.

--- a/lib/fcntl.in.h	Sun Sep 28 16:17:51 2008 +0200
+++ b/lib/fcntl.in.h	Sun Sep 28 16:19:57 2008 +0200
@@ -17,9 +17,20 @@
 
 /* written by Paul Eggert */
 
-#ifndef _GL_FCNTL_H
+@PRAGMA_SYSTEM_HEADER@
+
+#if defined __need_system_fcntl_h
+/* Special invocation convention.  */
 
-@PRAGMA_SYSTEM_HEADER@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#@INCLUDE_NEXT@ @NEXT_FCNTL_H@
+
+#else
+/* Normal invocation convention.  */
+
+#ifndef _GL_FCNTL_H
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -121,3 +132,4 @@
 
 #endif /* _GL_FCNTL_H */
 #endif /* _GL_FCNTL_H */
+#endif

--- a/lib/open.c	Sun Sep 28 16:17:51 2008 +0200
+++ b/lib/open.c	Sun Sep 28 16:19:57 2008 +0200
@@ -18,6 +18,18 @@
 
 #include <config.h>
 
+/* Get the original definition of open.  It might be defined as a macro.  */
+#define __need_system_fcntl_h
+#include <fcntl.h>
+#undef __need_system_fcntl_h
+#include <sys/types.h>
+
+static inline int
+orig_open (const char *filename, int flags, mode_t mode)
+{
+  return open (filename, flags, mode);
+}
+
 /* Specification.  */
 #include <fcntl.h>
 
@@ -32,7 +44,6 @@
 
 int
 open (const char *filename, int flags, ...)
-# undef open
 {
   mode_t mode;
   int fd;
@@ -91,7 +102,7 @@
     }
 # endif
 
-  fd = open (filename, flags, mode);
+  fd = orig_open (filename, flags, mode);
 
 # if OPEN_TRAILING_SLASH_BUG
   /* If the filename ends in a slash and fd does not refer to a directory,

--- a/m4/open.m4	Sun Sep 28 16:17:51 2008 +0200
+++ b/m4/open.m4	Sun Sep 28 16:19:57 2008 +0200
@@ -1,4 +1,4 @@
-# open.m4 serial 2
+# open.m4 serial 3
 dnl Copyright (C) 2007-2008 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -45,8 +45,15 @@
             [Define to 1 if open() fails to recognize a trailing slash.])
           REPLACE_OPEN=1
           AC_LIBOBJ([open])
+          gl_PREREQ_OPEN
           ;;
       esac
       ;;
   esac
 ])
+
+# Prerequisites of lib/open.c.
+AC_DEFUN([gl_PREREQ_OPEN],
+[
+  AC_REQUIRE([AC_C_INLINE])
+])