preparation for expand-before-require warning

[Eric Blake]

Autoconf itself has some bugs where we expand a macro, then later require it, 
from within the same defun'd body.  Since I've just documented that this can 
lead to out-of-order expansion, and since I will soon be making this issue a 
syntax warning, we ought to set the proper example.  This patch fixes one 
instance of it, as well as a quoting bug I noticed in m4sh.  There are a couple 
more problems in m4sh itself (for example, _AS_SHELL_SANITIZE expands 
_AS_PATH_SEPARATOR_PREPARE then requires it via _AS_PATH_WALK), but I'm still 
trying to come up with the cleanest fixes for those.

From: Eric Blake <address@hidden>
Date: Tue, 20 Jan 2009 10:08:11 -0700
Subject: [PATCH] Clean up some bugs caught by preliminary dependency validation.

* lib/autoconf/headers.m4 (AC_DIR_HEADER): Don't invoke
AC_HEADER_DIRENT, since AC_FUNC_CLOSEDIR_VOID requires it.
* lib/m4sugar/m4sh.m4 (_AS_DETECT_BETTER_SHELL)
(_AS_SHELL_SANITIZE): Fix quoting bugs.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog               |    8 ++++++++
 lib/autoconf/headers.m4 |   15 +++++++--------
 lib/m4sugar/m4sh.m4     |    4 ++--
 3 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 7029b84..6023598 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2009-01-20  Eric Blake  <address@hidden>
+
+       Clean up some bugs caught by preliminary dependency validation.
+       * lib/autoconf/headers.m4 (AC_DIR_HEADER): Don't invoke
+       AC_HEADER_DIRENT, since AC_FUNC_CLOSEDIR_VOID requires it.
+       * lib/m4sugar/m4sh.m4 (_AS_DETECT_BETTER_SHELL)
+       (_AS_SHELL_SANITIZE): Fix quoting bugs.
+
 2009-01-19  Eric Blake  <address@hidden>
 
        Improve AC_REQUIRE documentation.
diff --git a/lib/autoconf/headers.m4 b/lib/autoconf/headers.m4
index 0bf4f60..47468f0 100644
--- a/lib/autoconf/headers.m4
+++ b/lib/autoconf/headers.m4
@@ -1,8 +1,8 @@
 # This file is part of Autoconf.                       -*- Autoconf -*-
 # Checking for headers.
 #
-# Copyright (C) 1988, 1999, 2000, 2001, 2002, 2003, 2004, 2006, 2008
-# Free Software Foundation, Inc.
+# Copyright (C) 1988, 1999, 2000, 2001, 2002, 2003, 2004, 2006, 2008,
+# 2009 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
@@ -887,8 +887,7 @@ use HAVE_STRING_H and HAVE_MEMORY_H, not NEED_MEMORY_H.])
 # defines a different set of C preprocessor macros to indicate which
 # header file is found.
 AU_DEFUN([AC_DIR_HEADER],
-[AC_HEADER_DIRENT
-AC_FUNC_CLOSEDIR_VOID
+[AC_FUNC_CLOSEDIR_VOID
 test ac_cv_header_dirent_dirent_h &&
   AC_DEFINE([DIRENT], 1, [Same as `HAVE_DIRENT_H', don't depend on me.])
 test ac_cv_header_dirent_sys_ndir_h &&
diff --git a/lib/m4sugar/m4sh.m4 b/lib/m4sugar/m4sh.m4
index 0c4c37f..2e17a9d 100644
--- a/lib/m4sugar/m4sh.m4
+++ b/lib/m4sugar/m4sh.m4
@@ -217,7 +217,7 @@ m4_define([_AS_DETECT_SUGGESTED_PRUNE],
 m4_defun([_AS_DETECT_BETTER_SHELL],
 dnl Remove any tests from suggested that are also required
 [m4_set_map([_AS_DETECT_SUGGESTED_BODY], [_AS_DETECT_SUGGESTED_PRUNE])]dnl
-[m4_pushdef([AS_EXIT], [exit m4_default([$1], 1)])]dnl
+[m4_pushdef([AS_EXIT], [exit m4_default(]m4_dquote([$][1])[, 1)])]dnl
 [if test "x$CONFIG_SHELL" = x; then
   as_bourne_compatible="AS_ESCAPE(_m4_expand([_AS_BOURNE_COMPATIBLE]))"
   _AS_DETECT_EXPAND([as_required], [_AS_DETECT_REQUIRED_BODY])
@@ -429,7 +429,7 @@ test x$exitcode = x0[]])# _AS_SHELL_FN_WORK
 # it is executed prior to shell function definitions, hence the
 # temporary redefinition of AS_EXIT.
 m4_defun([_AS_SHELL_SANITIZE],
-[m4_pushdef([AS_EXIT], [exit m4_default([$1], 1)])]dnl
+[m4_pushdef([AS_EXIT], [exit m4_default(]m4_dquote([$][1])[, 1)])]dnl
 [m4_text_box([M4sh Initialization.])
 
 AS_BOURNE_COMPATIBLE
-- 
1.6.0.4