From 2305b66555d8812eb26002b51b5ee1f4a1a5186a Mon Sep 17 00:00:00 2001
From: Bruno Haible <bruno@clisp.org>
Date: Sun, 6 Feb 2011 22:12:25 +0100
Subject: [PATCH] iswblank: Ensure declaration on glibc systems.

* m4/iswblank.m4 (gl_FUNC_ISWBLANK): Require gl_USE_SYSTEM_EXTENSIONS.
* modules/iswblank (Dependencies): Add 'extensions'.
* doc/posix-functions/iswblank.texi: Document the glibc problem.
---
 ChangeLog                         | 7 +++++++
 doc/posix-functions/iswblank.texi | 3 +++
 m4/iswblank.m4                    | 4 +++-
 modules/iswblank                  | 1 +
 4 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 6266eaa6f6..6fed235d54 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2011-02-06  Bruno Haible  <bruno@clisp.org>
+
+	iswblank: Ensure declaration on glibc systems.
+	* m4/iswblank.m4 (gl_FUNC_ISWBLANK): Require gl_USE_SYSTEM_EXTENSIONS.
+	* modules/iswblank (Dependencies): Add 'extensions'.
+	* doc/posix-functions/iswblank.texi: Document the glibc problem.
+
 2011-02-06  Bruno Haible  <bruno@clisp.org>
 
 	New module 'iswblank'.
diff --git a/doc/posix-functions/iswblank.texi b/doc/posix-functions/iswblank.texi
index 367a5e2fe3..b36e69fc08 100644
--- a/doc/posix-functions/iswblank.texi
+++ b/doc/posix-functions/iswblank.texi
@@ -15,6 +15,9 @@ AIX 4.3.2, IRIX 6.5, OSF/1 5.1, Solaris 9, mingw.
 This function is declared but not defined on some platforms:
 IRIX 6.5.30.
 @item
+This function is not declared (without @code{-D_GNU_SOURCE}) on some platforms:
+glibc 2.8.
+@item
 This function returns 0 for all possible arguments on some platforms:
 Linux libc5.
 @end itemize
diff --git a/m4/iswblank.m4 b/m4/iswblank.m4
index 8f15f40e45..38641ffb66 100644
--- a/m4/iswblank.m4
+++ b/m4/iswblank.m4
@@ -1,4 +1,4 @@
-# iswblank.m4 serial 1
+# iswblank.m4 serial 2
 dnl Copyright (C) 2011 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -8,6 +8,8 @@ AC_DEFUN([gl_FUNC_ISWBLANK],
 [
   AC_REQUIRE([gl_WCTYPE_H_DEFAULTS])
   AC_REQUIRE([gl_WCTYPE_H])
+  dnl Persuade glibc <wctype.h> to declare iswblank().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
   AC_CHECK_FUNCS_ONCE([iswblank])
   AC_CHECK_DECLS_ONCE([iswblank])
   if test $ac_cv_func_iswblank = no; then
diff --git a/modules/iswblank b/modules/iswblank
index 2a4a817319..972107eb21 100644
--- a/modules/iswblank
+++ b/modules/iswblank
@@ -7,6 +7,7 @@ m4/iswblank.m4
 
 Depends-on:
 wctype-h
+extensions
 
 configure.ac:
 gl_FUNC_ISWBLANK
-- 
2.30.2