localename: Improvements for MacOS X and Cygwin.

[gnulib.git] / m4 / obstack-printf.m4

diff --git a/m4/obstack-printf.m4 b/m4/obstack-printf.m4
index 98860c2..969d620 100644 (file)
--- a/m4/obstack-printf.m4
+++ b/m4/obstack-printf.m4
@@ -1,4 +1,4 @@
-# obstack-printf.m4 serial 1
+# obstack-printf.m4 serial 2
 dnl Copyright (C) 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,
@@ -10,6 +10,9 @@ dnl obstack_vprintf behaves identically, so we only test for one.
 
 AC_DEFUN([gl_FUNC_OBSTACK_PRINTF],
 [
+  dnl Persuade glibc <stdio.h> to declare obstack_printf(), obstack_vprintf().
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+
   AC_REQUIRE([gl_STDIO_H_DEFAULTS])
   AC_CHECK_FUNCS_ONCE([obstack_printf])
   if test $ac_cv_func_obstack_printf = no ; then