Index: m4/mbchar.m4
===================================================================
RCS file: /cvsroot/gnulib/gnulib/m4/mbchar.m4,v
retrieving revision 1.2
diff -u -r1.2 mbchar.m4
--- m4/mbchar.m4	26 Sep 2005 13:58:51 -0000	1.2
+++ m4/mbchar.m4	28 Jul 2006 05:47:10 -0000
@@ -10,6 +10,7 @@
 AC_DEFUN([gl_MBCHAR],
 [
   AC_REQUIRE([AC_GNU_SOURCE])
+  AC_CHECK_FUNCS([iswcntrl])
   dnl The following line is that so the user can test
   dnl HAVE_WCHAR_H && HAVE_WCTYPE_H before #include "mbchar.h".
   AC_CHECK_HEADERS_ONCE(wchar.h wctype.h)
Index: lib/mbchar.h
===================================================================
RCS file: /cvsroot/gnulib/gnulib/lib/mbchar.h,v
retrieving revision 1.3
diff -u -r1.3 mbchar.h
--- lib/mbchar.h	28 Jun 2006 13:11:03 -0000	1.3
+++ lib/mbchar.h	28 Jul 2006 05:47:10 -0000
@@ -176,6 +176,10 @@
 
 typedef struct mbchar mbchar_t;
 
+#if !defined iswcntrl && !HAVE_ISWCNTRL
+# define iswcntrl(wc) 0
+#endif
+
 /* Access the current character.  */
 #define mb_ptr(mbc) ((mbc).ptr)
 #define mb_len(mbc) ((mbc).bytes)