No need any more to check for setlocale - all systems have it.

ChangeLog

@@ -1,3 +1,8 @@
+2006-10-17  Paul Eggert  <eggert@cs.ucla.edu>
+
+	* lib/localcharset.c: Do not check HAVE_SETLOCALE.
+	* m4/localcharset.m4 (gl_LOCALCHARSET): Don't check for setlocale.
+
 2006-10-17  Eric Blake  <ebb9@byu.net>
 
 	* lib/sigprocmask.c (sigprocmask): Fix typo.

lib/localcharset.c

@@ -41,7 +41,7 @@
 # if HAVE_LANGINFO_CODESET
 #  include <langinfo.h>
 # else
-#  if HAVE_SETLOCALE
+#  if 0 /* see comment below */
 #   include <locale.h>
 #  endif
 # endif
@@ -351,7 +351,7 @@ locale_charset (void)
      (like SunOS 4 or DJGPP) have only the C locale.  Therefore we don't
      use setlocale here; it would return "C" when it doesn't support the
      locale name the user has set.  */
-#  if HAVE_SETLOCALE && 0
+#  if 0
   locale = setlocale (LC_CTYPE, NULL);
 #  endif
   if (locale == NULL || locale[0] == '\0')

m4/localcharset.m4

@@ -1,4 +1,4 @@
-# localcharset.m4 serial 4
+# localcharset.m4 serial 5
 dnl Copyright (C) 2002, 2004, 2006 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -9,7 +9,6 @@ AC_DEFUN([gl_LOCALCHARSET],
   dnl Prerequisites of lib/localcharset.c.
   AC_REQUIRE([AM_LANGINFO_CODESET])
   AC_CHECK_DECLS_ONCE(getc_unlocked)
-  AC_CHECK_FUNCS_ONCE(setlocale)
 
   dnl Prerequisites of the lib/Makefile.am snippet.
   AC_REQUIRE([AC_CANONICAL_HOST])