-#serial 1000
-
-dnl Just like mktime.m4 from automake-1.3b, but with an additional test.
-dnl Renamed to have jm_ prefix and to use jm_ prefix on cache variable names.
-
-AC_DEFUN(jm_AM_FUNC_MKTIME,
-[AC_REQUIRE([AC_HEADER_TIME])dnl
- AC_CHECK_HEADERS(sys/time.h unistd.h)
- AC_CHECK_FUNCS(alarm)
- AC_CACHE_CHECK([for working mktime], jm_am_cv_func_working_mktime,
- [AC_TRY_RUN(
-changequote(<<, >>)dnl
-<</* Test program from Paul Eggert (eggert@twinsun.com)
- and Tony Leneis (tony@plaza.ds.adp.com). */
-#if TIME_WITH_SYS_TIME
-# include <sys/time.h>
-# include <time.h>
-#else
-# if HAVE_SYS_TIME_H
-# include <sys/time.h>
-# else
-# include <time.h>
-# endif
-#endif
-
-#if HAVE_UNISTD_H
+#serial 13
+dnl Copyright (C) 2002, 2003, 2005, 2006, 2007 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Jim Meyering.
+
+# Redefine AC_FUNC_MKTIME, to fix a bug in Autoconf 2.61a and earlier.
+# This redefinition can be removed once a new version of Autoconf is assumed.
+# The redefinition is taken from
+# <http://cvs.sv.gnu.org/viewcvs/*checkout*/autoconf/autoconf/lib/autoconf/functions.m4?rev=1.119>.
+# AC_FUNC_MKTIME
+# --------------
+AC_DEFUN([AC_FUNC_MKTIME],
+[AC_CHECK_HEADERS_ONCE(unistd.h)
+AC_CHECK_FUNCS_ONCE(alarm)
+AC_CACHE_CHECK([for working mktime], ac_cv_func_working_mktime,
+[AC_RUN_IFELSE([AC_LANG_SOURCE(
+[[/* Test program from Paul Eggert and Tony Leneis. */
+#include <limits.h>
+#include <stdlib.h>
+#include <time.h>
+
+#ifdef HAVE_UNISTD_H