-#serial 1000
-
-dnl From Paul Eggert
-dnl Check for a working mktime.
-dnl This is a preview of what should appear in the next public autoconf release.
-
-dnl Override any existing definition.
-undefine([AC_FUNC_MKTIME])
-
-AC_DEFUN(AC_FUNC_MKTIME,
+# mktime.m4 serial 4
+dnl Copyright (C) 2002, 2003 Free Software Foundation, Inc.
+dnl This file is free software, distributed under the terms of the GNU
+dnl General Public License. As a special exception to the GNU General
+dnl Public License, this file may be distributed as part of a program
+dnl that contains a configuration script generated by Autoconf, under
+dnl the same distribution terms as the rest of that program.
+
+dnl From Jim Meyering.
+
+# Redefine AC_FUNC_MKTIME, to fix a bug in Autoconf 2.57 and earlier.
+# This redefinition can be removed once a new version of Autoconf comes out.
+# The redefinition is taken from
+# <http://savannah.gnu.org/cgi-bin/viewcvs/*checkout*/autoconf/autoconf/lib/autoconf/functions.m4?rev=1.78>.
+# AC_FUNC_MKTIME
+# --------------
+AC_DEFUN([AC_FUNC_MKTIME],