# HG changeset patch
# User Eric Blake <eblake@redhat.com>
# Date 1389028859 25200
# Node ID b1b3e9794cf9757b7a744dd2bc2520f7781e66e7
# Parent  386365d65046c9b947f81f28344880b19647db1e
include_next: port to autoconf 2.63

On RHEL 6.4 (using autoconf 2.63), './gnulib-tool --test math'
fails with the following, since commit 74540d44:
executing autoconf
configure:5693: error: possibly undefined macro: AS_VAR_COPY
      If this token and others are legitimate, please use m4_pattern_allow.
      See the Autoconf documentation.

Since we document that we support out-of-the-box use with autoconf
2.59 and later, the fix is to provide a fallback definition.

* m4/gnulib-common.m4 (AS_VAR_COPY): Define if missing.

Signed-off-by: Eric Blake <eblake@redhat.com>

diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2014-01-06  Eric Blake  <eblake@redhat.com>
+
+	include_next: port to autoconf 2.63
+	* m4/gnulib-common.m4 (AS_VAR_COPY): Define if missing.
+
 2014-01-04  Jim Meyering  <meyering@fb.com>
 
 	maint: add a gnulib-local rule to keep non-ascii out of .texi files
diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4
--- a/m4/gnulib-common.m4
+++ b/m4/gnulib-common.m4
@@ -1,4 +1,4 @@
-# gnulib-common.m4 serial 33
+# gnulib-common.m4 serial 34
 dnl Copyright (C) 2007-2014 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -375,3 +375,7 @@
   AC_CACHE_VAL([$1], [$2])
   as_echo_n="$saved_as_echo_n"
 ])
+
+# AS_VAR_COPY was added in autoconf 2.63b
+m4_define_default([AS_VAR_COPY],
+[AS_LITERAL_IF([$1[]$2], [$1=$$2], [eval $1=\$$2])])