From 68019ac41232673418550b0b4ff41e716096142e Mon Sep 17 00:00:00 2001
From: Marek Schimara <Marek.Schimara@bull.net>
Date: Wed, 22 Jun 2016 10:41:25 +0200
Subject: [PATCH] m4/acinclude.m4: fix for build error 'possibly undefined
 macro: AS_VAR_COPY'

        This happens with autoconf 2.63 or older (RHEL 6)
---
 m4/acinclude.m4 | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/m4/acinclude.m4 b/m4/acinclude.m4
index 78c2ccf9..4b7197c1 100644
--- a/m4/acinclude.m4
+++ b/m4/acinclude.m4
@@ -13,6 +13,15 @@ dnl EX_CHECK_ALL(library, function, header, pkgconf name, tested-version, homepa
 dnl              $1       $2        $3      $4            $5              $6        $7
 dnl
 dnl
+
+dnl
+dnl Fix for 'configure:31803: error: possibly undefined macro: AS_VAR_COPY'
+dnl     when building on RHEL 6 (autoconf 2.63)
+dnl     see https://github.com/gdnsd/gdnsd/issues/85
+m4_ifndef([AS_VAR_COPY],
+[m4_define([AS_VAR_COPY],
+[AS_LITERAL_IF([$1[]$2], [$1=$$2], [eval $1=\$$2])])])
+
 AC_DEFUN([EX_CHECK_ALL],
 [
  AC_LANG_PUSH(C)
-- 
2.47.2