Fix circular dependency error with autoconf 2.6.3.

Signed-off-by: Andreas Schneider <anschneider@suse.de>
(cherry picked from commit 26e82e3e006a80c9d4d1cb437eb39b02efa7c3ad)

diff --git a/source/lib/replace/autoconf-2.60.m4 b/source/lib/replace/autoconf-2.60.m4
index acdcd38efe6165aebc8ef1cb2322044c7594e2f2..2d5dbc16610a3b6107e69d6a699a68db4530a61c 100644 (file)
--- a/source/lib/replace/autoconf-2.60.m4
+++ b/source/lib/replace/autoconf-2.60.m4
@@ -179,6 +179,7 @@ AC_DEFUN([AC_PROG_CC_C99],
 # ------------------------
 # Enable extensions on systems that normally disable them,
 # typically due to standards-conformance issues.
+m4_ifndef([AC_USE_SYSTEM_EXTENSIONS],[
 AC_DEFUN([AC_USE_SYSTEM_EXTENSIONS],
 [
   AC_BEFORE([$0], [AC_COMPILE_IFELSE])
@@ -208,3 +209,4 @@ AC_DEFUN([AC_USE_SYSTEM_EXTENSIONS],
     AC_DEFINE([__EXTENSIONS__])
   AC_DEFINE([_POSIX_PTHREAD_SEMANTICS])
 ])
+])