get autoconf-2.61+ working again

git-svn-id: https://urjtag.svn.sourceforge.net/svnroot/urjtag/trunk@1758 b68d4a1b-bc3d-0410-92ed-d4ac073336b7

urjtag/ChangeLog

@@ -1,3 +1,8 @@
+2010-02-03  Mike Frysinger  <vapier@gentoo.org>
+
+  * acinclude.m4 (AS_VAR_APPEND, m4_ifnblank): Provide fallback implementations
+    if autoconf is too old (<2.64).
+
 2010-02-02  Mike Frysinger  <vapier@gentoo.org>
 
   * src/tap/detect.c (urj_tap_detect_parts): Include bit/hex output in the

urjtag/acinclude.m4

@@ -130,3 +130,21 @@ AC_DEFUN([AC_PROG_SED],
 ])dnl
 
 
+dnl AS_VAR_APPEND
+dnl -------------
+dnl
+dnl this was added in autoconf-2.64+
+dnl
+m4_ifndef([AS_VAR_APPEND],[dnl
+AC_DEFUN([AS_VAR_APPEND], [${$1}="${$1}${$2}"])
+])dnl
+
+
+dnl m4_ifnblank
+dnl -----------
+dnl
+dnl this was added in autoconf-2.64+
+dnl
+m4_ifndef([m4_ifnblank],[dnl
+m4_define([m4_ifnblank], [m4_ifval(m4_normalize([$1]), [$2], [$3])])
+])dnl