Ensure to not be able to call s9y files under circumstances where .htaccess does not deny request AND register_globals is turned on

include/functions_permalinks.inc.php

@@ -2,6 +2,10 @@
 # Copyright (c) 2003-2005, Jannis Hermanns (on behalf the Serendipity Developer Team)
 # All rights reserved.  See LICENSE file for licensing details
 
+if (IN_serendipity !== true) {
+    die ("Don't hack!");
+}
+
 if (defined('S9Y_FRAMEWORK_PERMALINKS')) {
     return;
 }