Index: pbx/pbx_dundi.c
===================================================================
--- pbx/pbx_dundi.c	(revision 84633)
+++ pbx/pbx_dundi.c	(working copy)
@@ -578,11 +578,13 @@
 		} else {
 			/* No answers...  Find the fewest number of digits from the
 			   number for which we have no answer. */
-			char tmp[AST_MAX_EXTENSION];
+			char tmp[AST_MAX_EXTENSION + 1];
 			for (x=0;x<AST_MAX_EXTENSION;x++) {
 				tmp[x] = called_number[x];
 				if (!tmp[x])
 					break;
+
+				tmp[x + 1] = '\0';
 				if (!ast_canmatch_extension(NULL, map->lcontext, tmp, 1, NULL)) {
 					/* Oops found something we can't match.  If this is longer
 					   than the running hint, we have to consider it */