Fix two possible crashes, one only in 1.6.1 and one in 1.6.1 forward.

(closes issue #15739)
 Reported by: DLNoah, jeffg
 Patches: 
       20090914__issue15739.diff.txt uploaded by tilghman (license 14)
       20090922__issue15739.diff.txt uploaded by tilghman (license 14)
 Tested by: DLNoah, jeffg


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@219987 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_directory.c

@@ -525,6 +525,11 @@ static int search_directory_sub(const char *context, struct ast_config *vmcfg, s
 		strsep(&bufptr, ",");
 		pos = strsep(&bufptr, ",");
 
+		/* No name to compare against */
+		if (ast_strlen_zero(pos)) {
+			continue;
+		}
+
 		res = 0;
 		if (ast_test_flag(&flags, OPT_LISTBYLASTNAME)) {
 			res = check_match(&item, context, pos, v->name, ext, 0 /* use_first_name */);