inforce arg checking

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@15176 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/mod/applications/mod_valet_parking/mod_valet_parking.c

@@ -137,6 +137,11 @@ SWITCH_STANDARD_APP(valet_parking_function)
 			const char *max = argv[4];
 			int min_i, max_i, id, in = -1;
 
+			if (argc < 5) {
+				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Usage: %s\n", VALET_APP_SYNTAX);
+				return;
+			}
+
 			if (io) {
 				if (!strcasecmp(io, "in")) {
 					in = 1;