Validate disconnect before submitting; some tests will fail

Author: Bret Ambrose

lib/browser/mqtt5.ts

@@ -21,6 +21,7 @@ import {CrtError} from "./error";
 import * as ws from "./ws";
 import * as mqtt_shared from "../common/mqtt_shared";
 import * as auth from "./auth";
+import * as validate from "./mqtt_internal/validate";
 
 export * from "../common/mqtt5";
 export * from '../common/mqtt5_packet';
@@ -373,6 +374,12 @@ export class Mqtt5Client extends BufferedEventEmitter implements mqtt5.IMqtt5Cli
      * @param disconnectPacket (optional) properties of a DISCONNECT packet to send as part of the shutdown process
      */
     stop(disconnectPacket?: mqtt5_packet.DisconnectPacket) {
+        // maintain backwards comaptibility with previous implementation which let validation errors
+        // trump the stop request
+        if (disconnectPacket) {
+            validate.validateInitialOutboundPacket(disconnectPacket, internal_mqtt_client.ProtocolMode.Mqtt5);
+        }
+
         this.internalClient.stop(disconnectPacket);
     }