do not subscribe closed clients

Author: Uladzimir Danko

lib/handlers/subscribe.js

@@ -155,6 +155,13 @@ function addSubs (sub, done) {
     func = blockDollarSignTopics(func)
   }
 
+  if (client.closed || client.broker.closed) {
+    // a hack, sometimes client.close() or broker.close() happened
+    // before authenticate() comes back
+    // we don't continue subscription here
+    return
+  }
+
   if (!client.subscriptions[topic]) {
     client.subscriptions[topic] = new Subscription(qos, func, rh, rap, nl)
     broker.subscribe(topic, func, done)