Fixed disconnect before unsubscribe condition

receive.go

@@ -67,7 +67,7 @@ func (r *receiver) receive(readyCh chan struct{}, doneCh chan struct{}) {
 		r.durPublished = new(atomic.Int64)
 		r.bc = new(atomic.Int64)
 		r.start = time.Now()
-		r.allReceivedCh = make(chan struct{})
+		r.allReceivedCh = make(chan struct{}, 1)
 
 		token := cl.Subscribe(r.topic, byte(r.qos), r.msgHandler)
 		if token.Wait() && token.Error() != nil {
@@ -82,13 +82,13 @@ func (r *receiver) receive(readyCh chan struct{}, doneCh chan struct{}) {
 			readyCh <- struct{}{}
 		}
 
-		// wait for all messages to be received, then clean up and signal to the caller.
-		<-r.allReceivedCh
-
 		token = cl.Unsubscribe(r.topic)
 		if token.Wait() && token.Error() != nil {
 			log.Fatal(token.Error())
 		}
+
+		// wait for all messages to be received, then clean up and signal to the caller.
+		<-r.allReceivedCh
 	}
 }