Fixed another flapping test...

server/server_redelivery_test.go

@@ -707,23 +707,30 @@ func TestPersistentStoreAckMsgRedeliveredToDifferentQueueSub(t *testing.T) {
 	s := runServerWithOpts(t, opts, nil)
 	defer shutdownRestartedServerOnTestExit(&s)
 
-	var err error
-	var sub2 stan.Subscription
+	var (
+		err    error
+		sub2   stan.Subscription
+		sub2Mu sync.Mutex
+	)
 
 	errs := make(chan error, 10)
 	sub2Recv := make(chan bool)
 	redelivered := int32(0)
 	trackDelivered := int32(0)
 	cb := func(m *stan.Msg) {
 		if m.Redelivered {
-			if m.Sub != sub2 {
-				errs <- fmt.Errorf("Expected redelivered msg to be sent to sub2")
-				return
-			}
 			if atomic.AddInt32(&redelivered, 1) != 1 {
 				errs <- fmt.Errorf("Message redelivered after restart")
 				return
 			}
+			sub2Mu.Lock()
+			isSub2 := m.Sub == sub2
+			sub2Mu.Unlock()
+			if !isSub2 {
+				// We want the message to be redelivered to sub2, so wait
+				// for that to happen
+				return
+			}
 			sub2Recv <- true
 		} else {
 			if atomic.LoadInt32(&trackDelivered) == 1 {
@@ -740,21 +747,25 @@ func TestPersistentStoreAckMsgRedeliveredToDifferentQueueSub(t *testing.T) {
 
 	// Create a queue subscriber with manual ackMode that will
 	// not ack the message.
-	if _, err := sc.QueueSubscribe("foo", "g1", cb, stan.AckWait(ackWaitInMs(15)),
+	if _, err := sc.QueueSubscribe("foo", "g1", cb, stan.AckWait(ackWaitInMs(100)),
 		stan.SetManualAckMode()); err != nil {
 		t.Fatalf("Unexpected error on subscribe: %v", err)
 	}
+	waitForNumSubs(t, s, clientName, 1)
+	// Send a message that we know is going to go to the first (and only)
+	// queue sub that will not ack this message
+	if err := sc.Publish("foo", []byte("msg")); err != nil {
+		t.Fatalf("Unexpected error on publish: %v", err)
+	}
+	sub2Mu.Lock()
 	// Create this subscriber that will receive and ack the message
-	sub2, err = sc.QueueSubscribe("foo", "g1", cb, stan.AckWait(ackWaitInMs(15)))
+	sub2, err = sc.QueueSubscribe("foo", "g1", cb)
+	sub2Mu.Unlock()
 	if err != nil {
 		t.Fatalf("Unexpected error on subscribe: %v", err)
 	}
 	// Make sure these are registered.
 	waitForNumSubs(t, s, clientName, 2)
-	// Send a message
-	if err := sc.Publish("foo", []byte("msg")); err != nil {
-		t.Fatalf("Unexpected error on publish: %v", err)
-	}
 	// Wait for sub2 to receive the message.
 	select {
 	case <-sub2Recv: