Merge 405da00 into ea036d7

nats.go

@@ -3932,7 +3932,8 @@ func (jsi *jsSub) trackSequences(msg *Msg) {
 
 // NextMsg will return the next message available to a synchronous subscriber
 // or block until one is available. An error is returned if the subscription is invalid (ErrBadSubscription),
-// the connection is closed (ErrConnectionClosed), or the timeout is reached (ErrTimeout).
+// the connection is closed (ErrConnectionClosed), the timeout is reached (ErrTimeout),
+// or if there were no responders (ErrNoResponders) when used in the context of a request/reply.
 func (s *Subscription) NextMsg(timeout time.Duration) (*Msg, error) {
 	if s == nil {
 		return nil, ErrBadSubscription
@@ -4053,6 +4054,9 @@ func (s *Subscription) processNextMsgDelivered(msg *Msg) error {
 			nc.mu.Unlock()
 		}
 	}
+	if len(msg.Data) == 0 && msg.Header.Get(statusHdr) == noResponders {
+		return ErrNoResponders
+	}
 
 	return nil
 }

test/basic_test.go

@@ -623,6 +623,20 @@ func TestBasicNoRespondersSupport(t *testing.T) {
 	if m, err := nc.RequestWithContext(ctx, "foo", nil); err != nats.ErrNoResponders {
 		t.Fatalf("Expected a no responders error and nil msg, got m:%+v and err: %v", m, err)
 	}
+
+	// SubscribeSync
+	inbox := nats.NewInbox()
+	sub, err := nc.SubscribeSync(inbox)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = nc.PublishRequest("foo", inbox, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if m, err := sub.NextMsg(2 * time.Second); err != nats.ErrNoResponders {
+		t.Fatalf("Expected a no responders error and nil msg, got m:%+v and err: %v", m, err)
+	}
 }
 
 func TestOldRequest(t *testing.T) {