Merge pull request #274 from hannatao/master

bugfix #273: check connectack before create sub

Author: hannatao

mqtt/stream.go

@@ -47,17 +47,6 @@ func (c *Client) connect(obs Observer) (s *stream, err error) {
 		return nil, errors.Trace(err)
 	}
 
-	if len(c.ops.Subscriptions) != 0 {
-		subscribe := NewSubscribe()
-		subscribe.ID = subscribeId
-		subscribe.Subscriptions = c.ops.Subscriptions
-		err = conn.Send(subscribe, false)
-		if err != nil {
-			conn.Close()
-			return nil, errors.Trace(err)
-		}
-	}
-
 	s = &stream{
 		cli:             c,
 		observer:        obs,
@@ -76,6 +65,14 @@ func (c *Client) connect(obs Observer) (s *stream, err error) {
 		return nil, errors.Trace(err)
 	}
 	if len(c.ops.Subscriptions) != 0 {
+		subscribe := NewSubscribe()
+		subscribe.ID = subscribeId
+		subscribe.Subscriptions = c.ops.Subscriptions
+		err = conn.Send(subscribe, false)
+		if err != nil {
+			conn.Close()
+			return nil, errors.Trace(err)
+		}
 		err = s.subscribeFuture.Wait(c.ops.Timeout)
 		if err != nil {
 			s.die("subscribe timeout", err)