3.3.1.1 dup: reset dup when route message

apps/emqtt/src/emqtt_router.erl

@@ -65,7 +65,7 @@ start_link() ->
     gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
 
 route(Message) ->
-	emqtt_pubsub:publish(retained(Message)).
+	emqtt_pubsub:publish(retained(reset_dup(Message))).
 
 %% ------------------------------------------------------------------
 %% gen_server Function Definitions
@@ -97,3 +97,6 @@ retained(Msg = #mqtt_message{retain = true, topic = Topic}) ->
 
 retained(Msg) -> Msg.
 
+reset_dup(Msg = #mqtt_message{dup = true}) -> Msg#mqtt_message{dup = false};
+reset_dup(Msg) -> Msg.
+