Deliver pubsub notifications to remote servers for nodes with presence based delivery

Nodes configured for presence based delivery did send notifications
only to subscribers that did match presence rules. But this only
works for local users, as we don't know presence for remote users.

This change makes subscribers from remote server get
notification without performing any presence tests.

Author: prefiks

src/mod_pubsub.erl

@@ -2702,21 +2702,26 @@ sub_option_can_deliver(_, _, _) -> true.
 presence_can_deliver(_, false) ->
     true;
 presence_can_deliver({User, Server, Resource}, true) ->
-    case ejabberd_sm:get_user_present_resources(User, Server) of
-	[] ->
-	    false;
-	Ss ->
-	    lists:foldl(fun
-		    (_, true) ->
-			true;
-		    ({_, R}, _Acc) ->
-		    	case Resource of
-			    <<>> -> true;
-			    R -> true;
-			    _ -> false
-			end
-		end,
-		false, Ss)
+    case ejabberd_router:is_my_route(Server) of
+	% We don't know presence of users on remote server, so always deliver
+	false -> true;
+	_ ->
+	    case ejabberd_sm:get_user_present_resources(User, Server) of
+		[] ->
+		    false;
+		Ss ->
+		    lists:foldl(fun
+				    (_, true) ->
+					true;
+				    ({_, R}, _Acc) ->
+					case Resource of
+					    <<>> -> true;
+					    R -> true;
+					    _ -> false
+					end
+				end,
+				false, Ss)
+	    end
     end.
 
 -spec state_can_deliver(ljid(), subOptions()) -> [ljid()].