Ignore multiple join events for the same user

Because name changes are sent as join events as well and there seems to be no way to differentiate them from normal join events

src/matrix-rocketchat/handlers/events/room_handler.rs

@@ -131,13 +131,23 @@ impl<'a> RoomHandler<'a> {
 
     fn handle_user_join(&self, matrix_user_id: UserId, matrix_room_id: RoomId) -> Result<()> {
         let room = Room::find(self.connection, &matrix_room_id)?;
+
+        if UserInRoom::find_by_matrix_user_id_and_matrix_room_id(self.connection, &matrix_user_id, &matrix_room_id)?.is_some() {
+            let msg = format!("Skipping because the user {} is already in the room {} (join event triggered due to name change)",
+                              &matrix_user_id,
+                              &matrix_room_id);
+            debug!(self.logger, msg);
+            return Ok(());
+        }
+
         if room.is_admin_room {
             info!(self.logger, "Another user join the admin room {}, bot user is leaving", matrix_room_id);
             let admin_room_language = self.admin_room_language(&room)?;
             let body = t!(["errors", "other_user_joined"]).l(&admin_room_language);
             self.matrix_api.send_text_message_event(matrix_room_id, self.config.matrix_bot_user_id()?, body)?;
             self.leave_and_forget_room(&room)?;
         } else {
+            debug!(self.logger, format!("Adding user {} to room {}", &matrix_user_id, &matrix_room_id));
             let new_user_in_room = NewUserInRoom {
                 matrix_user_id: matrix_user_id,
                 matrix_room_id: matrix_room_id,

tests/admin_room.rs

@@ -457,3 +457,22 @@ fn ignore_messages_from_the_bot_user() {
     // no command is executed, so we get a timeout
     assert!(receiver.recv_timeout(default_timeout()).is_err());
 }
+
+#[test]
+fn ignore_multiple_join_events_for_the_same_user() {
+    let (message_forwarder, receiver) = MessageForwarder::new();
+    let mut matrix_router = Router::new();
+    matrix_router.put(SendMessageEventEndpoint::router_path(), message_forwarder, "send_message_event");
+
+    let test = Test::new().with_admin_room().with_matrix_routes(matrix_router).run();
+
+    helpers::join(&test.config.as_url,
+                  RoomId::try_from("!admin:localhost").unwrap(),
+                  UserId::try_from("@spec_user:localhost").unwrap());
+
+    // discard welcome message
+    receiver.recv_timeout(default_timeout()).unwrap();
+
+    // no message, because the join is ignored
+    assert!(receiver.recv_timeout(default_timeout()).is_err());
+}