async fn compute_join_state_changes(
services: &Services,
sender_user: &UserId,
room_id: &RoomId,
full_state: bool,
state_after: StateAfter,
since_shortstatehash: Option<ShortStateHash>,
horizon_shortstatehash: Option<ShortStateHash>,
after_shortstatehash: Option<ShortStateHash>,
current_shortstatehash: Option<ShortStateHash>,
joined_since_last_sync: bool,
witness: Option<&Witness>,
) -> Result<StateChanges>