Events core.delete_user_before and core.delete_user_after compact the wrong vars

For both core.delete_user_before and core.delete_user_after (file includes/functions_user.php), the following vars are compacted:

$vars = array('mode', 'user_id', 'post_username');

However, $user_id and $post_username do not exist in both of the contexts. This makes the events unusable.