Redmine

Now in Attachment model is

after_destroy :delete_from_disk

If you want to construct a serious logic with Rollback this behaviour leads to remove file from disk, but leave an attachment record in DB.
In my project I replaced this callback on

after_commit :delete_from_disk, on: :destroy

and it works perfect.

I think this is a good modification for Redmine. It have full backward compatibility but can extend ability for strong logic in app.