I posted this answer to a question. The question was then edited by a roving well-wisher, which invalidated my answer. So I edited the question to reflect this, and deleted my answer.
The original question was subsequently restored, thus re-validating my answer. So I undeleted my answer. But when I went to revert the edit, my original answer was nowhere to be found! It seems that deleting and undeleting an answer clears its edit history.
Is this intentional, or a bug? Or is it just that retaining the edit history would be difficult to implement?