I've only seen one instance of this, but it seems like something that
really shouldn't happen, so I thought I'd report it.
On [[en:Talk:Politics of Japan]], an anon had blanked the page a while
back with nobody noticing; yesterday I noticed and hit "rollback".
Instead of my rollback adding a new revision after the anon's, it seems
like it actually *deleted* the anon's revision from the article
history... so it looks like I'm making a null-edit, with an edit summary
claiming to be reverting a non-existent edit. The page-blanking edit is
still listed in the user's edit history though
([[en:Special:Contributions/198.169.169.32]]), so the article and user
edit histories are now inconsistent.
-Mark