Short description I sometimes find myself wanting to search all the versions of a page (e.g. I want to see at what point some text was added). Presuably, if I do not have access to some versions of a page, those versions would be excluded from my search. I'm envisioning a search box on the get info page "Search all versions of this page" or something like that.
Xapian search has history search. As of 1.8.1 it is still a bit buggy, but we are working on fixing it.