[Mediawiki-api] How to do 2 queries in one

Hi everyone. I'm building a Wikipedia bot. My bot finds out the timestamp and author of the current version of a page in one query, like this : http://en.wikipedia.org/w/api.php?action=query&prop=revisions&forma… If there is vandalism on the page, it attempts to find out the revid and name of the author of the previous author of the page, like this : http://en.wikipedia.org/w/api.php?action=query&prop=revisions&forma… If there is no other author other than the current author, then it will not give a result. Note that the previous author may be 1 or 10 revisions ago - it simply means the person who edited it most recently other than the current author. Now, is there a way for me to combine these queries into one? That is, can I get the present author of the page and the previous author in one call, knowing that the present author may be responsible for 1 or several revisions, and that there may be no previous author ? Richard