Last modified: 2006-07-28 03:17:08 UTC
The above url gives the current revision instead of the ancient revision referred to by the oldid parameter. This seems somewhat aberrant (and confuses my script no end).
I think it's not related to MediaWiki but to a broken database in English Wikipedia – see http://mail.wikipedia.org/pipermail/wikitech-l/2006-July/037111.html .
I am dubious about this explanation. After all, the url http://en.wikipedia.org/w/index.php?title=MediaWiki:Monobook.css&oldid=3933070 retrieves the old revision fine; it's just that it doesn't do so with action=raw. Ancientness of the revision is not the issue - this seems to affect every old revision in the MediaWiki namespace.
Moreover, the same bug appears in my local mediawiki installation, so I think we can rule out the database problems.
Created attachment 2131 [details] One-line patch I think this little patch fixes things.
Added in SVN trunk r15863.