Last modified: 2010-05-15 15:38:43 UTC
Note: actually, I'm talking about MediaWiki 1.5 beta 4 (used by the German Wikipedia) It's impossible to submit query parameters containing spaces to other sites (Google, for example) using InterWiki links, since those spaces are converted to underscores when the page is saved, even when you URL-encode them as "%20". I consider this a bug, not a feature, since MediaWiki accepts URLs containing spaces, it converts them to underscores itself when it received the request.
bug 707 needs tidying up (probably splitting) but it does cover exactly this problem. Glancing back, bug 707 comment 15 seems to summarise most of the issues. *** This bug has been marked as a duplicate of 707 ***