Hello. I verified the fix for bug 542 (Link text shouldn't be duplicated in title attributes) with MediaWiki 1.17 which was deployed to jawp (Japanese Wikipedia) on Feb 16th, 2011. It almost works fine, BUT doesn't in case of stub link.
If I set a number, e.g. 10000, to the "Threshold for stub link" field in the "My preferences" page, stub links are created if the page size is smaller than 10000 bytes. In this case, tooltip still appear even if the link text is equal to the target page name. I doubt this is a bug. Could someone check this out?