Wikimedia Bugzilla is closed!

with bug 6332 a new variable was introduced, mainpage-description. unfortunately, this is inconsistent with other variables (portal, portal-url, etc.). I suggest correcting this to mainpage as description and mainpage-url as qualified page name.

In order to do this in every Messages*.php a line 'mainpage-url'      => $mainpage, has to be added

Moreover, in Title::newMainPage:
-               $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
+               $title = Title::newFromText( wfMsgForContent( 'mainpage-url' ) );