Also (via bawolff):
http://incubator.wikimedia.org/wiki/?uselang=cs
should now go to Main page/cs and not to Hlavní strana

So I suppose Title::newMainPage() should be somehow tweaked the way it will allow it.

What I understand is wanted:

*The mainpage message to be a UI message instead of a content message.
*But not to use any of the translations provided for it (by mediawiki), since we only want it to work for Main Pages that actually exist, so we only want translations that we manually make.

The proposed solution
*Make a new global variable to control which message we use for the 'mainpage' system message. Since a wiki could change it to some non-existent message with no automatic translations, it would only work for manual translations as desired.

This seems ugly in the extreme. What happens if another system message needs to be special handled like that. I really don't like this solution, it just seems "wrong".

If we must do something like this, perhaps a new global similar to $wgForceUIMsgAsContentMsg but causes the message to only take manually made edits to the mediawiki namespace into account when the content language does not equal the user language - aka if there is no manual made edits in the mediawiki namespace for the userlanguage, then treated the same as a normal content language message. (Is that even possible in the current message system).

*Sigh*, as an ugly hack, I should mention that the following would do what you want (but is ugly ugly).

Make mainpage _not_ be in $wgForceUIMsgAsContentMsg

make the content of mediawiki:Mainpage be {{int:new-mainpage}}

Then the main page will be the value of the new-mainpage message (either the specific translation for the language [ aka mediawiki:new-mainpage/fr ] or if that doesn't exist the generic one).

saibotrash wrote:

I just had to create those two redirs: https://commons.wikimedia.org/w/index.php?title=%D8%AF%DB%95%D8%B3%D8%AA%D9%BE%DB%8E%DA%A9&oldid=67738834 and https://commons.wikimedia.org/w/index.php?title=Destp%C3%AAk&oldid=67738751 Without the redir the links to the mainpage (logo and menu) had pointed to a dead page for /ku and /ku-arab

That's what happen when adding messages to $wgForceUIMsgAsContentMsg. You may need to create pages for the content too many times.

For the OP problem, just make logo use mainpage-url?