Regression in update region handling

[Maxime Bellengé]

Hello,

This patch introduced regressions :

Moved update region handling to the server
http://cvs.winehq.org/patch.py?id=14725

Since this patch has been applied, I have an application with acts like
a christmas tree :)
The application has owner drawn objects everywhere. What I see is that
every object is painted but once a first object is painted (button or
whatever) when the next one is painted all the rest of the dialog box is
erased and so on. So I can only see the last painted component although
every button is still usable.

This patch is a real nightmare to understand. I tried comparing traces
with +win before and after the patch but with no luck.

I would appreciate if someone can give me an hint on how to find this
bug.

thanks

Max