windows are incompletely drawn: bisected to commit 7864ade5a8306c0078e16ae6d7e40bdece29395b

[Wolfgang Walter]

An application we use shows incompletely painted windows with 1.3.19. I 
bisected it to commit

7864ade5a8306c0078e16ae6d7e40bdece29395b is the first bad commit
commit 7864ade5a8306c0078e16ae6d7e40bdece29395b
Author: Dmitry Timoshkov 
Date:   Tue Sep 14 14:24:11 2010 +0900

winex11.drv: Avoid copying invalid window bits.

I reverted it in 1.3.19 and that fixed indeed the problem.

The wrongly painted windows are maximized windows within a MDI window: if 
there are serveral such windows opened and one switches between them parts of 
the newly active window is not painted and the content of the old one is 
still displayed.

Regards,