winex11.drv: Make sure that default clipping region exists before calling ExcludeUpdateRgn().

[Alexandre Julliard]

Dmitry Timoshkov <dmitry at codeweavers.com> writes:

> I looks like the default clip region created by ExtSelectClipRgn() uses
> the dimensions of the selected bitmap, and it's not large enough.

That's a window DC, it doesn't have a selected bitmap.

-- 
Alexandre Julliard
julliard at winehq.org