user32: add test cases for update rects affected by ShowWindow

[Dmitry Timoshkov]

"Clinton Stimpson" <cjstimpson at utwire.net> wrote:

> This patch adds a test to check the results of GetUpdateRect when a 
> child window is hidden.
> See bug #7360.  Wine incorrectly makes an update rect for the 
> grandparent window which has a todo_wine around it.
> 
> Thanks,
> Clinton Stimpson
> 
> ChangeLog:
>    Add test for GetUpdateRect and ShowWindow interaction.

After looking at this test once more, I think we need another test with
windows without CS_PARENTDC style set in order to understand better what
the proper behaviour is.

-- 
Dmitry.