ScrollWindow fix for windows with WS_CLIPCHILDREN style, with tests - version 2

[Alexandre Julliard]

Rein Klazes <wijn at wanadoo.nl> writes:

> windows		: scroll.c
> dlls/user/tests	: win.c
> 
> If ScrollWindowEx is called with SW_SCROLLCHILDREN flags for a window
> with a WS_CLIPCHILDREN style, then do not use the DCX_USESTYLE flag
> option to get a DC for this window. With a couple of regression tests.

DCX_USESTYLE has other effects, is it really correct to disable them
all?  And if so, wouldn't it be better to never use DCX_USESTYLE?

-- 
Alexandre Julliard
julliard at winehq.org