[Bug 23187] DeferWindowPos behaves wrong when invalid HWND

https://bugs.winehq.org/show_bug.cgi?id=23187

--- Comment #7 from Rodrigo  ---
Created attachment 51713
  --> https://bugs.winehq.org/attachment.cgi?id=51713
patch that fixes the bug

Ok, I've finally written the patch. If think this is not the place and want me
to sent it to [e-mail], please, say so.

I've also checked the case in which the window is valid when calling
DeferWindowPos() but it is destroyed before EndDeferWindowPos(). MSWin just
ignores this error, so my patch does the same.

The patch itself is quite easy, but the test case... I don't know if it fits.
Feel free to change whatever needs to be changed.