user32: Fix error handling in {Begin,End,}DeferWindowPos() to match Windows behavior (resend)

[Nikolay Sivov]

On 25.08.2015 16:08, Rodrigo Rivas wrote:
> I sent this on July 15th, but it went through the cracks. Maybe the
> mail text was not detailed enough, so I will try and explain it better
> this time.
>
> The error behaviour of functions BeginDeferWindowPos(),
> DeferWindowPos() and EndDeferWindowPos() in Wine is different than in
> Windows.
>
> In Windows, when DeferWindowPos() is used with an invalid HWND, this
> function fails, but the eventual EndDeferWindowPos() will succeed and
> move all the other windows in the set.
> In Wine, however, DeferWindowPos() does not check the HWND, so it
> never fails. But then, it fails in EndDeferWindowPos(), moving only
> the windows passed before the invalid HWND and leaving the windows
> after the invalid HWND unmoved.
>
> The Windows behaviour is consistent in every version I tested (XP and 7).
>
> The attached patch makes the Wine error behaviour the same as the Windows one.
> It also considers the case where the HWND is valid when calling
> DeferWindowPos() but is destroyed before calling EndDeferWindowPos():
> The error is simply ignored.
>
> It fixes bug #23187.
>
> ---
>   dlls/user32/tests/Makefile.in |   1 +
>   dlls/user32/tests/defer.c     | 168 ++++++++++++++++++++++++++++++++++++++++++
>   dlls/user32/winpos.c          |  14 ++--
>   3 files changed, 178 insertions(+), 5 deletions(-)
>   create mode 100644 dlls/user32/tests/defer.c
>

I don't think you need a new file for that, how about moving this to win.c?

Regarding fix itself, it's probably better to split it to two - fix 
DeferWindowPos() in first + related tests, and End* one in the second.