user32: Avoid querying the server to determine whether the desktop window is a child window.

[Huw Davies]

On Wed, Feb 01, 2017 at 05:46:46PM +0100, Alexandre Julliard wrote:
> Huw Davies <huw at codeweavers.com> writes:
> 
> > Signed-off-by: Huw Davies <huw at codeweavers.com>
> > ---
> >  dlls/user32/win.c | 31 +++++++++++++++++++++++++++++--
> >  1 file changed, 29 insertions(+), 2 deletions(-)
> >
> > diff --git a/dlls/user32/win.c b/dlls/user32/win.c
> > index a7be4a3..341769f 100644
> > --- a/dlls/user32/win.c
> > +++ b/dlls/user32/win.c
> > @@ -414,6 +414,33 @@ static HWND *list_window_parents( HWND hwnd )
> >      return NULL;
> >  }
> >  
> > +/*******************************************************************
> > + *		is_child_win
> > + *
> > + * Helper to determine whether WS_CHILD is set.
> > + * It avoids a server round trip for the desktop window.
> > + */
> 
> We could probably make GetWindowLong return hardcoded values for the
> desktop window, so that all callers benefit.

Good plan.  It's made slightly more complicated by the message window,
but I've sent a patch that does that.

Huw.