[PATCH] gdi32: Accept 16-bit handles in get_dc_attr().

[Oleh Nykyforchyn]

I agree that to restore the missing upper part is better. Could You
submit the patch and mark my patch as superceded?

сб, 23 жовт. 2021 о 23:32 Nikolay Sivov <nsivov at codeweavers.com> пише:
>
> On 10/23/21 10:34 AM, Oleh Nykyforchyn wrote:
> > When background is erased in a 16 bit app, a handle to DC is passed
> > through USER16 functions, namely CallWindowProc16 (USER.122) and
> > DefDriverProc16 (USER.255), whose respective parameters are of type
> > WPARAM16, hence the upper part of the handle is cut. Later
> > the returned handle is rejected by get_dc_attr() in GDI32 because
> > its type is 0, although such handles are accepted by handle_entry().
> > This results in black and not cleared background.  Allowing type==0
> > in get_dc_attr() solves the problem.
> >
> > Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=51899
> > Signed-off-by: Oleh Nykyforchyn <oleh.nyk at gmail.com>
> > ---
> >  dlls/gdi32/dc.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/dlls/gdi32/dc.c b/dlls/gdi32/dc.c
> > index 1511c565194..a161b3cb640 100644
> > --- a/dlls/gdi32/dc.c
> > +++ b/dlls/gdi32/dc.c
> > @@ -56,7 +56,7 @@ DC_ATTR *get_dc_attr( HDC hdc )
> >  {
> >      DWORD type = gdi_handle_type( hdc );
> >      DC_ATTR *dc_attr;
> > -    if ((type & 0x1f0000) != NTGDI_OBJ_DC || !(dc_attr = get_gdi_client_ptr( hdc, 0 )))
> > +    if ((type && (type & 0x1f0000) != NTGDI_OBJ_DC) || !(dc_attr = get_gdi_client_ptr( hdc, 0 )))
> >      {
> >          SetLastError( ERROR_INVALID_HANDLE );
> >          return NULL;
> This doesn't look right, type mask shouldn't just disappear with no
> consequences. I think what has to happen is appropriate wow32 conversion
> in default procedure. It has to be applied for every affected message
> obviously. Please try attached patch.
>
>