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

[Oleh Nykyforchyn]

I added a TRACE to dc.c:

---------
--- dc.c.prev   2021-10-21 13:47:33.567548593 +0300
+++ dc.c        2021-10-23 08:29:38.003977433 +0300
@@ -56,7 +56,15 @@
 {
     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 & 0x1f0000) != NTGDI_OBJ_DC)
+    {
+        TRACE("type %x, cut %x vs %x\n", type, type & 0x1f0000, NTGDI_OBJ_DC);
+        SetLastError( ERROR_INVALID_HANDLE );
+        return NULL;
+    }
+    else
+    if (!(dc_attr = get_gdi_client_ptr( hdc, 0 )))
     {
         SetLastError( ERROR_INVALID_HANDLE );
         return NULL;

-------

and there is still one rejected handle in a log for WinEdt.exe:

0104:trace:win:GetDCEx (00010072,010400B4,0x10088): returning 450100B0 (updated)
0104:trace:gdi:NtGdiCreateSolidBrush 808080
0104:trace:gdi:alloc_gdi_handle allocated NTGDI_OBJ_BRUSH 0xa1000a9 151/65536
0104:trace:gdi:create_brush 0xa1000a9
0104:trace:gdi:SelectObject (000000B0,0A1000A9)
0104:trace:gdi:get_dc_attr type 0, cut 0 vs 10000
0104:trace:gdi:get_dc_attr type 0, cut 0 vs 10000
0104:trace:win:BeginPaint hdc = 450100B0 box = ((0,0)-(1352,594)), fErase = 0
0104:trace:win:release_dc 00010072 450100B0

This one is due to parameters conversion in CallWindowProc16 (USER.122).

Shouldn't this function be patched as well?

нд, 24 жовт. 2021 о 09:50 Oleh Nykyforchyn <oleh.nyk at gmail.com> пише:
>
> 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 submit the patch and mark my patch as superceded?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.
> >
> >