[Bug 50495] New: the WS_EX_LAYERED set SetWindowLong GWL_EXSTYLE , Window show white rather than transparency.

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=50495

Bug ID: 50495
           Summary: the WS_EX_LAYERED set SetWindowLong GWL_EXSTYLE ,
                    Window show white rather than transparency.
           Product: WineHQ Bugzilla
           Version: unspecified
          Hardware: x86
                OS: Linux
            Status: UNCONFIRMED
          Severity: major
          Priority: P2
         Component: bugzilla-unknown
          Assignee: [e-mail]
          Reporter: [e-mail]
                CC: [e-mail]
      Distribution: ---

Created attachment 69150
  --> https://bugs.winehq.org/attachment.cgi?id=69150
This program will create a transparent full screen window.

When I use the following code to create a transparent full screen window.

```

HWND hWnd;
    hWnd =  CreateWindowEx(WS_EX_APPWINDOW, "WindowClass", "Demo", WS_VISIBLE|
WS_MAXIMIZE, CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);
    SetWindowLong(hWnd, GWL_STYLE, GetWindowLong(hWnd, GWL_STYLE) &
(~WS_DLGFRAME));
    RECT rect;
    GetWindowRect(hWnd, &rect);
    SetWindowPos(hWnd, HWND_TOPMOST, rect.left, rect.top, rect.right -
rect.left, rect.bottom - rect.top, SWP_DRAWFRAME);
    LONG ret = GetWindowLong(hWnd, GWL_EXSTYLE);
        ret = ret | WS_EX_LAYERED;
        SetWindowLong(hWnd, GWL_EXSTYLE, ret);
    ShowWindow(hWnd, SW_SHOWMAXIMIZED);
    UpdateWindow(hWnd); 
```

In Windows this program display window is a full screen transparent window，But
running this little program with Wine on Linux displays a full-screen white
window.

This problem occurred. I tried to modify the SetWindowLong API function
implementation, but it didn't change much. I hope the bosses can help me.