[Bug 57160] New: 16-bit color no longer works when using Xephyr, regression caused by 05d727a93 Jul 11, 2024

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=57160

Bug ID: 57160
           Summary: 16-bit color no longer works when using Xephyr,
                    regression caused by 05d727a93 Jul 11, 2024
           Product: Wine
           Version: 9.13
          Hardware: x86
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: win32u
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

commit 05d727a935b9009f188cc74ca77e14afc44aef30 on July 11 for 9.13 caused a
regression where 16-bit color no longer displays correctly.  On the lastest git
master, notepad will just display black.  That checkin has 3 chunks of code, if
I comment out the larger chunk as seen below, git master will display notepad
correctly when using 16-bit color

// this is the new code that caused the regression

if (new_surface && !is_layered)
    {
        DWORD lwa_flags = 0;
        COLORREF key;
        BYTE alpha;

if (!NtUserGetLayeredWindowAttributes( hwnd, &key, &alpha, &lwa_flags
)) lwa_flags = 0;
        if (!(lwa_flags & LWA_ALPHA)) alpha = 255;
        if (!(lwa_flags & LWA_COLORKEY)) key = CLR_INVALID;
        window_surface_set_layered( new_surface, key, alpha << 24, 0 );
    }

command line used when testing:

Xephyr :1 -ac -screen 640x480x16 & DISPLAY=:1 wine-git/wine notepad

Tested On:
1) Debian 11 32-bit inside VMWare
2) Ubuntu 24 64-bit on Intel(R) Core(TM) i7-6700K