[Bug 57813] New: EnumDesktopWindows does not SetLastError when NtUserBuildHwndList fails

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=57813

Bug ID: 57813
           Summary: EnumDesktopWindows does not SetLastError when
                    NtUserBuildHwndList fails
           Product: Wine
           Version: 9.22
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: user32
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Hello,

Since Wine 9.22 (commit
https://gitlab.winehq.org/wine/wine/-/commit/7d5a43b60492d8b7f49a6b4a574f28a...
"user32: Reimplement the enum window functions using NtUserBuildHwndList()."),
EnumDesktopWindows can fail without setting the Last Error. More precisely, the
function returns FALSE and GetLastError() does not return the associated error.

I guess that's cause by line 76
(https://gitlab.winehq.org/wine/wine/-/blob/7d5a43b60492d8b7f49a6b4a574f28a52...
):

status = NtUserBuildHwndList( 0, hwnd, FALSE, TRUE, 0, size, list, &size );
    /* ... */
    if (status != STATUS_BUFFER_TOO_SMALL) return FALSE;

A call to SetLastError (or set_ntstatus(status)) seems to be missing.

(By the way, Microsoft documents EnumDesktopWindows in
https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-enumd...
"If the function fails or is unable to perform the enumeration, the return
value is zero. To get extended error information, call GetLastError.")

This issue seems to affect other functions in the same file
(dlls/user32/win.c): when a "NTSTATUS status" is used to get the return value
of functions NtUser..., several functions return FALSE or NULL without setting
the Last Error.

Context:

I first saw this on Arch Linux running Wine 9.22 and successfully reproduced
the issue on a clean Ubuntu 24.04 installation with Wine 10.1 installed by
following instructions from
https://gitlab.winehq.org/wine/wine/-/wikis/Debian-Ubuntu .

I am testing this using a program I wrote many years ago,
https://github.com/fishilico/shared/blob/361bd98566a4da881d746a95804723d0d0e...
. Before Wine 9.22, it successfully enumerated the Stations and Desktops. Since
Wine 9.22, the callback of EnumDesktopWindows is no longer called and
EnumDesktopWindows returns FALSE with GetLastError() showing the previous error
(if SetLastError(0) is added before the call to EnumDesktopWindows,
GetLastError() returns 0 after the call).

In case it is useful, here is an extract of "WINEDEBUG=trace+all wine
./list_desktops.exe" :

20129.073:01e4:01e8:Call
user32.EnumDesktopWindows(00000068,1400016a0,7ffffe2ffe50) ret=140001b17
    20129.073:01e4:01e8:trace:heap:RtlAllocateHeap handle 00007FFFFE320000,
flags 0, size 0x400, return 00007FFFFE380EC0, status 0.
    20129.074:01e4:01e8:trace:heap:RtlFreeHeap handle 00007FFFFE320000, flags
0, ptr 00007FFFFE380EC0, return 1, status 0.
    20129.074:01e4:01e8:Ret  user32.EnumDesktopWindows() retval=00000000
ret=140001b17
    20129.074:01e4:01e8:Call KERNEL32.GetLastError() ret=140001b1f
    20129.074:01e4:01e8:Ret  KERNEL32.GetLastError() retval=00000000
ret=140001b1f

By the way, debugging with winedbg shows that NtUserBuildHwndList returns
0xC0000022 (STATUS_ACCESS_DENIED). I don't know why (and what I should do to
make it work as before), but the bug I am reporting is not about this.