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: wine-bugs@winehq.org Reporter: nicolas.iooss.2010_wine@m4x.org 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.