user32:clipboard CLIPBRDWNDCLASS interference (Radeon, others)

[Zebediah Figura]

On 6/1/21 6:58 PM, Francois Gouget wrote:
> 
> This is the Windows side of the issue.
> 
> user32:clipboard sometimes fails like this:
> 
> clipboard.c:54: 0cc8: Starting open_and_empty_clipboard_thread hWnd=00010010
> clipboard.c:55: 0cc8: OpenClipboard(00010010) = 1 (open=00010010 own=00000000)
> # the thread terminates which implicitly calls CloseClipboard()
> # so the clipboard should be unopened
> 
> clipboard.c:429: Test failed: wrong open window 00670304
> # but it is actually opened
> 
> It turns out 670304 is actually a CLIPBRDWNDCLASS window created by
> RadeonSettings.exe.
> 
> CLIPBRDWNDCLASS is (usually) a class registered by ole32.
> 
> Why does a graphics driver (or associated tools) need to access the
> clipboard? It may actually be some background thing done by the QT5
> framework in which case (based on the issue below) upgrading to a driver
> using QT5 > 5.12 may help.
> 
> https://github.com/Sigil-Ebook/Sigil/issues/401
> https://code.qt.io/cgit/qt/qtbase.git/tree/src/plugins/platforms/windows/qwindowsclipboard.cpp
> 
> 
> But it turns out Radeon is not the only one using Ole's clipboard and if
> I try enough times I can also get failures on Nvidia. The w7u VM also
> has the telltale class but I have not seen failures there.
> 
> cw-rx460-win81 (Radeon 19.11.3)
> clipboard.c:2248: 00670304 CLIPBRDWNDCLASS 0190 '' [C:\Program Files\AMD\CNext\CNext\RadeonSettings.exe]
>                    hwnd     class           pid  text executable path
> 
> cw-rx460-win2009 (Radeon 21.3.2)
> clipboard.c:2246: 00040054 CLIPBRDWNDCLASS 0c1c '' [C:\Windows\explorer.exe]
> clipboard.c:2246: 0004002C CLIPBRDWNDCLASS 1850 '' [C:\Windows\System32\svchost.exe]
> clipboard.c:2246: 00030056 CLIPBRDWNDCLASS 1850 '' [C:\Windows\System32\svchost.exe]
> 
> cw-gtx460-win2009 (Game Ready Driver 391.35)
> clipboard.c:2247: 000201B2 CLIPBRDWNDCLASS 1c68 '' [C:\Windows\System32\svchost.exe]
> clipboard.c:2247: 00010230 CLIPBRDWNDCLASS 1c68 '' [C:\Windows\System32\svchost.exe]
> 
> w7u
> clipboard.c:2246: 000100EA CLIPBRDWNDCLASS 05f0 '' [C:\Windows\Explorer.EXE]
> clipboard.c:2246: 00010052 CLIPBRDWNDCLASS 05f0 '' [C:\Windows\Explorer.EXE]
> 
> 
> In any case, guided by the failure patterns I first tried to upgrade the
> Radeon driver. That helped on cw-rx460-1909 (21.3.2) but the latest
> drivers either won't install on older Windows versions (the infamous
> error 184), or crash regularly (even when left alone, and frequently
> enough during the tests to trigger a Windows reboot). So at least
> Windows 10 1507 and Windows 8.1 are stuck with 19.11.3 and its
> RadeonSettings.exe (I did not try the intermediate Windows versions).
> 
> Furthermore, while it would likely greatly reduce the failure rate we'd
> probably still get failures once in a while, likely at a rate so low it
> would cause TestBot false positives. Just like on Nvidia actually (see
> the cw-gtx560-1809-32 and cw-gtx560-1909-32 lines).
> 


Or it's those "helpful" overlay/settings windows that always appear on 
startup. Maybe it's possible to just disable the service?