[Bug 53979] New: d3d9:d3d9ex - test_wndproc() is sometimes missing a WM_WINDOWPOSCHANGING message in Wine

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=53979

Bug ID: 53979
           Summary: d3d9:d3d9ex - test_wndproc() is sometimes missing a
                    WM_WINDOWPOSCHANGING message in Wine
           Product: Wine
           Version: unspecified
          Hardware: x86-64
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: d3d
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

d3d9:d3d9ex - test_wndproc() is sometimes missing a WM_WINDOWPOSCHANGING
message in Wine:

d3d9ex.c:3115: Test failed: Expected message 0x46 for window 0x1, but didn't
receive it, i=1.

See https://test.winehq.org/data/patterns.html#d3d9:d3d9ex

This seems to be mostly happening on my desktop (Intel + KDE), but it also
happened on the debian11 VM in MR!1538 (unrelated heap refactoring). So it's
not specific to KDE and can indeed happen on the TestBot VMs.