[Bug 51313] New: gdi32:driver sometimes fails with a STATUS_GRAPHICS_PRESENT_OCCLUDED error

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=51313

Bug ID: 51313
           Summary: gdi32:driver sometimes fails with a
                    STATUS_GRAPHICS_PRESENT_OCCLUDED error
           Product: Wine
           Version: 6.10
          Hardware: x86-64
                OS: Windows
            Status: NEW
          Severity: normal
          Priority: P2
         Component: gdi32
          Assignee: [e-mail]
          Reporter: [e-mail]

gdi32:driver sometimes gets one or two failures like these:

https://test.winehq.org/data/patterns.html#gdi32:driver

driver.c:649: Test failed: Got unexpected return code 0xc01e0006.
driver.c:689: Test failed: Got unexpected return code 0xc01e0006.

0xc01e0006 is STATUS_GRAPHICS_PRESENT_OCCLUDED. This has happened before but
the reason for this error was not identified:

https://www.winehq.org/pipermail/wine-devel/2019-July/148494.html

I initially suspected a leftover window from a previous test, specifically an
Internet Explorer first-run dialog. However the screenshots in the TestBot jobs
show that this happens even when there is no such dialog (or at least the
dialog is gone by the time the tests complete).

The failures always happen on the same two lines despite the occlusion status
being checked in other places. Also both failures happen right after minimizing
the windows. So it seems likely there is a race condition, either in the test
or in the underlying API (if so it spans Windows 10 1607 to 2009).