Most likely not correct, as it breaks comctl32:buttonv6 tests
https://reactos.org/testman/compare.php?ids=68146,68147
But greatly eliminates perceived flickering when hovering
with the mouse about buttons in unthemed mode.
We suffered from these regressions for years and nobody did
find a proper solution, therefore it's time to at least workaround them.
The patch did not expose any new real-world-issues after I retested
the whole rapps suite against it in 0.4.12RCs.
I committed the same workaround already into 0.4.12-RC-30-g
9513c9bf12
CORE-13278 was once introduced/unhidden by SVN 73806 ==
c607de714c
CORE-16093 was once introduced/unhidden by SVN 74149 ==
301c476074