http://bugs.winehq.org/show_bug.cgi?id=19773
--- Comment #4 from Stefan Dösinger stefandoesinger@gmx.at 2009-10-07 08:43:51 --- Wow, that is an old regression.
I think it is somewhat strange that enabling the scissor test(which reduces the area that is cleared) blacks out the screen. A more common situation is that we're clearing too much, thus the screen gets black.
I can imagine two scenarios:
1) We're supposed to clear more than we're clearing, and the depth buffer contains values that breaks further drawing
2) The scissor test doesn't get disabled properly.
I think (2) is unlikely. You can try that by adding a glDisable(GL_SCISSOR_TEST) after the clearing is done.
(1) Can be tested by porting the clear tests from dlls/d3d9/tests/visual.c to dlls/d3d8/tests/visual.c, and checking if the outcome is the same. Maybe d3d8 clears are not limited to the viewport like d3d9 clears are.