[Interest] Looking for some tests of the offscreen QPA

[René J.V. Bertin]

Hi,

I've stumbled upon a shortcoming or bug in the offscreen QPA on Mac and written a tentative fix (https://bugreports.qt.io/browse/QTBUG-72335 and lined code review).

This works in my use-case but I'd like to run some more tests in order to see whether the issue is not in fact intentional and my fix introduces regressions. Not that it's likely; my fix is just a simplified copy of what the cocoa QPA does (and the "minimal" QPA as well).
I don't see any such tests in the Qt sources themselves, so suggestions and pointers (to existing code ;) ) are welcome.

Thanks,
R.