Setting QSpinBox border stylesheet screws up rendering

[cowo78]

Setting a stylesheet that manipulates border destroys QSpinBox functionality using master@30decc8a, both on Linux/X11 and Windows 10.

In detail:

• border-color has no visible effect
• border-width has no visible effect
• complete border specification is not working, rendering screwed up, down button not clickable
• border-style is not working, rendering better than the above, down button not clickable
• border-radius is NOT working, same as border-style

Attached is the QT spinboxes example with a stylesheet that demonstrates the problem. At the head of window.cpp you can find some more stylesheet options.
AdwaitaTest.zip

[grulja]

I'm not sure this is something we will fix anytime soon as adding support for stylesheets is not trivial. I will keep this open if anyone wants to work on this.