[Interest] QWidget howto adapt contentsRect

[Frank Hemer]

How is it possible to have a QWidgets size requirement (height) to less than 
10px?

Setting minimumSize (x,0), maximumSize (x,0), setFixedSize (x,0) all doesn't 
help.
minimumSizeHint and sizeHint implementation doesn't help either.
What I found out is that the remaining 10px come from the contentsRect():-(

Thats easily reproducible when creating in designer (two pushbuttons, a widget 
in between and layout vertical.

Thx
Frank