A difference in overlapped widgets in null layouted composite
I thinks this is due because SWT null layout implementation use normal position:absolute behavior in which later dded children go on top of other siblings. Unfortunatly in SWT this seems to be inversed.
p.d: I don't think this fixing this bug is worthwhile. I really don't know even if SWT document the behavior of null layout with this respect. Nevertheless I think it's good to have this difference documented here...