the integer version of fillRect -> Graphics::fillRect (int x, int y, int width, int height)
aligns the coordinates to pixels, even when its in a context which is scaled.
The is inconsistent with other integer drawing functions like drawRect, so im pretty sure this is a bug.
(checked on windows)
You can see this very easily when a TreeView is scaled, which uses the integer version of fillRect and drawRect to draw the + - box
(the right version uses the float version of fillRect)