Using QGraphicsItem::setScale on a QGraphicsItem with flag ItemIgnoresTransformations results in wrong item movement

setScale() will somehow also have an effect when items are moved with the mouse via default handlers. For positive scale factors, the item will move less than it should, and vice versa. Scaling an item via setTransform() works properly. The documentation for the ItemIgnoresTransformations clearly states scaling should work, so I assume this is a bug.
Code reproducing error is attached.