TouchEvent::TouchPoint::pos was not updated in
QGraphicsScenePrivate::updateTouchPointsForItem().
To prevent the transformation being calculated repeatedly for each touch
point member, extract a function genericMapFromSceneTransform()
from genericMapFromScene() returning the transformation and use
that whereever multiple points are transformed.
Add a test, extracting helper functionality from
tst_QGraphicsItem::touchEventPropagation().
In addition, fold tst_QGraphicsScene::checkTouchPointsEllipseDiameters() from
c48f4bde00 into this test, so that
it is testing all transformations.
Task-number: QTBUG-66192
Change-Id: If71886d2c14c4e216f7781ea2f22f1adc444e6cf
Reviewed-by: Andy Shaw <andy.shaw@qt.io>
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>
ed3ed0b9db