positionViewAtEnd doesn't work properly if called from onContentHeightChanged

I've been finding this problem a couple of times.

I want a view that keeps scrolling down à la chat log and the implementation I preferred was to move the view to the bottom onContentHeightChanged (onCountChanged has the same effect, from the ListView).

The problem is that the view doesn't scroll to the end, it usually scrolls to half the last line and it's really ugly.

See the attached script. Run qmlviewer testscrolling.qml
There you'll see the filled list with a TextField, just press enter and you'll see the effect.

If I don't set a "section" then this doesn't happen.