Pinch/spread to zoom uses wrong centerpoint
When pinching to zoom the canvas using 2.1 nightly on a touch device like Surface Pro, the zooming does often not act as expected. Instead of keeping the point between the two fingers fixed on the same place, instead it keeps another point fixed. Sometimes this is a point like the top right point of a frame which is selected, or the top right point of a selection box.
This is not the case for master (MS 3) which work as expected.
Could we consider to backport this behaviour?