Previously, a region that used size snapping could be dragged to a
snapped size (say 3 times a column width), but then would be clamped to
an unsnapped size (say 2.7 times a column width) to make it fit the
available space.
Instead clamp the size before snapping, so that snapping respects the
available width/height (resulting in 2 times a column width for
example). Put differently, the region will not be made taller if there's
not enough space to fit the region up to the next snapping point.
Julian Eisel