CropGeometry::with_angle replaced a crop that no longer fit at the new
angle with the largest centred crop of its aspect. For a crop dragged in
from a corner (which still touches two edges) that happened at the first
fraction of a degree, so the crop jumped back to nearly the whole photo.
A crop that no longer fits now shrinks about its own centre, keeping its
aspect, to the largest size that fits there. The full photo, or a crop
an earlier turn shrank to the largest of its aspect, still follows the
largest crop and grows back towards 0 degrees (#1388). A crop whose
centre is off the turned photo is centred at its own size at most. No
crop the user made ever grows.
Guillem Hermida
053b7420fe