During the cropping step if you draw the rectangle big enough to go outside the bounds of the image (which is a "valid" case when the image you're trying to crop ends right at the edge) and then you switch to Save, no cropping occurs. However there is no warning that something is wrong, in case the rectangle is drawn outside the bounds it should automatically clamp to bounds or at least provide a warning that the rectangle needs to be 100% inside the image bounds.
During the cropping step if you draw the rectangle big enough to go outside the bounds of the image (which is a "valid" case when the image you're trying to crop ends right at the edge) and then you switch to Save, no cropping occurs. However there is no warning that something is wrong, in case the rectangle is drawn outside the bounds it should automatically clamp to bounds or at least provide a warning that the rectangle needs to be 100% inside the image bounds.