oiiotool --origin and --fullpixels did not correctly propagate their changes
to the underlying ImageBuf's spec as well as the copy in the ImageRec.
But some other opertions would check the IB directly to determine iteration
ranges. So if you were operating on an image that was a crop window (i.e.,
different display and pixel windows), and did an --origin (or --fullpixels)
followed by another operation that used the IB's range directly, you could
end up with strangely offset results.