Wow. 6 1/2 years since the original post. We’re up to PL8 now and constraining a crop to the image area is still not possible.
Cropping a rotated image in PhotoLab is so frustrating that it makes me wonder if anyone at DxO actually uses their own software. Please… DxO engineers… how do you maximize the image area without dipping into the black non-image area? Try it yourself and tell me there’s no problem.
And the next step would be to add some background to the black areas, if the limit exceeds the transformated picture.
more than 7 1/2 years: The original request was 2017-05 in the old forum.
DxO seems to invest more time in license checks (New Licensing in Preparation with PhotoLab 7.7? or License could not be verified ad startup) than repairing long standing issues.
One option is to stay with 7.6 as long as you can activate it and not pay for newer versions.