I noticed an unexpected behaviour of the crop tool when it is opened after a perspective correction has been applied.
This is the starting point:
This is how it looks after application of a horizontal-only auto correction:
This is what I get when I open the crop tool:
As we can see, the crop frame has changed. It does not display the crop as applied in step 2. Although the width is as expected, the top and bottom edges have moved inwards.
In order to maximise the cropped image area and display the frame accordingly, I have to set the crop ratio to “Original” and back to “Unconstrained” and close the tool. The resulting crop corresponds to the automatic crop as applied in step 2. This means that automatic unconstrained crop works, but displays off-position crop frames under the conditions mentioned above.
BUT: Closing the crop tool will display a correctly cropped image, even with a frame that should create a different crop.