alan.schmitt@polytechnique.org writes:

> I tried to fix it in the updated attached patch. I set a default value
> of "foldmarks-not-set" to the predicate that detects if it is set in the
> file, then I compare its contents. This assumes that the user will not
> give this literal value to the option.

The attached version is updated to apply cleanly on master (after
applying your other patches).

Alan