Denis Auroux - 2019-02-06

Yes, this is a problem. For some older format PDFs, setting "Legacy PDF
export" in the options menu might bypass this, but most form-enabled
PDFs these days are in a format that our old PDF processing code can't
handle; in that case, the new export involves re-distilling via
gtk-print to a new PDF and right now form fields are lost; I don't know
how to fix this.

Denis