get_document on a class page says "no content" with no pointer to get_schema

Reading a class document (an XClass with fields but no body and no objects) returns Document has no content. and nothing else; the note that appears for object-carrying pages does not fire because there are no xobjects.

Expected: Note: this document defines a class with N field(s); get_schema class="<ref>" shows them.

Actual: No note.