[322769faea345c08bf13fac0] /index.php/Special:ChangeContentModel/Gadget_definition:Foobar Exception: Tried to save non-GadgetDefinitionContent to Gadget definition:Foobar
Deliberately being thrown in GadgetHooks::onEditFilterMergedContent (though with // this should not be possible? comment which indicates invocation via ChangeContentModel may have been overlooked).