The problem is that unforgeables get copied onto descendant interfaces. But the signature is not the same for JS-implemented and C++-implemented, so this: [Unforgeable] readonly attribute long unforgeableAttr; gives a "int32_t GetUnforgeableAttr(ErrorResult&)" member on the autogenerated C++ implementation for the JS-implemented interface but a call like: self->UnforgeableAttr(); in the binding for the C++-implemented interface. And vice versa if the JS-implemented thing inherits from a C++-implemented thing. The good news is that unforgeable stuff is rare...

The bad news is that we have JS-implemented events and want to make Event.isTrusted unforgeable. I suppose we could flag copied unforgeable stuff so we don't munge its signature... Any brighter ideas?

Or I just make MozInterAppMessageEvent (which is currently the only JS implemented event) to use webidl event codegen ;) I removed some JS implementations few days ago, but apparently missed MozInterAppMessageEvent.

https://bugzilla.mozilla.org/show_bug.cgi?id=1472046 Move all DOM bugs that haven’t been updated in more than 3 years and has no one currently assigned to P5. If you have questions, please contact :mdaly.