GC Crash With ObjectWrap + Exceptions #599

I am seeing crashes in the V8 GC when I have ObjectWraps that throw in subclass constructors. Example:

class MyObject : public ObjectWrap<MyObject> { MyObject(const CallbackInfo& info) : ObjectWrap<MyObject>(info) { throw Error::New(info.Env(), "something exceptional happened!"); } }

The ObjectWrap constructor will create a napi_ref for the object, associate this pointer and register a finalizer. If the subclass throws, the C++ runtime invalidates the this pointer. However, the pointer is still registered with the napi_ref. When the GC gets to the object, the finalizer tries to delete the invalid this and the system may crash.