Duplicate content in routeless engines

[thousand]

I spun up a new ember app with a routeless engine in-repo. The engine is mounted in the application.hbs file in the root application. Content that appears in the {{outlet}} of the root app's application.hbs template also appears where there is an {{outlet}} in the routeless engine's application.hbs.

I created a demo app to show this in action.

This is obviously a moot point since theoretically there isn't anything that should appear in the {{outlet}} of a routeless engine and the --type routeless argument doesn't include it, but it is pretty unexpected behavior. Maybe routeless engines can at least throw an error if they have an {{outlet}}?

[rwjblue]

Yikes. This is definitely a bug. I think that it is a bug in {{mount itself (which would make this a problem in Ember).