Unknown custom element error in nested functional components #10781
Description
Version
2.6.10
Reproduction link
https://codesandbox.io/s/vue-template-gg2gj
Steps to reproduce
Create two functional components, OuterComponent and InnerComponent.
Use InnerComponent in OuterComponent.
Use OuterComponent in your app somewhere.
What is expected?
InnerComponent should be recognized, as it's registered in OuterComponent's component option.
InnerComponent should render.
What is actually happening?
A unknown custom element error is thrown, and InnerComponent isn't rendered.
It will work if all the functional components used are registered in app.vue, even though they aren't used in app.vue's template.