"v-slot" abbreviated syntax for default slot does not observe components using is="component-name"

[ryaninvents]

Version

2.6.10

Reproduction link

https://codesandbox.io/s/elated-sun-8npx9?file=/src/App.vue

Steps to reproduce

Error message displays immediately when viewing repro.

What is expected?

Vue should recognize that the given v-slot is attached to a component, because the element has the is="hello-world" attribute set.

What is actually happening?

Vue sees the v-slot attribute on a section element, and assumes it is an error.

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Ordinarily I'd just rewrite my code to directly reference the component (without the is= attribute) but I'm rehydrating server-rendered content and need the wrapper to be semantic.

[posva]

Duplicate of #10152