Vuex Store undefined SSR with component as both child and root

[0Rick0]

Version

3.6.2

Reproduction link

github.com

Steps to reproduce

• Create two components (CompA and CompB)
• CompB uses CompA as a child
• Create a simple store
• Extend CompB with the store
• Create Vue instance of CompB (instanceB)
• Render instanceB with SSR (renderToString)
• Extend CompA with store
• Create Vue instance of CompA (instanceA)
• Render instanceA with SSR
• Try to extract the store's state of instanceA

What is expected?

instanceA's and instanceB's $store should be defined

What is actually happening?

instanceA's store is undefined instanceB's store was defined

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It appears that after a component has been used as a child component, it can no longer be used as a root component. As of yet I haven't managed to reproduce the bug in a normal client app. See the minimal reproduction repo for an example.

Not sure if this bug should be logged with Vuex or with Vue.