Moving an element drops the ref

[skirtles-code]

Version

3.0.0-rc.5

Reproduction link

https://jsfiddle.net/skirtle/L79q43ya/6/

Steps to reproduce

1. Open the console log.
2. Click the button.
3. Note the ref inputEl is null.

What is expected?

inputEl should reference the appropriate element.

What is actually happening?

It's null.

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The example is attempting to move an input between the bottom and top of the component. It is only ever in one place at once so the template uses the same ref in both cases.

It seems that removing a VNode triggers a null ref during unmounting. This problem also impacted one of the examples in the documentation (see vuejs/docs#353).

I originally stumbled across this while using v-for with ref. Based on #1166 it would seem that may no longer be supported, so I removed it from my example. It's a bit unclear what's planned as I can't find an RFC and currently the Vue 3 documentation just describes the Vue 2 behaviour with a few additions about the composition API.