Static slot content vnode's el property remains null after the component is mounted

[oliverzy]

Vue version

3.2.40

Link to minimal reproduction

https://sfc.vuejs.org/#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

Steps to reproduce

See the vue sfc playground link.

What is expected?

Switch Vue version to 3.2.39, the output is the dom element which is correctA.

What is actually happening?

Switch Vue version to 3.2.40，the output is null which is wrong.

System Info

No response

Any additional comments?

No response

[zhangzhonghe]

It should be caused by the change here.

core/packages/runtime-core/src/vnode.ts

Lines 738 to 744 in fc5bdb3

	// optimized normalization for template-compiled render fns
	export function cloneIfMounted(child: VNode): VNode {
	return (child.el === null && child.patchFlag !== PatchFlags.HOISTED) ||
	child.memo
	? child
	: cloneVNode(child)
	}

see #6591

[baiwusanyu-c]

As @zhangzhonghe said, when fixing bug #6591 , @yyx990803 removed the reference to the dom on the hoisted vnodes to avoid memory leaks, you can bind a key to avoid hoisted

<template>
  <Comp><div key='wqewqewq'>
    wqewqewq
    </div></Comp>
</template>

[oliverzy]

This is technically a breaking change, I think the workaround above is not ideal

[zhangzhonghe]

duplicate of #815

This is not a breaking change!

[oliverzy]

OK, strictly speaking, it's an undocumented internal api change since 3.2.40.
Let's see how can we proceed with this. One of our internal component library relies on this behavior, currently we have to lock the vue version to 3.2.39 for quick fix.

[LinusBorg]

I don't think labeling this as an important bug is warranted. it's essentially an edge case when using an API that's not even public, strictly speaking.