Attribute inheritance inconsistent across production and development

[privatenumber]

Version

3.2.31

Reproduction link

Provided below

Steps to reproduce

Open development and production links, compare whether class red-bg is applied to the button.

Development

• https://jsfiddle.net/hirokiosame/x0fmvoyL

• Vue SFC Link (Vue toggled in Import Map)

Production

• https://jsfiddle.net/hirokiosame/x0fmvoyL/2/

• Vue SFC Link (Vue toggled in Import Map)

What is expected?

For the development build to have consistent class inheritance logic as the production build

What is actually happening?

The class is only being inherited in development

[edison1105]

the root cause is:
the attribute could not be automatically inherited because component renders as a fragment in prod.
but in DEV, we do a special treatment for DEV_ROOT_FRAGMENT.

[edison1105]

duplicate of #5523

[iwusong]

duplicate of #5523

these are a little different

[yyx990803]

Duplicate of #5189 and fixed by 51f3d38

[iwusong]

Duplicate of #5189 and fixed by 51f3d38

now， a template ↓ , has attribute fallthrough

<template v-if="true">
  <span>test</span>
</template>

a template ↓ , has not attribute fallthrough

<template v-if="true">
  <!--flag-->
  <span>test</span>
</template>

Is this expected behavior?