Slot children with v-if are inserted in the wrong order under certain conditions

[basuneko]

Vue version

3.4.31

Link to minimal reproduction

https://github.com/basuneko/vue-conditional-rendering-bug

Steps to reproduce

Build and preview the app - the issue does not occur when running through the dev server

npm run build
npm run preview

Open the app and view the examples.

All cases contain the same set of divs:

<div v-if="showFirstChild">1</div>
<div>2</div>
<div>3</div>

showFirstChild is set to true after a 100ms delay

What is expected?

After a short delay, the three divs should appear in this order: 1, 2, 3

What is actually happening?

The first example renders 2, 3, 1.
If the timeout is set to 0, the result becomes a bit random - sometimes it renders 1, 2, 3, sometimes 2, 3, 1.

System Info

System:
    OS: macOS 14.5
    CPU: (12) arm64 Apple M2 Pro
    Memory: 54.47 MB / 32.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 20.11.1 - ~/.nodenv/versions/20.11.1/bin/node
    Yarn: 1.22.22 - ~/.nodenv/versions/20.11.1/bin/yarn
    npm: 10.8.1 - ~/.nodenv/versions/20.11.1/bin/npm
    pnpm: 9.5.0 - ~/.nodenv/versions/20.11.1/bin/pnpm
    Watchman: 2024.06.10.00 - /opt/homebrew/bin/watchman
  Browsers:
    Chrome: 126.0.6478.127
    Safari: 17.5
  npmPackages:
    vue: ^3.4.31 => 3.4.31

vite 5.3.3
@vitejs/plugin-vue 5.0.5

Any additional comments?

I needed to add a flexbox wrapper to the slot content. It was working fine while running through vite dev server, but then I pushed it to CI...

I don't know what the significance of Vuetify here is but I've only been able to reproduce this with VMenu and VDialog. They render their content outside of the normal component hierarchy. I think they use Teleport but possibly using Teleport? I don't fully understand how they work.

For reference VMenu

[edison1105]

maybe duplicate of #7256

It works fine without vuetify, see
Could you provide a minimal reproduction without vuetify?

[yyx990803]

It's related to #10870, I've found the fix. Writing tests now.