static asset not working for poster attribute of video element in raw html

[Russiarain]

Describe the bug

static asset is not working for poster attribute of video element in raw html, but it works in custom vue component or manually import.

File structure

.
├─ docs                    # project root
│  ├─ .vitepress           # config dir
│  ├─ public
│    ├─ video.mp4
│    └─ poster.png
│  ├─ getting-started.md
│  └─ index.md
└─ ...

Reproduction

this doesn't work

<!-- in getting-started.md -->
<video src="/video.mp4" controls poster="/poster.png"></video>

but this works (manually import asset):

<!-- in getting-started.md -->
<script setup>
    import poster from "/poster.png";
</script>
<video src="/video.mp4" controls :poster="poster"></video>

this also works (static asset in custom component):

<!-- in MyVideo.vue -->
<template>
    <video src="/video.mp4" controls poster="/poster.png"></video>
</template>

<!-- in getting-started.md -->
<script setup>
    import MyVideo from "MyVideo.vue";
</script>

<MyVideo />

Expected behavior

static image asset should also work in raw video element in markdown file

System Info

System:
    OS: Windows 11 10.0.26200
    CPU: (16) x64 AMD Ryzen 9 5900HX with Radeon Graphics
    Memory: 4.16 GB / 15.42 GB
  Binaries:
    Node: 22.20.0 - C:\Program Files\nodejs\node.EXE
    npm: 10.9.0 - C:\Program Files\nodejs\npm.CMD
    pnpm: 10.17.1 - C:\Users\Frank\AppData\Roaming\npm\pnpm.CMD
  Browsers:
    Chrome: 141.0.7390.108
    Edge: Chromium (140.0.3485.54), ChromiumDev (140.0.3421.0)
    Internet Explorer: 11.0.26100.1882
  npmPackages:
    vitepress: ^2.0.0-alpha.12 => 2.0.0-alpha.12

Additional context

No response

Validations

• Check if you're on the latest VitePress version.
• Follow our Code of Conduct
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.

[brc-dd]

Please share a minimal reproducible example using some git repo. It's working fine for me.

[Russiarain]

Please share a minimal reproducible example using some git repo. It's working fine for me.

Sure. Please check out this repo.

It looks like this on my computer：

[brc-dd]

Hmm, I've no idea. But seems to be broken when navigating from other page. On reload it shows fine. The generated HTML is also fine. The poster is also accessible and the same markup is working for other element with similar rendered markup.

Probably it's some browser quirk. It works if I make it something like

<video src="/video.mp4#t=0.001" controls poster="/poster.png"></video>

It works without any hack on Firefox and Safari.

Adding playsinline attribute also fixes it. Some older answers suggest preload=none or preload=metadata but that doesn't seem to work.

Also, weird that it happens only with inline html in markdown regardless of the order. Maybe it's because it will hoisted since it's static. Even something like :data-foo="undefined" will make it dynamic vnode and it works.