srcset with base64 value is mangled on build

[elringus]

Describe the bug

Consider following html:

<img srcset="data:image/avif;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAYAAACNMs+9AAAAFUlEQVR42mNk+M9Qz0AEYBxVSF+FAAhKDveksOjmAAAAAElFTkSuQmCC" />

When built with Vite (in both dev and build, w/o any plugins or JS, just static HTML build), output html is:

<img srcset="data:image/avif;base64 , iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAYAAACNMs+9AAAAFUlEQVR42mNk+M9Qz0AEYBxVSF+FAAhKDveksOjmAAAAAElFTkSuQmCC " />

Notice added spaces around comma and at the end of the srcset value.

Reproduction

https://stackblitz.com/edit/vitejs-vite-yvgacv?file=index.html

Steps to reproduce

1. Open the repro on stackblitz, it'll automatically run vite dev
2. Notice the image is not rendered due to malformed srcset value
3. Exit vite dev and run npx serve
4. Notice the image is rendered correctly

System Info

System:
    OS: Windows 10 10.0.19045
    CPU: (16) x64 Intel(R) Core(TM) i7-6900K CPU @ 3.20GHz
    Memory: 48.15 GB / 63.92 GB
  Binaries:
    Node: 21.4.0 - C:\Program Files\nodejs\node.EXE
    Yarn: 1.22.19 - ~\AppData\Roaming\npm\yarn.CMD
    npm: 9.6.6 - C:\Program Files\nodejs\npm.CMD
    pnpm: 7.29.3 - C:\ProgramData\chocolatey\bin\pnpm.EXE
  Browsers:
    Chrome: 120.0.6099.111
    Edge: Chromium (120.0.2210.91)

Used Package Manager

npm

Logs

No response

Validations

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• The provided reproduction is a minimal reproducible example of the bug.

[stackblitz]

Start a new pull request in StackBlitz Codeflow.

• vitejs-vite-yvgacv (Open reproduction)