[joy-ui][Autocomplete] Placeholder persists when values are selected in multiple mode

[joshuagoran]

Steps to reproduce

1. Open the Joy UI Autocomplete docs: https://mui.com/joy-ui/react-autocomplete/#multiple
2. Add a placeholder prop to the multiple Autocomplete, e.g.:

<Autocomplete
  multiple
  placeholder="Select items"
  options={['Apple', 'Banana', 'Cherry']}
/>

3. Select one or more values

Current behavior

The placeholder text remains visible alongside the selected chips. The placeholder is passed unconditionally to the internal <input> element's additionalProps:

https://github.com/mui/material-ui/blob/da8d6e8b2b2c7f3898af475de3a4beb6c0eaf3ab/packages/mui-joy/src/Autocomplete/Autocomplete.tsx#L521

Since the input's value is always empty in multiple mode (selected values render as chips, not input text), the HTML placeholder never clears.

Expected behavior

The placeholder should be hidden when one or more values are selected, matching the behavior of Joy UI's Select component which was fixed in #39806.

Context

The fix in #39806 addressed this for Select but was not applied to Autocomplete.

Your environment

System:
  OS: macOS 26.2
Binaries:
  Node: 24.11.0
  npm: 11.6.1
Browsers:
  Chrome: 144.0.7559.133
  Safari: 26.2
npmPackages:
  @mui/joy: 5.0.0-beta.52
  @emotion/react: 11.14.0
  @emotion/styled: 11.14.1
  react: 17.0.2

Order ID: N/A (open source usage)

Search keywords: joy autocomplete placeholder multiple chips

[albertdugba]

I have pushed a fix for this!

[ZeeshanTamboli]

Joy UI library is "on hold", so keeping this issue open. But the fix won't be merged because we don't plan to release a new version of Joy UI for now.