[material-ui][InputBase] Text cursor jumps several lines up when inserting text fragment with new line at the end.

[Lastik]

Steps to reproduce

Steps:

1. Open this link to live example: Codesandbox
2. Type several lines of text to the InputBase text field. Your text cursor should be at the new empty line in the very end of the field.
3. Paste this text block at the end to the text field (including the empty line) several times in a row.

abc def abc def abc def

Current behavior

You should see that text cursor is not at the last empty line of the input anymore.

Expected behavior

Text cursor should still be at the last empty line of the input, because we are inserting to the end of it.

Context

This is basic usage of the component without any complex configurations or customizations.

Your environment

npx @mui/envinfo

  Browser Used: 
    Chrome
  System:
    OS: macOS 13.5.1
  Binaries:
    Node: 20.3.0 - /opt/homebrew/bin/node
    npm: 9.6.7 - /opt/homebrew/bin/npm
    pnpm: Not Found
  Browsers:
    Chrome: 132.0.6834.159
    Edge: Not Found
    Safari: 16.6
  npmPackages:
    @emotion/react: 11.14.0 => 11.14.0 
    @emotion/styled: 11.14.0 => 11.14.0 
    @mui/core-downloads-tracker:  6.4.2 
    @mui/material: 6.4.1 => 6.4.1 
    @mui/private-theming:  6.4.2 
    @mui/styled-engine:  6.4.2 
    @mui/system:  6.4.2 
    @mui/types:  7.2.21 
    @mui/utils:  6.4.2 
    @types/react:  19.0.8 
    react: 17.0.2 => 17.0.2 
    react-dom: 17.0.2 => 17.0.2 
    typescript: 4.1.3 => 4.1.3 

Search keywords: InputBase, material-ui, multiline, text cursor

[DiegoAndai]

Thanks for the report @Lastik! I can confirm this is a bug. It seems to be present in v5 as well as v6.

I added the ready to take label in case anyone wants to work on this before the team gets to it. Please reach out if you're interested, I'll gladly guide you.

[yermartee]

Hi @DiegoAndai I would like to work on this issue.

[suhel4code]

Wanted to take on this

[DiegoAndai]

Hi @yermartee, go ahead! Feel free to let me know if you need any help. Thanks in advance.

@suhel4code, thanks for the interest; I will assign this one to @yermartee, as he asked first. I'll gladly guide you in other ready to take issues.