RichText component: pasting text ignores disableLineBreaks setting

[markhowellsmead]

Description

When pasting text into a RichText component with disableLineBreaks={true}, the line breaks (\r and \n) are replaced with br tags instead of being stripped. Possibly related: #59548.

Step-by-step reproduction instructions

See code below. Copy and paste a text into the field which contains plain text line breaks (not br tags).

Screenshots, screen recording, code snippet

const {attributes, setAttributes} = props;
const {title} = attributes;

 <RichText
    tagName='h3'
    placeholder=__('Add a title…', 'sha')}
    value={title}
    allowedFormats={[]}
    disableLineBreaks={true}
    onChange={value => {
        setAttributes({ title: value });
    }}
    />

Environment info

• WordPress 6.7.1

Please confirm that you have searched existing issues in the repo.

• Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

• Yes

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure

[markhowellsmead]

cc @t-hamano.

[t-hamano]

@markhowellsmead Thanks for the report. I was able to reproduce this issue too.

My test steps are as follows:

• Insert a Site Tagline block. Inside this block, the RichText component has disableLineBreaks applied to it.
• Enter text, including line breaks, into the text area.
• Copy it and paste it into the Site Tagline block.

cd2f4c0c4fda768d3d89750b6be15d57.mp4

My feeling is that this isn't intended. Perhaps the disableLineBreaks prop needs to check for the paste event as well as the Enter key.

cc @ellatrix

[markhowellsmead]

Thanks Aki!

[Infinite-Null]

Hi @t-hamano, @markhowellsmead,

I’ve submitted a PR #67412 with a potential solution and would greatly appreciate it if you could take a moment to test and review it. Your feedback would be valuable.

Thank you for your time.