Copy/paste handler not working in RichText component in block

[t-hamano]

Description

If there is a RichText component in a block, such as caption text, the copy/paste handler does not seem to work on that RichText.

• This problem is not reproduced when the block itself is a RichText component, such as a paragraph block.
• I have tested on Windows OS and this problem occurs in Chrome and not in Firefox.
• This problem occurs when the latest Gutenberg is enabled.

It would be great if you could test this issue, especially on MacOS, as the results may vary depending on the OS and browser.

Step-by-step reproduction instructions

• Insert a block that contains a RichText component.
• Enter text in the RichText component. For example, the caption in the Image block, cells, and caption in the Table blocks, etc.
• Press the Ctrl + C key. Here, the text should be saved to the clipboard.
• Press the Ctrl + V key elsewhere. In certain browsers, the text should not be pasted.

Screenshots, screen recording, code snippet

bdfac779fc632dfba235c4c1a5dfdb96.mp4

Environment info

• Gutenberg version: 16.4.0-rc.1
• Browser:
  • Chrome 115.0.5790.171: This problem occurs
  • Firefox 115.0.3: This problem does not occur

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

[t-hamano]

I used git bisect and tracked down the issue to where it was caused by #48254. I would like to explore the cause further.

[t-hamano]

Perhaps we should check to see if the problem reported in #48040 has been resolved on all OS/browsers before resolving this issue.

[stokesman]

I tested on macOS and could reproduce the problem in Chrome, Safari, Orion, Firefox.

[mrfoxtalbot]

This issue came up in the support forums and I can reproduce this with WP 6.3 and the Gutenberg plugin active (Version 16.5.0). A few more details I noticed:

• The bug is not present when the plugin is deactivated. WP 6.3 on its own works fine
• If the text is unformatted, the pasting works.
• if the "paste as plain text" is used, it works too.