Undo in Title or Tagline block positions caret at start of field

[ironprogrammer]

Description

After Undo (Cmd+z) of a paste in the Title or Tagline block, the caret is (visually) positioned at the start of the field. However, subsequently pasted text is inserted at the end of the field, which is not expected based on caret position.

Expected behavior after Undo would be for:

• The caret to be positioned where it was prior to the last "undid" action, instead of defaulting to the start of the field.
• Pasted text to appear where the caret is positioned.

In testing a related issue, #64665, @Mamaduka also indicated:

...after digging, it turned out to be a general bug with the RichText component. The same behavior can be reproduced with Tagline block.

Problem

• RichText only "knows" how to re-adjust selection after undoing for block attribute values.
• When undoing entity properties, selection will point to the old start and end.

Step-by-step reproduction instructions

1. Add a new post or page.
2. Select the Title block and enter a title.
3. Paste additional text into the end of the field.
4. Undo the paste with Cmd+z/Ctrl+z (using the editor toolbar Undo button changes focus from the field, so is n/a).
5. Observe the location of the caret after undo (🐛 caret is moved to start of field).
6. Without clicking or repositioning the caret, re-paste into the field with Cmd+v/Ctrl+v.
7. Observe where the pasted text is inserted (🐛 text is inserted at end of field).

Screenshots, screen recording, code snippet

Demonstration of pasting text and resultant caret position. After Undo of paste caret appears to be at front but pastes at the end of the field.

Environment info

• Hardware: MacBook Pro Apple M1 Pro
• OS: macOS 14.6.1
• Browser: Safari 17.6
• Server: nginx/1.27.0
• PHP: 8.2.22
• MySQL: 8.0.27
• WordPress: 6.7-alpha-58576-src
• Theme: twentytwentyfour v1.2
• Active Plugins:
  • gutenberg v19.1.0-rc.1 (and v19.0.0 with patches applied from Post Title: Move selection at the end after pasting over the text #64665 and Post Title: Fix pasting in Safari #64671)

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