Bug: Code Block Content Corrupted After HTML Export/Reimport

[daifuyang]

Describe the Bug

When exporting content containing code blocks to HTML and then reinitializing the Lexical editor with that HTML, the code block content becomes misformatted or corrupted. This issue occurs consistently when using the right-click paste method to insert code.

Lexical version: ^0.16.10

---

Steps to Reproduce

1. Insert a code block into the Lexical editor.
2. Copy and paste a code snippet into the editor by right-clicking and selecting "Paste".
3. Export the content to HTML.
4. Reload the page and initialize the Lexical editor with the previously exported HTML.
5. Observe that the code block content is now misformatted or corrupted.

---

Expected Behavior

The code block content should remain intact and properly formatted after exporting to HTML and reinitializing the Lexical editor with that HTML.

---

Current Behavior

The code block content becomes misformatted or corrupted after exporting to HTML and reinitializing the Lexical editor.

---

Code Example

stackblitz Example

---

Impact of Fix

• Severity: High, as it affects the integrity of code blocks, which are a common feature in text editors.
• Frequency: This issue occurs every time a code block is inserted via right-click paste and the content is exported/reimported.
• Beneficiaries: All users who rely on Lexical for handling code blocks, particularly developers and technical writers.
• Metrics: This fix would benefit a significant portion of Lexical users, especially those in technical fields who frequently work with code snippets.

---

Additional Context

Add any other context, screenshots, or logs about the bug here. For example:

• Screenshots of the misformatted code block.
• Browser and OS information (if relevant).
• Any workarounds currently being used.

[daifuyang]

Is it caused by the space of the label? Should this situation be handled by ourselves or by lexical?