Description

The Math block accepts latex input, which can include ampersands (they are a separator character). After saving the post as a user without unfiltered_html capability and then reloading the editor or viewing the front-end, the ampersands are displayed as & rather than as a separator character.

Step-by-step reproduction instructions

1. Open the editor as a user without unfiltered_html cap, e.g. a Contributor
2. Add math block
3. Paste in this latex: \begin{pmatrix} a & b \\ c & d \end{pmatrix}
4. Look at the block preview
5. Save the post
6. Reload the editor
7. You can now see that the preview is incorrect the ampersands are showing up as literally & rather than as a separator.

Screenshots, screen recording, code snippet

Environment info

Gutenberg trunk (8dd0b92 - what will be 23.1), also reproduced on 23.0 and with GB plugin deactivated.

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