[Bug] In a footnote, `~~~`, with any syntax highlight designator – except `txt` – does not apply highlighting, and renders with a `font-size` < `1em`.

[beedell-roke]

As originally discussed at github-linguist/linguist/issues/7637, when a CommonMark <pre><code> (~~~) with a syntax highlight declaration (~~~RegEx) is utilised inside a Markdown footnote, its font-size reduces, and the syntax highlight designation is not applied, such that it reproduces issues/1851:

Reproductive Markup

[^1]

[^1]: ~~~MA
 "(?:(?:headers)|(?:cookies))"\s*:\s*(?:\{[^{}]*\}|\[[^\[\]]*\]|"[^"]*"|[^,}\]]*)(?:,)?\s*
 
 ~~~

Comparison Of Correct And Incorrect Presentation

~~~RegEx	~~~txt

Affected

Details

1. ValveSoftware/steam-for-linux/issues/12350#issuecomment-3392070179

2. warpdotdev/warp/issues/9211#issuecomment-4361821404

¹

Footnotes

1. issues/1811 ↩

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[beedell-roke]

@github-actions, see #issuecomment-2809414223.

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[beedell-roke]

@github-actions, see #issuecomment-2809414223.

[zkoppert]

Thanks for the report.

After investigating, this is about font-size and syntax highlighting within footnote code blocks. Syntax highlighting is handled by github/linguist (step 3 of the rendering pipeline), not by this repository.

This repo (github/markup) only handles step 1: converting markup formats to raw HTML. Check out this part of the README for a fuller picture:

Please note that only the first step is covered by this gem — the rest happens on GitHub.com's backend.

For syntax highlighting and code block rendering feedback, GitHub's feedback discussions or the linguist repo would be better venues.

Closing as out of scope for this repository.