The regex governing this is const altRegex = /!\[(?:Image_alt_text)?\](?:\(.+(?!\\\))\)|\[.+(?!\\\])\])/gi; (in app/assets/javascripts/markdown.js, but if I try to touch a regex I might cause the world to end or something. Happy to get a PR from someone with more clues than I have!

The regex would have to check whether the text is inside or outside a code block, which includes single back ticks, triple back ticks, code tags, plus all the back tick variations that markdown allows for special use cases. This would mean effectively writing a markdown renderer in regex, which would be horrible to maintain and almost certainly incorrect (regex would not be a suitable tool for this).

It sounds like fixing this issue would require somehow hooking into the existing markdown renderer, or processing the already rendered html, either of which would be a non trivial task.

Since I would expect this issue to come up very rarely (I only saw it because I was raising another issue about the alt text) it may not be worth fixing. I tried to hint in the post that this should probably be very low priority.