Stack Exchange switched their syntax highlighting parser to highlight.js (announcement). This is a clear downgrade for TeX (for now). However, highlight.js is said to be "actively developed" which makes me hopeful that this can be resolved in the medium term.
This question can be used to collect issues with the new syntax highlighting and track progress on solving them. Please
- post one answer per issue with a code snipped showing the problem,
- create an issue on highligh.js' Github page and
- mark the problem as solved in the answer when it has been resolved.
While this is really, really annoying, I believe it could also be an opportunity. The source file for the highlight.js LaTeX highlighting looks rather rudimentary, so we might be able to "take over" and improve it to our liking, maybe even improving some aspects of the old highlighting. I will try to find some time to get to know their system and see if I can't do that myself. Who knows, maybe we can finally get the LaTeX3 highlighting (as a separate language) I have been dreaming of..