Note from testing at https://test2.wikipedia.org/wiki/Talk:T364639

This appears to WORK when using discussion tools, but fails when using the wikitext editor with automatic summaries

Based on reports in https://en.wikipedia.org/w/index.php?title=Wikipedia:Village_pump_(technical)&oldid=1223218225#Anchor_issue_with_LT/GT_symbols_(redux) this appears to have broken between 2024-04-04 and 2024-04-10

Strike this, the working one seems to have used DT - still looking for an example of this working with wikitext

Note that the last time this worked was https://en.wikipedia.org/w/index.php?diff=1211086114 (29 Feb 2014), which was before T358810 was filed.

In T364639#9786679, @Primefac wrote:

Note that the last time this worked was https://en.wikipedia.org/w/index.php?diff=1211086114 (29 Feb 2014), which was before T358810 was filed.

That one appears to be via discussion-tools as well though, are you positive it was not? This bug only seems to be presenting under wikitext section editor right now.

You are correct, I forgot to double-check for that. As indicated at the on-wiki discussion, this might have never worked as intended (a 2014 edit shows the same issue).

In T364639#9786579, @Xaosflux wrote:

Note from testing at https://test2.wikipedia.org/wiki/Talk:T364639

This appears to WORK when using discussion tools, but fails when using the wikitext editor with automatic summaries

Discussion tools has a smarter way of generating the section link in the summary: it generates it from the heading in the parsed HTML, rather than directly from the heading wikitext. This is a bit more difficult to do in the normal editor, where the possible kinds of edits are not constrained.