See https://en.wikipedia.org/w/index.php?diff=775948950&oldid=775948927
Expected section heading: == Add SNAC ID ==
Actual section heading: == /* Add SNAC ID */ new section ==
Originally reported by @Sadads on a Chromebook at https://www.mediawiki.org/wiki/Topic:Tow1hz9eve3gn48p
I can't actually persuade this to happen. Can anyone else, who can then provide better reproduction steps?
That said, EditPage.php contains numerous comments along the lines of "use summary as sectiontitle, ugh, we really should stop doing this". Our work in ArticleTarget tries to avoid providing a summary and a sectiontitle at the same time, but perhaps there's a loophole I'm not seeing which would result in the summary getting passed in....
In T248364 we found out that the same problem can happen when saving the edit causes an edit conflict, which results in switching to the old wikitext editor. But in this edit, I don't see anything that would indicate that an edit conflict or editor switching was involved, so it's still unexplained.
Unfortunately closing this Phabricator task as no further information has been provided in the last 3.5 years.
If this still happens and anyone can still reproduce this, please set the status of this task back to "Open" via the Add Action... → Change Status dropdown and provide a link to that edit plus good steps to reproduce. Thanks!