MediaWiki core apparently supports multiple autocomments in a single edit message, which means that if you set an entity label to something like
deutsche Beschriftung /* wbsetlabel-set:1|en */ english Label /* wbcreateclaim-create:1| */ [[Property:P31]]: [[Q5]] a b
then the final summary will be
/* wbsetlabel-set:1|de */ deutsche Beschriftung /* wbsetlabel-set:1|en */ english Label /* wbcreateclaim-create:1| */ [[Property:P31]]: [[Q5]] a b
which will render like
which can be slightly misleading :)
(See here for such an example edit on test.wikidata.org.)
I’m not sure if there’s an easy solution to this. We should escape the label before appending it to the summary when creating the revision, but I couldn’t find any escaping format that wouldn’t still show up in the rendered summary (i. e., changing /* to /\* breaks the autocomment interpretation, but also shows the \ in the rendered message even though it’s not part of the actual label).
Are there any upcoming or planned core changes (perhaps part of MCR) that would split up the summary into autocomment and free-text field, or something else that might help here?