Visual diffs on translateable pages highlight unchanged translation markers as added and removed.

Example: https://www.mediawiki.org/w/index.php?title=API:Options&curid=87841&diff=5643034&oldid=5643033&diffmode=visual

Visual diff	Wikitext diff

The expected behavior is that only the markers around "Anonymous users cannot change preferences" should be highlighted as added. There should be no red or green highlights below. (Ideally the highlighted markers also wouldn't be invisible, but that doesn't seem that important.)