Today Ī̲ stumbled upon a bizarre link https://www.wikidata.org/w/index.php?title=Property:P4575&curid=44760560&diff=1470987750&oldid=1470987750&diffmode=source in the watchlist (in words: both diff and oldid point to the latest revision) instead of the expected diff spanning two consecutive edits. The link text misleadingly says “2 changes”, but the associated mw-diff-bytes (appropriately) shows “0”. At https://www.wikidata.org/wiki/User:Incnis_Mrsi/Property:P4575 you can see HTML source (with minor changes pertaining to MediaWiki rendering).
This doesn’t look like a browser glitch. Why Special:Watchlist compares the last revision with itself?