If there is no label in the use/setlang language and one views a diff, it get's displayed as:
Difference between revisions of ""
https://www.wikidata.org/w/index.php?title=Q1038&diff=11437&oldid=11421&uselang=en-ca
(this happens on my test repo instance with latest master, also)
Having a fallback there to the entity ID would be nice.
Version: master
Severity: normal