Apparently an exception is thrown when someone tries to undo a change in the history of an item that has become a redirect. This happend 14 times in the last 7 days, see logstash.
- Example of the exception: https://www.wikidata.org/w/index.php?title=Q60944051&action=edit&undoafter=943672202&undo=943672375
- History of the respective item: https://www.wikidata.org/w/index.php?title=Q60944051&action=history
Stacktrace:
Diff\Patcher\PatcherException from line 596 of /srv/mediawiki/php-1.34.0-wmf.5/extensions/Wikibase/repo/includes/Content/EntityContent.php: EntityContent must not contain Entity data as well as a redirect after applying
#0 /srv/mediawiki/php-1.34.0-wmf.5/extensions/Wikibase/repo/includes/Actions/EditEntityAction.php(265): Wikibase\EntityContent->getPatchedCopy(Wikibase\Repo\Content\EntityContentDiff)
#1 /srv/mediawiki/php-1.34.0-wmf.5/extensions/Wikibase/repo/includes/Actions/EditEntityAction.php(211): Wikibase\EditEntityAction->showUndoForm()
#2 /srv/mediawiki/php-1.34.0-wmf.5/includes/MediaWiki.php(499): Wikibase\EditEntityAction->show()
#3 /srv/mediawiki/php-1.34.0-wmf.5/includes/MediaWiki.php(294): MediaWiki->performAction(Article, Title)
#4 /srv/mediawiki/php-1.34.0-wmf.5/includes/MediaWiki.php(865): MediaWiki->performRequest()
#5 /srv/mediawiki/php-1.34.0-wmf.5/includes/MediaWiki.php(515): MediaWiki->main()
#6 /srv/mediawiki/php-1.34.0-wmf.5/index.php(42): MediaWiki->run()
#7 /srv/mediawiki/w/index.php(3): include(string)
#8 {main}