Reproduce: upload image & add MediaInfo entities.
Go to history, select first revision (from when there was no MediaInfo data yet)
Click "edit" - should take you to "restore" and show a diff.
Instead, you'll get this error:
[f36b83af22c5a24fe0efc0db] /w/index.php?title=File:a-new-file.jpg&action=mcrrestore&restore=575 RuntimeException from line 147 of /vagrant/mediawiki/extensions/Wikibase/repo/includes/Content/EntityContent.php: EntityContent was constructed without an EntityId!
Backtrace:
#0 /vagrant/mediawiki/extensions/Wikibase/repo/includes/Content/EntityContent.php(457): Wikibase\EntityContent->getEntityId()
#1 /vagrant/mediawiki/extensions/Wikibase/repo/includes/Content/EntityContent.php(572): Wikibase\EntityContent->getRedirectData()
#2 /vagrant/mediawiki/extensions/Wikibase/repo/includes/Diff/EntityContentDiffView.php(135): Wikibase\EntityContent->getDiff(Wikibase\MediaInfo\Content\MediaInfoContent)
#3 /vagrant/mediawiki/includes/diff/DifferenceEngineSlotDiffRenderer.php(58): Wikibase\Repo\Diff\EntityContentDiffView->generateContentDiffBody(Wikibase\MediaInfo\Content\MediaInfoContent, Wikibase\MediaInfo\Content\MediaInfoContent)
#4 /vagrant/mediawiki/includes/diff/DifferenceEngine.php(1056): DifferenceEngineSlotDiffRenderer->getDiff(Wikibase\MediaInfo\Content\MediaInfoContent, Wikibase\MediaInfo\Content\MediaInfoContent)
#5 /vagrant/mediawiki/includes/diff/DifferenceEngine.php(974): DifferenceEngine->getDiffBody()
#6 /vagrant/mediawiki/includes/actions/McrUndoAction.php(242): DifferenceEngine->getDiff(string, string)
#7 /vagrant/mediawiki/includes/actions/McrUndoAction.php(363): McrUndoAction->generateDiffOrPreview()
#8 /vagrant/mediawiki/includes/htmlform/fields/HTMLInfoField.php(25): McrUndoAction->{closure}(array)
#9 /vagrant/mediawiki/includes/htmlform/HTMLForm.php(1670): HTMLInfoField->getDefault()
#10 /vagrant/mediawiki/includes/htmlform/HTMLForm.php(1254): HTMLForm->displaySection(array, string)
#11 /vagrant/mediawiki/includes/htmlform/OOUIHTMLForm.php(252): HTMLForm->getBody()
#12 /vagrant/mediawiki/includes/htmlform/HTMLForm.php(1044): OOUIHTMLForm->getBody()
#13 /vagrant/mediawiki/includes/htmlform/HTMLForm.php(1023): HTMLForm->getHTML(boolean)
#14 /vagrant/mediawiki/includes/htmlform/HTMLForm.php(577): HTMLForm->displayForm(boolean)
#15 /vagrant/mediawiki/includes/actions/FormAction.php(143): HTMLForm->show()
#16 /vagrant/mediawiki/includes/actions/McrUndoAction.php(90): FormAction->show()
#17 /vagrant/mediawiki/includes/MediaWiki.php(506): McrUndoAction->show()
#18 /vagrant/mediawiki/includes/MediaWiki.php(294): MediaWiki->performAction(ImagePage, Title)
#19 /vagrant/mediawiki/includes/MediaWiki.php(873): MediaWiki->performRequest()
#20 /vagrant/mediawiki/includes/MediaWiki.php(530): MediaWiki->main()
#21 /vagrant/mediawiki/index.php(42): MediaWiki->run()
#22 /var/www/w/index.php(5): require(string)
#23 {main}