If MediaWiki:Abusefilter-blocker is invalid in the content language, the filter user falls back to the English version, but that English version could also be invalid on a wiki - we should use Message::useDatabase() to ensure that the English version is fetched from the i18n files, rather than onwiki
Demo:
On beta metawiki, set https://meta.wikimedia.beta.wmflabs.org/wiki/MediaWiki:Abusefilter-blocker to Abuse filter #test and trigger a filter that will try to block the user
Result:
[YLsNXJQ08eKxOGcOSgAEvwAAAAA] /w/index.php?title=User:DannyS712/sandbox&action=submit TypeError: Argument 1 passed to MediaWiki\User\UserGroupManager::getUserGroups() must implement interface MediaWiki\User\UserIdentity, null given, called in /srv/mediawiki/php-master/extensions/AbuseFilter/includes/FilterUser.php on line 61
Backtrace:
from /srv/mediawiki/php-master/includes/user/UserGroupManager.php(651)
#0 /srv/mediawiki/php-master/extensions/AbuseFilter/includes/FilterUser.php(61): MediaWiki\User\UserGroupManager->getUserGroups(NULL)
#1 /srv/mediawiki/php-master/extensions/AbuseFilter/includes/Consequences/Consequence/BlockingConsequence.php(78): MediaWiki\Extension\AbuseFilter\FilterUser->getUser()
#2 /srv/mediawiki/php-master/extensions/AbuseFilter/includes/Consequences/Consequence/Block.php(62): MediaWiki\Extension\AbuseFilter\Consequences\Consequence\BlockingConsequence->doBlockInternal(string, integer, string, string, boolean, boolean)
#3 /srv/mediawiki/php-master/extensions/AbuseFilter/includes/Consequences/ConsequencesExecutor.php(317): MediaWiki\Extension\AbuseFilter\Consequences\Consequence\Block->execute()
#4 /srv/mediawiki/php-master/extensions/AbuseFilter/includes/Consequences/ConsequencesExecutor.php(98): MediaWiki\Extension\AbuseFilter\Consequences\ConsequencesExecutor->takeConsequenceAction(MediaWiki\Extension\AbuseFilter\Consequences\Consequence\Block)
#5 /srv/mediawiki/php-master/extensions/AbuseFilter/includes/FilterRunner.php(261): MediaWiki\Extension\AbuseFilter\Consequences\ConsequencesExecutor->executeFilterActions(array)
#6 /srv/mediawiki/php-master/extensions/AbuseFilter/includes/AbuseFilterHooks.php(102): MediaWiki\Extension\AbuseFilter\FilterRunner->run()
#7 /srv/mediawiki/php-master/extensions/AbuseFilter/includes/AbuseFilterHooks.php(45): MediaWiki\Extension\AbuseFilter\AbuseFilterHooks::filterEdit(DerivativeContext, User, WikitextContent, string, string)
#8 /srv/mediawiki/php-master/includes/HookContainer/HookContainer.php(338): MediaWiki\Extension\AbuseFilter\AbuseFilterHooks::onEditFilterMergedContent(DerivativeContext, WikitextContent, Status, string, User, boolean)
#9 /srv/mediawiki/php-master/includes/HookContainer/HookContainer.php(137): MediaWiki\HookContainer\HookContainer->callLegacyHook(string, array, array, array)
#10 /srv/mediawiki/php-master/includes/HookContainer/HookRunner.php(1498): MediaWiki\HookContainer\HookContainer->run(string, array)
#11 /srv/mediawiki/php-master/includes/editpage/Constraint/EditFilterMergedContentHookConstraint.php(90): MediaWiki\HookContainer\HookRunner->onEditFilterMergedContent(DerivativeContext, WikitextContent, Status, string, User, boolean)
#12 /srv/mediawiki/php-master/includes/editpage/Constraint/EditConstraintRunner.php(88): MediaWiki\EditPage\Constraint\EditFilterMergedContentHookConstraint->checkConstraint()
#13 /srv/mediawiki/php-master/includes/EditPage.php(2276): MediaWiki\EditPage\Constraint\EditConstraintRunner->checkConstraints()
#14 /srv/mediawiki/php-master/includes/EditPage.php(1695): EditPage->internalAttemptSave(NULL, boolean)
#15 /srv/mediawiki/php-master/includes/EditPage.php(670): EditPage->attemptSave(NULL)
#16 /srv/mediawiki/php-master/includes/actions/EditAction.php(71): EditPage->edit()
#17 /srv/mediawiki/php-master/includes/actions/SubmitAction.php(38): EditAction->show()
#18 /srv/mediawiki/php-master/includes/MediaWiki.php(536): SubmitAction->show()
#19 /srv/mediawiki/php-master/includes/MediaWiki.php(320): MediaWiki->performAction(Article, Title)
#20 /srv/mediawiki/php-master/includes/MediaWiki.php(917): MediaWiki->performRequest()
#21 /srv/mediawiki/php-master/includes/MediaWiki.php(551): MediaWiki->main()
#22 /srv/mediawiki/php-master/index.php(53): MediaWiki->run()
#23 /srv/mediawiki/php-master/index.php(46): wfIndexMain()
#24 /srv/mediawiki/w/index.php(3): require(string)
#25 {main}Similar underlying cause as T53837