Steps to reproduce:
Visit https://en.wikipedia.beta.wmflabs.org/wiki/Wikipedia:Quick_directory
Result:
Hidden comment DiscussionTools could not add reply links on this page is added
Checking logstash beta for the relevant request (X6NtcKwQBHcAABxZd80AAAAK) shows 2 errors:
TypeError from line 81 of /srv/mediawiki/php-master/extensions/DiscussionTools/includes/ImmutableRange.php: Argument 4 passed to MediaWiki\Extension\DiscussionTools\ImmutableRange::__construct() must be of the type integer, null given, called in /srv/mediawiki/php-master/extensions/DiscussionTools/includes/CommentParser.php on line 778 #0 /srv/mediawiki/php-master/extensions/DiscussionTools/includes/CommentParser.php(778): MediaWiki\Extension\DiscussionTools\ImmutableRange->__construct(DOMText, integer, DOMText, NULL) #1 /srv/mediawiki/php-master/extensions/DiscussionTools/includes/CommentParser.php(1098): MediaWiki\Extension\DiscussionTools\CommentParser->buildThreadItems() #2 /srv/mediawiki/php-master/extensions/DiscussionTools/includes/CommentParser.php(723): MediaWiki\Extension\DiscussionTools\CommentParser->buildThreads() #3 /srv/mediawiki/php-master/extensions/DiscussionTools/includes/CommentFormatter.php(22): MediaWiki\Extension\DiscussionTools\CommentParser->getThreadItems() #4 /srv/mediawiki/php-master/extensions/DiscussionTools/includes/Hooks.php(182): MediaWiki\Extension\DiscussionTools\CommentFormatter->addReplyLinks() #5 /srv/mediawiki/php-master/includes/HookContainer/HookContainer.php(333): MediaWiki\Extension\DiscussionTools\Hooks::onOutputPageBeforeHTML(OutputPage, string) #6 /srv/mediawiki/php-master/includes/HookContainer/HookContainer.php(140): MediaWiki\HookContainer\HookContainer->callLegacyHook(string, array, array, array) #7 /srv/mediawiki/php-master/includes/HookContainer/HookRunner.php(2728): MediaWiki\HookContainer\HookContainer->run(string, array) #8 /srv/mediawiki/php-master/includes/OutputPage.php(2007): MediaWiki\HookContainer\HookRunner->onOutputPageBeforeHTML(OutputPage, string) #9 /srv/mediawiki/php-master/includes/OutputPage.php(2019): OutputPage->addParserOutputText(ParserOutput, array) #10 /srv/mediawiki/php-master/includes/page/Article.php(844): OutputPage->addParserOutput(ParserOutput, array) #11 /srv/mediawiki/php-master/includes/actions/ViewAction.php(74): Article->view() #12 /srv/mediawiki/php-master/includes/MediaWiki.php(530): ViewAction->show() #13 /srv/mediawiki/php-master/includes/MediaWiki.php(316): MediaWiki->performAction(Article, Title) #14 /srv/mediawiki/php-master/includes/MediaWiki.php(943): MediaWiki->performRequest() #15 /srv/mediawiki/php-master/includes/MediaWiki.php(546): MediaWiki->main() #16 /srv/mediawiki/php-master/index.php(53): MediaWiki->run() #17 /srv/mediawiki/php-master/index.php(46): wfIndexMain() #18 /srv/mediawiki/w/index.php(3): require(string) #19 {main}
ErrorException from line 778 of /srv/mediawiki/php-master/extensions/DiscussionTools/includes/CommentParser.php: PHP Notice: Trying to get property 'length' of non-object #0 /srv/mediawiki/php-master/extensions/DiscussionTools/includes/CommentParser.php(778): MWExceptionHandler::handleError(integer, string, string, integer, array) #1 /srv/mediawiki/php-master/extensions/DiscussionTools/includes/CommentParser.php(1098): MediaWiki\Extension\DiscussionTools\CommentParser->buildThreadItems() #2 /srv/mediawiki/php-master/extensions/DiscussionTools/includes/CommentParser.php(723): MediaWiki\Extension\DiscussionTools\CommentParser->buildThreads() #3 /srv/mediawiki/php-master/extensions/DiscussionTools/includes/CommentFormatter.php(22): MediaWiki\Extension\DiscussionTools\CommentParser->getThreadItems() #4 /srv/mediawiki/php-master/extensions/DiscussionTools/includes/Hooks.php(182): MediaWiki\Extension\DiscussionTools\CommentFormatter->addReplyLinks() #5 /srv/mediawiki/php-master/includes/HookContainer/HookContainer.php(333): MediaWiki\Extension\DiscussionTools\Hooks::onOutputPageBeforeHTML(OutputPage, string) #6 /srv/mediawiki/php-master/includes/HookContainer/HookContainer.php(140): MediaWiki\HookContainer\HookContainer->callLegacyHook(string, array, array, array) #7 /srv/mediawiki/php-master/includes/HookContainer/HookRunner.php(2728): MediaWiki\HookContainer\HookContainer->run(string, array) #8 /srv/mediawiki/php-master/includes/OutputPage.php(2007): MediaWiki\HookContainer\HookRunner->onOutputPageBeforeHTML(OutputPage, string) #9 /srv/mediawiki/php-master/includes/OutputPage.php(2019): OutputPage->addParserOutputText(ParserOutput, array) #10 /srv/mediawiki/php-master/includes/page/Article.php(844): OutputPage->addParserOutput(ParserOutput, array) #11 /srv/mediawiki/php-master/includes/actions/ViewAction.php(74): Article->view() #12 /srv/mediawiki/php-master/includes/MediaWiki.php(530): ViewAction->show() #13 /srv/mediawiki/php-master/includes/MediaWiki.php(316): MediaWiki->performAction(Article, Title) #14 /srv/mediawiki/php-master/includes/MediaWiki.php(943): MediaWiki->performRequest() #15 /srv/mediawiki/php-master/includes/MediaWiki.php(546): MediaWiki->main() #16 /srv/mediawiki/php-master/index.php(53): MediaWiki->run() #17 /srv/mediawiki/php-master/index.php(46): wfIndexMain() #18 /srv/mediawiki/w/index.php(3): require(string) #19 {main}