Quiz.php on line 258
Closed, ResolvedPublicPRODUCTION ERROR
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Assigned To

Authored By

	• LarsWirzenius
	Apr 29 2020, 1:12 PM

Description

Error

MediaWiki version: 1.35.0-wmf.30

message

Argument 1 passed to Parser::fetchTemplateAndTitle() must be an instance of Title, null given, called in /srv/mediawiki/php-1.35.0-wmf.30/extensions/Quiz/includes/Quiz.php on line 258

Impact

Started happening after promoting train to group1, but not initially enough to raise deployer concerns that it warranted blocking train. Conversation in the weekly Train Log Triage session led to the conclusion that it would likely break all quizzes once they fall out of cache, so now treating as a blocker.

Details

Request ID: Xql8xwpAMNAAAsAnCN0AAAAE
Request URL: https://it.wikiversity.org/wiki/Apparato_respiratorio_(scuola_media)

Stack Trace

exception.trace

#0 /srv/mediawiki/php-1.35.0-wmf.30/extensions/Quiz/includes/Quiz.php(258): Parser->fetchTemplateAndTitle(NULL)
#1 [internal function]: Quiz->parseInclude(array)
#2 /srv/mediawiki/php-1.35.0-wmf.30/extensions/Quiz/includes/Quiz.php(245): preg_replace_callback(string, array, string)
#3 /srv/mediawiki/php-1.35.0-wmf.30/extensions/Quiz/includes/Quiz.php(205): Quiz->parseIncludes(string)
#4 /srv/mediawiki/php-1.35.0-wmf.30/extensions/Quiz/includes/QuizHooks.php(28): Quiz->parseQuiz(string)
#5 /srv/mediawiki/php-1.35.0-wmf.30/includes/parser/Parser.php(3858): QuizHooks::renderQuiz(string, array, Parser, PPFrame_Hash)
#6 /srv/mediawiki/php-1.35.0-wmf.30/includes/parser/PPFrame_Hash.php(327): Parser->extensionSubstitution(array, PPFrame_Hash)
#7 /srv/mediawiki/php-1.35.0-wmf.30/includes/parser/Parser.php(2866): PPFrame_Hash->expand(PPNode_Hash_Tree, integer)
#8 /srv/mediawiki/php-1.35.0-wmf.30/includes/parser/Parser.php(1552): Parser->replaceVariables(string)
#9 /srv/mediawiki/php-1.35.0-wmf.30/includes/parser/Parser.php(639): Parser->internalParse(string)
#10 /srv/mediawiki/php-1.35.0-wmf.30/includes/content/WikitextContent.php(368): Parser->parse(string, Title, ParserOptions, boolean, boolean, integer)
#11 /srv/mediawiki/php-1.35.0-wmf.30/includes/content/AbstractContent.php(565): WikitextContent->fillParserOutput(Title, integer, ParserOptions, boolean, ParserOutput)
#12 /srv/mediawiki/php-1.35.0-wmf.30/includes/Revision/RenderedRevision.php(267): AbstractContent->getParserOutput(Title, integer, ParserOptions, boolean)
#13 /srv/mediawiki/php-1.35.0-wmf.30/includes/Revision/RenderedRevision.php(236): MediaWiki\Revision\RenderedRevision->getSlotParserOutputUncached(WikitextContent, boolean)
#14 /srv/mediawiki/php-1.35.0-wmf.30/includes/Revision/RevisionRenderer.php(215): MediaWiki\Revision\RenderedRevision->getSlotParserOutput(string)
#15 /srv/mediawiki/php-1.35.0-wmf.30/includes/Revision/RevisionRenderer.php(152): MediaWiki\Revision\RevisionRenderer->combineSlotOutput(MediaWiki\Revision\RenderedRevision, array)
#16 [internal function]: MediaWiki\Revision\RevisionRenderer->MediaWiki\Revision\{closure}(MediaWiki\Revision\RenderedRevision, array)
#17 /srv/mediawiki/php-1.35.0-wmf.30/includes/Revision/RenderedRevision.php(198): call_user_func(Closure, MediaWiki\Revision\RenderedRevision, array)
#18 /srv/mediawiki/php-1.35.0-wmf.30/includes/poolcounter/PoolWorkArticleView.php(204): MediaWiki\Revision\RenderedRevision->getRevisionParserOutput()
#19 /srv/mediawiki/php-1.35.0-wmf.30/includes/poolcounter/PoolCounterWork.php(128): PoolWorkArticleView->doWork()
#20 /srv/mediawiki/php-1.35.0-wmf.30/includes/page/Article.php(796): PoolCounterWork->execute()
#21 /srv/mediawiki/php-1.35.0-wmf.30/includes/actions/ViewAction.php(66): Article->view()
#22 /srv/mediawiki/php-1.35.0-wmf.30/includes/MediaWiki.php(519): ViewAction->show()
#23 /srv/mediawiki/php-1.35.0-wmf.30/includes/MediaWiki.php(305): MediaWiki->performAction(Article, Title)
#24 /srv/mediawiki/php-1.35.0-wmf.30/includes/MediaWiki.php(973): MediaWiki->performRequest()
#25 /srv/mediawiki/php-1.35.0-wmf.30/includes/MediaWiki.php(535): MediaWiki->main()
#26 /srv/mediawiki/php-1.35.0-wmf.30/index.php(47): MediaWiki->run()
#27 /srv/mediawiki/w/index.php(3): require(string)
#28 {main}

	Subject	Repo	Branch	Lines +/-
	Don't crash if quiz attempts to include a bad title	mediawiki/extensions/Quiz	wmf/1.35.0-wmf.30	+4 -0
	Don't crash if quiz attempts to include a bad title	mediawiki/extensions/Quiz	master	+4 -0

Customize query in gerrit

Related Objects
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		Status	Subtype	Assigned	Task
		Resolved	Release	brennen	T249962 1.35.0-wmf.30 deployment blockers
		Resolved	PRODUCTION ERROR	cscott	T251409 Argument 1 passed to Parser::fetchTemplateAndTitle() must be an instance of Title, null given, called in /srv/mediawiki/php-1.35.0-wmf.30/extensions/Quiz/includes/Quiz.php on line 258

Event Timeline

• LarsWirzenius created this task.Apr 29 2020, 1:12 PM

Restricted Application added a subscriber: Aklapper. · View Herald TranscriptApr 29 2020, 1:12 PM

DannyS712 added a project: MediaWiki-extensions-Quiz.Apr 29 2020, 1:21 PM

I notice 07cccb66 touches fetchTemplateAndTitle() - @cscott, any thoughts on this one?

diff --git a/includes/Quiz.php b/includes/Quiz.php
index 0866bf9..61c1765 100644
--- a/includes/Quiz.php
+++ b/includes/Quiz.php
@@ -255,7 +255,7 @@ class Quiz {
         */
        private function parseInclude( $matches ) {
                $title = Title::makeTitleSafe( NS_MAIN, $matches[1] );
-               $text = $this->mParser->fetchTemplate( $title );
+               $text = $this->mParser->fetchTemplateAndTitle( $title )[0];
                $output = '';
                if ( preg_match( '`<quiz[^>]*>(.*?)</quiz>`sU', $text, $unparsedQuiz ) ) {
                        // Remove inclusions from included quiz.

brennen moved this task from Backlog to Logs/Train on the User-brennen board.Apr 29 2020, 4:30 PM

brennen added a parent task: T249962: 1.35.0-wmf.30 deployment blockers.Apr 29 2020, 6:05 PM

This is a train blocker now.

Restricted Application added a subscriber: Liuxinyu970226. · View Herald TranscriptApr 29 2020, 6:06 PM

Per conversation in Train Log Triage meeting, marking blocker and tentatively assigning to cscott.

Krinkle moved this task from Untriaged to Apr 2020 on the Wikimedia-production-error board.Apr 29 2020, 6:07 PM

brennen updated the task description. (Show Details)Apr 29 2020, 7:10 PM

Aklapper merged a task: T251454: Diff shows TypeErro: Argument 1 passed to Parser::fetchTemplateAndTitle() must be an instance of Title, null given, called in /srv/mediawiki/php-1.35.0-wmf.30/extensions/Quiz/includes/Quiz.php on line 258.Apr 29 2020, 7:35 PM

Aklapper added a subscriber: Samuele2002.

In T251409#6094189, @brennen wrote:

I notice 07cccb66 touches fetchTemplateAndTitle() - @cscott, any thoughts on this one?

This patch was merged Jan 29 ( https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Quiz/+/568158 ) though and presumably deployed in Feb? So, my guess is something else changed that is triggering this. I'll peek at the Parser briefly, but I imagine @cscott might be able to tell what is going on here better.

I don't think 25f3b8ad68acbc2ce18b1c836e0355178d5afc82 / 07cccb6666eafe39efb629c051cfb3669b8f072d is actually responsible, since the definition of Parser::fetchTemplate() in core is:

	public function fetchTemplate( Title $title ) {
		wfDeprecated( __METHOD__, '1.35' );
		return $this->fetchTemplateAndTitle( $title )[0];
	}

aka, doing the exact same thing. But probably whatever patch added the Title type declaration to fetchTemplate (and probably to fetchTemplateAndTitle at the same time) is the actual culprit. ~~I guess maybe Quiz had a template callback registered that replaced the null Title with a 'real' one?~~ I'll keep this one assigned to me and get a patch working regardless...

https://github.com/wikimedia/mediawiki/blob/master/includes/parser/Parser.php#L3531-L3534 indicates the change to Quiz is legitimate ... the proxying from fetchTemplate -> fetchTemplateAndTitle in Parser.php just got inlined into the Quiz extension.

The actual culprit appears to be 99104944e884754fd39a3aabc55f721dbe322d54 by @Fomafix, but I C+2'ed it so I'm still on the hook. It was included first in 1.35.0-wmf.30.

This is the relevant code in Quiz:

	private function parseInclude( $matches ) {
		$title = Title::makeTitleSafe( NS_MAIN, $matches[1] );
		$text = $this->mParser->fetchTemplateAndTitle( $title )[0];
		$output = '';

The only time Title::makeTitleSafe returns null is if there's an error, like an invalid namespace or malformed Title. So this is only likely to be an issue on a page where the quiz is already broken, that is, has a bad inclusion. On the request URL mentioned above, the issue is {{ip|wikt}}, and ip|wikt is not a valid title.

That's just to inform the severity discussions. I don't think this will "break all quizes" as they fall out of cache. (But a patch won't be hard anyway and I'll have one in a few minutes, so the severity discussion is probably moot.)

Change 593318 had a related patch set uploaded (by C. Scott Ananian; owner: C. Scott Ananian):
[mediawiki/extensions/Quiz@master] Don't crash if quiz attempts to include a bad title

https://gerrit.wikimedia.org/r/593318

gerritbot added a project: Patch-For-Review.Apr 29 2020, 9:02 PM

Change 593318 merged by jenkins-bot:
[mediawiki/extensions/Quiz@master] Don't crash if quiz attempts to include a bad title

https://gerrit.wikimedia.org/r/593318

Change 593319 had a related patch set uploaded (by Jforrester; owner: C. Scott Ananian):
[mediawiki/extensions/Quiz@wmf/1.35.0-wmf.30] Don't crash if quiz attempts to include a bad title

https://gerrit.wikimedia.org/r/593319

cscott mentioned this in T249962: 1.35.0-wmf.30 deployment blockers.Apr 29 2020, 9:12 PM

Change 593319 merged by jenkins-bot:
[mediawiki/extensions/Quiz@wmf/1.35.0-wmf.30] Don't crash if quiz attempts to include a bad title

https://gerrit.wikimedia.org/r/593319

Mentioned in SAL (#wikimedia-operations) [2020-04-29T21:17:01Z] <jforrester@deploy1001> Synchronized php-1.35.0-wmf.30/extensions/Quiz/includes/Quiz.php: Don't crash if quiz attempts to include a bad title T251409 (duration: 01m 06s)

Deployed and confirmed.

The only time Title::makeTitleSafe returns null is if there's an error, like an invalid namespace or malformed Title. So this is only likely to be an issue on a page where the quiz is already broken, that is, has a bad inclusion. On the request URL mentioned above, the issue is {{ip|wikt}}, and ip|wikt is not a valid title.

Makes sense - so probably wouldn't have been too substantial an impact after all. Thanks much for the quick turnaround, nonetheless.

ReleaseTaggerBot added a project: MW-1.35-notes (1.35.0-wmf.31; 2020-05-05).Apr 29 2020, 10:00 PM

thiemowmde awarded a token.Apr 30 2020, 6:26 AM

Argument 1 passed to Parser::fetchTemplateAndTitle() must be an instance of Title, null given, called in /srv/mediawiki/php-1.35.0-wmf.30/extensions/Quiz/includes/Quiz.php on line 258Closed, ResolvedPublicPRODUCTION ERRORActions