PHP Notice: Trying to get property 'nextSibling' of non-object
Closed, ResolvedPublicPRODUCTION ERROR
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Authored By

	thcipriani
	Oct 20 2022, 3:17 PM

Description

Error

mwversion: 1.40.0-wmf.6
reqId: b9a9d517-1253-4ba9-b930-fccced062f7a
Find reqId in Logstash

normalized_message

[{reqId}] {exception_url}   PHP Notice: Trying to get property 'nextSibling' of non-object

exception.trace

from /srv/mediawiki/php-1.40.0-wmf.6/extensions/DiscussionTools/includes/ApiDiscussionToolsPageInfo.php(185)
#0 /srv/mediawiki/php-1.40.0-wmf.6/extensions/DiscussionTools/includes/ApiDiscussionToolsPageInfo.php(185): MWExceptionHandler::handleError(integer, string, string, integer, array)
#1 /srv/mediawiki/php-1.40.0-wmf.6/extensions/DiscussionTools/includes/ApiDiscussionToolsPageInfo.php(90): MediaWiki\Extension\DiscussionTools\ApiDiscussionToolsPageInfo::getThreadItemsHtml(MediaWiki\Extension\DiscussionTools\ContentThreadItemSet)
#2 /srv/mediawiki/php-1.40.0-wmf.6/includes/api/ApiMain.php(1900): MediaWiki\Extension\DiscussionTools\ApiDiscussionToolsPageInfo->execute()
#3 /srv/mediawiki/php-1.40.0-wmf.6/includes/api/ApiMain.php(875): ApiMain->executeAction()
#4 /srv/mediawiki/php-1.40.0-wmf.6/includes/api/ApiMain.php(846): ApiMain->executeActionWithErrorHandling()
#5 /srv/mediawiki/php-1.40.0-wmf.6/api.php(90): ApiMain->execute()
#6 /srv/mediawiki/php-1.40.0-wmf.6/api.php(45): wfApiMain()
#7 /srv/mediawiki/w/api.php(3): require(string)
#8 {main}

Notes

happens about 3× per day
only on wikipedia wikis and mw.org in the last 30 days
certain GET requests to the API seem to cause it

Details

Request URL: https://sr.wikipedia.org/w/api.php?action=discussiontoolspageinfo&errorformat=*&errorsuselocal=*&format=*&formatversion=*&page=*&prop=*

Related Changes in Gerrit:

	Subject	Repo	Branch	Lines +/-
	Avoid error building threaditemshtml if there's an empty final section	mediawiki/extensions/DiscussionTools	master	+16 -3

Customize query in gerrit

Related Objects

Mentioned In: T325575: "Trying to get property 'nextSibling' of non-object" in AnnotationDOMRangeBuilder.php
Mentioned Here: T325575: "Trying to get property 'nextSibling' of non-object" in AnnotationDOMRangeBuilder.php

Event Timeline

thcipriani created this task.Oct 20 2022, 3:17 PM

Restricted Application added a subscriber: Aklapper. · View Herald TranscriptOct 20 2022, 3:17 PM

ppelberg moved this task from Backlog to Triaged on the DiscussionTools board.Oct 20 2022, 3:18 PM

ppelberg moved this task from Untriaged to Upcoming on the Editing-team board.

Definitely one that'd be easier to debug if we had the exact page it's being called on.

That said, it's happening on a heading:

$startNode = CommentUtils::closestElementWithSibling( $startRange->endContainer, 'next' );
$startNode = $startNode->nextSibling;

So I'd speculate: a page on which the very last element is a heading.

In T321317#8332806, @DLynch wrote:

Definitely one that'd be easier to debug if we had the exact page it's being called on.

Check out the link in logstash you can expand the document there and see the exact request (we try to avoid exact links on error tasks for privacy reasons).

@thcipriani Ah, good point, thank you.

So here's a page which exhibits the issue: https://sr.wikipedia.org/wiki/%D0%A0%D0%B0%D0%B7%D0%B3%D0%BE%D0%B2%D0%BE%D1%80%3A%D0%A1%D0%B2%D0%B5%D1%82%D0%BB%D0%B0%D0%BD%D0%B0_%D0%A0%D0%B0%D0%B6%D0%BD%D0%B0%D1%82%D0%BE%D0%B2%D0%B8%D1%9B

It does indeed end with a section that only contains a heading. I can write a patch to make this a bit more robust.

matmarex edited projects, added Editing-team (Kanban Board); removed Editing-team.Oct 20 2022, 7:44 PM

DLynch moved this task from Inbox to Doing on the Editing-team (Kanban Board) board.Nov 29 2022, 6:29 PM

Change 863012 had a related patch set uploaded (by DLynch; author: DLynch):

[mediawiki/extensions/DiscussionTools@master] Avoid error building threaditemshtml if there's an empty final section

https://gerrit.wikimedia.org/r/863012

gerritbot added a project: Patch-For-Review.Dec 1 2022, 5:44 PM

DLynch moved this task from Doing to Code Review on the Editing-team (Kanban Board) board.Dec 1 2022, 5:44 PM

Change 863012 merged by jenkins-bot:

[mediawiki/extensions/DiscussionTools@master] Avoid error building threaditemshtml if there's an empty final section

https://gerrit.wikimedia.org/r/863012

ReleaseTaggerBot added a project: MW-1.40-notes (1.40.0-wmf.13; 2022-12-05).Dec 1 2022, 9:00 PM

Maintenance_bot removed a project: Patch-For-Review.Dec 1 2022, 9:30 PM

Check logs after the deployment to confirm: https://logstash.wikimedia.org/goto/a565d7eca62bcf6dcb646f4ada921da7

DLynch claimed this task.Dec 5 2022, 6:14 PM

ppelberg reassigned this task from DLynch to matmarex.Dec 19 2022, 6:29 PM

matmarex mentioned this in T325575: "Trying to get property 'nextSibling' of non-object" in AnnotationDOMRangeBuilder.php.Dec 19 2022, 7:22 PM

Looks fixed: https://logstash.wikimedia.org/goto/2f999b0e49ff2ca825f1f2f9a1cd169c

In the query I linked previously: https://logstash.wikimedia.org/goto/a565d7eca62bcf6dcb646f4ada921da7, there are other recent errors, but these are actually a different issue with the same error message, which I filed as T325575.

ppelberg closed this task as Resolved.Dec 22 2022, 1:20 AM

	F35876856: image.png
	Dec 19 2022, 7:24 PM

PHP Notice: Trying to get property 'nextSibling' of non-objectClosed, ResolvedPublicPRODUCTION ERRORActions