This is happening in safe mode as well. See https://en.wikipedia.org/wiki/Wikipedia:Catalogue_of_CSS_classes?useskin=vector-2022&safemode=1

This started on 27 January 2023 (UTC time).

I believe that it happens only with "limited width mode" disabled, while logged in. Safe mode apparently does not use default preferences. I can replicate it in Firefox and Brave for Mac OS.

Related to T327886: Long string of characters comes out of the body content and overlaps the Article tools menu in Vector 2022 and other related tasks there.

This is a somewhat urgent problem. I have found that it is affecting between 1 in 20 and 1 in 10 pages that I visit. The scroll width is up to 10x the width of my browser window.

Contrary to my earlier hypothesis, I am able to make this happen on a few pages with limited width mode enabled. It happens much less often, though, FWIW.

I have wondered for a while why it is a good idea to install software changes on Friday, right before all of the developers take two days off. Wikipedia is a 24/7 web site. It seems like there should at least be someone who looks at these bug reports seven days a week to see if anything major has been broken, especially when there are frequent updates to a new beta product that the developers presumably want to perform very well.

I concur with Jonesey95, Wikipedia is a 24/7 site. If you want to add updates, do it on Mon-Wed, or have at least one person capable of rolling back things on weekends if they are not working as intended. Alternatively, just roll back Vector 2022 entirely, and come back when you're done dealing with all these miserable bugs.

I can reproduce it in diff when logged in, using Firefox both with the toggle on and off.

Using Chrome only with the limited width selected via the toggle.

This is another instance of https://www.mediawiki.org/wiki/Recommendations_for_mobile_friendly_articles_on_Wikimedia_wikis which has long been an issue for mobile users, and one of the main sources of friction for making Wikipedia truly a responsive design. With the fixed width it is now showing up on Vector 2022 skins.

To be clear there is no magic fix here - please notice the bug shows up on Minerva and Timeless (when JavaScript and Timeless workaround is disabled).The only difference with those is they adjust as you resize the window small.

Up until now we've advised https://www.mediawiki.org/wiki/Recommendations_for_mobile_friendly_articles_on_Wikimedia_wikis#Wrap_wide_images_and_tables which is an editorial fix, which I think is preferable (we have Wide image template why not Wide table?)

I think a more brute force way of doing this would be to update the parser so tables are wrapped in divs automatically but that would be pretty disruptive change (for example it doesn't seem compatible with sticky headers - those would no longer work).

I believe this is a duplicate of T66577 . (See also https://phabricator.wikimedia.org/T66577#8567450)

The above explanation does not account for https://en.wikipedia.org/wiki/Wikipedia:Catalogue_of_CSS_classes?useskin=vector-2022&safemode=1 working reasonably when I enable limited-width mode, but being very wide when I disable limited-width mode.

I get that there is a big picture here, but that bug is from 2014. This is a different bug. This bug started happening on Friday, and it is widespread. Please roll back whatever change caused this problem on Friday.

Seems like we're mixing 2 issues here.

• The diff issue is a table issue and is described in T66577

https://en.wikipedia.org/w/index.php?title=Brahmic_scripts&diff=1135922907&oldid=1132384454&diff=&diffmode=source&useskin=vector-2022

• The https://en.wikipedia.org/wiki/Wikipedia:Catalogue_of_CSS_classes?useskin=vector-2022&safemode=1 issue is an issue with the PRE tag. I've repurposed this ticket accordingly.

I can't replicate this locally on master or the current deployment branch (yet). It seems SyntaxHighlight_GeSHi and DiscussionTools do something to this page that might be interfering but I've not been able to replicate that yet.

It's not just pre. An image with the appropriate wide image template as explicitly recommended doesn't fix the issue. I left this on another task discussing an issue in V22 but since you think it's one cause, it's not. https://en.wikipedia.org/wiki/Sixth_Amendment_to_the_United_States_Constitution?useskin=vector-2022 with limited width turned off exhibits the same issue.

@Izno right. Live debugging as we speak. I've managed to replicate it locally now. Good news is that it's an issue limited to logged in users right now. Seems to be an incompatibility between the page tools feature and the limited width toggle.

In T328196#8570783, @Jdlrobson wrote:

Seems like we're mixing 2 issues here.

• The diff issue is a table issue and is described in T66577

https://en.wikipedia.org/w/index.php?title=Brahmic_scripts&diff=1135922907&oldid=1132384454&diff=&diffmode=source&useskin=vector-2022

• The https://en.wikipedia.org/wiki/Wikipedia:Catalogue_of_CSS_classes?useskin=vector-2022&safemode=1 issue is an issue with the PRE tag. I've repurposed this ticket accordingly.

I can't replicate this locally on master or the current deployment branch (yet). It seems SyntaxHighlight_GeSHi and DiscussionTools do something to this page that might be interfering but I've not been able to replicate that yet.

Thank you @Jdlrobson for the link to the task about the diff issue. Sorry for not reporting this in the right place.