Some sites set site-specific JS/CSS in MediaWiki:Common.js / MediaWiki:Common.css which will need updates when output is changed.
Ex: https://ar.wikipedia.org/wiki/%D9%85%D9%8A%D8%AF%D9%8A%D8%A7%D9%88%D9%8A%D9%83%D9%8A:Common.css
Also see https://github.com/wikimedia/integration-visualdiff/blob/master/lib/parsoid.custom_styles.yaml for some mods around this.
This may need some upfront communication to update before rolling out on those wikis with custom mods.
---
From T271114#8350994,
A common styling that wikis have is a minimum width for a thumb.
```
/* Minimum thumb width */
.thumbinner {
min-width: 100px;
}
```
A suggested edit to preserve that looks like,
https://it.wikipedia.org/w/index.php?title=MediaWiki%3ACommon.css&type=revision&diff=130152006&oldid=127986303
Though that doesn't exactly account for padding, as in the following, if you wanted pixel diff matching,
https://github.com/wikimedia/integration-visualdiff/blob/a65bef82fd9247d58b11a2e28eae7636ee32c67d/lib/parsoid.custom_styles.yaml#L475-L484
Two queries to surface wikis that would need updating are:
* P38161 - `mwgrep --title "Common.css" "Minimum thumb width"`
* P38162 - More generally, `mwgrep --title "Common.css" "thumbinner"`
---
From T271114#8351603,
A common template that wikis have implemented is for a series of images. The images are selected to be stepped through based on a class which is no longer emitted,
```
var $images = $( imageGroupUnits ).children( '.center' );
```
A suggested edit to preserve the functionality is,
https://it.wikipedia.org/w/index.php?title=MediaWiki%3ACommon.js&type=revision&diff=130157033&oldid=127743689
A query to surface wikis that would need updating is:
* P38163 - `mwgrep --title "Common.js" "ImageGroup"`