1-open the content translation tool
2-start a translation (any article and any language pair
3-try to change the language of the page on the top-right ULS icon
- we can change the language
- nothing happens
- no JS errors on the console
This happens when $wgULSPosition = 'interlanguage';. ULS works fine if $wgULSPosition = 'personal'; (which is not the case on Wikipedias).
This has been broken since rMW036cde7a04c0: resourceloader: Move site-level mw.config from startup to mediawiki.base (since February).
Acknowledging that there is tech debt and changing the value of $wgULSPosition (PHP) in other extension is not a good way to do it.
Affected projects: All Wikipedias
Pre-deployment: Test on CX-testing instance, ensure it has `$wgULSPosition = 'interlanguage';, test Special:CXStats and Special:CX dashboard and translation view. Language selector should open.
Post-deployment: Same in production.
Users are able to change interface language again when using content translation.