Last modified: 2014-11-07 18:26:30 UTC
On en.wiki, go to https://en.m.wikipedia.org/wiki/Main_Page?uselang=fr. Enter a nonsense search term like "sdghyth". The message "Search within pages to see if this phrase appears anywhere" will be in English instead of French. Strangely, I can reproduce this everywhere except locally, including on Beta Labs. My core and extensions are completely up to date though.
Prioritization and scheduling of this bug is tracked on Trello card https://trello.com/c/lqjSdb8G
This will be an issue with Mantle In Mantle in the ResourceLoaderParsedMessageModule any message that is followed by a 'parse' parameter and parsed before shipped to the client. The language parameter is passed to the ResourceLoader module wfMessage( $key )->parse(); Doesn't take into account the language of the context.
Only applies when uselang query string parameter is used so not a huge deal..
This applies to anyone who's user language doesn't match the content language, which is quite common.