https://bugs.winehq.org/show_bug.cgi?id=41797
--- Comment #6 from Rafał Mużyło galtgendo@o2.pl --- @comment 5: well, the apps in question most likely are non-unicode, yet the question remains why the values in question aren't getting reset by LANG, despite that other are.
I would WONTFIX it too early, perhaps it's time to tinker a bit more at wine locale handling; after all it's not the only locale dependent problem (you do recall string collation should be - but currently isn't - locale dependent ?)