Multilanguage support in GNU/Linux patcher not work properly in some situations.
At this moment, multilanguage support in GNU/Linux patcher have three (low priority) issues:
1) Language code detection
Due to ISO specification, language codes can be 2 or 3 letters long. Current system check only for first 2 characters. It works with most language codes, but not for example with Asturian language (code: ast)
2) Country code detection
Some languages have own variants which depends on countries, for example, there is some differences between Portuguese used in Portugal (pt_PT) and in Brazil (pt_BR). Current system don't check for language codes.
3) System language detection
If default language for operating system is other than any supported by game, patcher don't find any translation and show to user untranslated, unclear system messages. Proposition for fix: if default operating system language isn't supported, patcher should fall back to English language.
I was added to issue patch which should fix this all problems (is shorter than this description, heh). If something here is unclear, please ask.