Comment 8 for bug 1823778

Accidentally I found one reason why the Serbian language is hidden in the gnome-control-center GUI. In the add_all_languages() function in panels/common/cc-language-chooser.c the upstream code includes a call for gnome_get_all_locales(). That call is replaced by a call for gnome_get_all_languages() via ubuntu-region-langpack-install.patch. So I have submitted a MP where I propose that we simply disable ubuntu-region-langpack-install.patch for now (that feature for installing languages doesn't work anyway).

I think that the underlying reason why disabling that patch makes a difference is that the Serbian locale names according to /usr/share/i18n/SUPPORTED do not include the ".UTF-8" part. However, the alias "sr_RS.UTF-8" should really be considered valid.

With that patch disabled, two Serbian options show up in gnome-control-center. The bad news is that both refer to Serbian (Serbia), i.e. the sr_RS.UTF-8 locale, so you still can't choose the latin option (the sr_RS.UTF-8@latin locale) from gnome-control-center. (You can choose it from Language Support.)

Further investigation needed. The remaining problem is most likely related to the fact that Serbian-Latin (just as Catalan-Valencia) is represented by a locale with a locale modifier.