Re: Language code changes over time: zh_CN -> zh_Hans

[Florian Weimer <fweimer@redhat.com>]

* Jean-Baptiste Holcroft:

> the Fedora community is migrating to the Weblate translation platform.
> This translation platform uses zh_Hans, zh_Hant, zh_Hant_HK by
> default, instead of zh_CN, zh_TW and zh_HK.

Is zh_Hant_HK perhaps a typo?  Written as-is, that's going to be
problematic.  We had some bugs specific to the eo locale because its
name does not have an underscore in it.

I'm not sure if the language tag syntax is actually compatible with our
locale names.  For example, we write sr-Latn-RS (mentioned in RFC 5646)
as sr_RS@latin.

We have an aliasing mechanism, so we don't need to store the locale data
several times over, so that part shouldn't be a problem.

> If I understand correctly, we need to make sure the language code
> exists in glibc before deciding using the new code for Linux
> applications.
>
> The issue is as follow: a translation platform can be used by many
> projects, not all using glibc, like Websites or mobile application who
> already are using the new code.
>
> The web tells that the codes zh_CN, zh_TW, zh_HK are old codes and
> should be replaced by the new ones.
> Multiple sources tends to confirm this (and show that other actors
> already did the move), the most relevant ones are:
> https://www.w3.org/TR/i18n-html-tech-lang/#h2_langvalues

This says:

| Where possible, use the codes zh-Hans and zh-Hant to refer to Simplified
| and Traditional Chinese, respectively. more...

And the “more...” link goes to:

<https://www.w3.org/International/articles/language-tags/Overview.var#script>

which is dead.  This isn't very reassuring.

> What is the support status of these new language codes in Glibc?
> If not supported, can we imagine to have backward compatibility while
> upstream projects migrate to the new language code?
> I assume these are not the only language code renaming, what policy do
> you suggest concerning these?

We must have renamed language codes in the past, but I don't remember
any examples.  Mostly we hadn't 1:1 replacements, but transitions due to
changing political circumstances.  There were also some language codes
which were completely wrong.

Thanks,
Florian