Incorrect language redirection in addons.mozilla.org

[yookoala]

Describe the problem and steps to reproduce it:

Website should follow browser's language priority when doing redirection / content detection. The "Accepted-Language" header include priority for the language in it. All redirection or locale detection should respect the priority specified there.

For example, when provided with this "Accepted-Language" header:

zh-HK,zh-TW;q=0.8,en-US;q=0.5,en;q=0.3"

a website should:

1. find "zh-HK" (Traditional Chinese, Hong Kong) and "zh-TW" (Traditional Chinese, Taiwan) first. If exists, redirect / show the content in that language.
2. If not exists, find "en-US". redirect / show the content in that language.
3. If not exists, find "en". redirect / show the content in that language.

What happened?

If you supply a request to addons.mozilla.org/firefox with the said header:

zh-HK,zh-TW;q=0.8,en-US;q=0.5,en;q=0.3"

it will redirect you to addons.mozilla.org/zh-CN/firefox.

What did you expect to happen?

That is not an expected response. It is wrong in multiple levels:

1. Even there is no "zh-HK" in the site, there is "zh-TW". From language priority, it should be shown.
2. "zh-CN" is never a part of the language preference. If should not be shown, or it should be shown as a fallback only if both "zh-HK" and "zh-TW" are absent.
3. Event without language priority to "zh-TW", the fallback to "zh-HK" should always be "zh-TW" (both Traditional Chinese).

[eviljeff]

What's happening is we have fallback code that takes an unsupported long code (zh-HK) and converts it into a short code (zh) which then converts to the default for that short code (zh-CN). Then, because a locale has been 'found', it ignores the subsequent locale codes in the accept header. (It can also be replicated with pt-XX,pt-BR which redirects to pt-PT instead)

For zh-* see #4515 also

[yookoala]

Is there anyway to override this redirection? The fallback of zh-HK or zh-Hant-HK should have been zh-Hant (if made available in 7d82b59, mozilla/addons-server#5811).

[eviljeff]

In the end zh-Hant wasn't made available in mozilla/addons-server#5811, as #4515 mentions.

There isn't a way to override the redirection, we need to fix the logic. In the meantime you can visit https://addons.mozilla.org/zh-TW/firefox directly.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. If you think this bug should stay open, please comment on the issue with further details. Thank you for your contributions.

[yookoala]

The issue is still not fixed. Please re-open this issue.