@cooltey what languages do you have set and in what order in the iOS Settings app > General > Language & Region?

@JoeWalsh, here's the screenshot of the language setting and I remember that the previous version of the Wikipedia app does not have this issue.

I've tested it with and without logging in my account and can reproduce it in both scenarios.

Change 606013 had a related patch set uploaded (by Joewalsh; owner: Joewalsh):
[mediawiki/services/mobileapps@master] Only pass the first relevant language code along to action=mobileview

https://gerrit.wikimedia.org/r/606013

Change 606013 merged by Joewalsh:
[mediawiki/services/mobileapps@master] Only pass the first relevant language code along to action=mobileview

https://gerrit.wikimedia.org/r/606013

Changed has been deployed. Please test with the native apps.

Still seeing the issue. I have set my iPad's primary language in Traditional Chinese.

The title should be looked like below:

It works when hitting mobileapps directly[1] but RESTBase[2] doesn't forward the accept-language header to it when requesting mobile-html. This doesn't even work with the summary endpoint through RB, it seems[3], but it does with mobile-sections-lead[4].

I set my browser to Traditional Chinese:
[1] http://localhost:8888/zh.wikipedia.org/v1/page/mobile-html/%E8%B4%9D%E6%8B%89%E5%85%8B%C2%B7%E5%A5%A5%E5%B7%B4%E9%A9%AC
shows 巴拉克·歐巴馬 (ok, i think)
[2] http://localhost:7233/zh.wikipedia.org/v1/page/mobile-html/%E8%B4%9D%E6%8B%89%E5%85%8B%C2%B7%E5%A5%A5%E5%B7%B4%E9%A9%AC
shows 巴拉克·奥巴马 (i know the last character is wrong) (Ignore the CSP issues there when running locally for now. It's enough to see the first section.)
[3] http://localhost:7233/zh.wikipedia.org/v1/page/summary/%E8%B4%9D%E6%8B%89%E5%85%8B%C2%B7%E5%A5%A5%E5%B7%B4%E9%A9%AC shows "displaytitle": "贝拉克·奥巴马", (i know the last character is wrong)
[4] http://localhost:7233/zh.wikipedia.org/v1/page/mobile-sections-lead/%E8%B4%9D%E6%8B%89%E5%85%8B%C2%B7%E5%A5%A5%E5%B7%B4%E9%A9%AC shows "displaytitle": "巴拉克·歐巴馬" (ok, i think)

@Pchelolo Is there anything special about Chinese language variant handling that makes it work for mobile-sections* but not for mobile-html and summary?

@Pchelolo It looks like the requests work when Accept-Language contains a single language with a Wikipedia language code. For example Accept-Language: en, zh-tw;q=0.5 doesn't work but Accept-Language: zh-tw does. The former is what the app sends currently and is the format described by ietf. The mobileapps service has logic to take the standard header and translate it to the relevant wikipedia language codes for the given request. For example, a request with Accept-Language: en, sr-Latn;q=0.9, sr-Cyrl;q=0.8 to sr.wikipedia.org is normalized to sr-el. We'd be OK with the whole header being passed on to the mobileapps service so that logic handles the request. However, if the header needs to be normalized before it gets to the mobileapps service, could that logic be used upstream?

In RESTBase we want to know if the language has variants for efficiency reasons, so the code from mobile apps should probably be upstreamed to RESTBase. Currently it's understanding of accept-language header is very basic.

In RESTBase we want to know if the language has variants for efficiency reasons, so the code from mobile apps should probably be upstreamed to RESTBase. Currently it's understanding of accept-language header is very basic.

I filed T256491 to capture this change. I thought this was working before - did RESTBase previously pass the entire Accept-Language header onto mobileapps?

I thought this was working before - did RESTBase previously pass the entire Accept-Language header onto mobileapps?

Nothing changed in that area as far as I know.. Strange.

Since we captured the issues for RESTBase in T256491, I'm going to untag our team.