1961578 - navigator.languages is just `en-US` in Firefox on Android

Status: NEW

(Firefox for Android :: Browser Engine, defect)

Description

[Daniel Holbert [:dholbert]]

Attachment: testcase 1

STR:

1. Load attached testcase, in US-English version of Firefox for Android.

ACTUAL RESULTS:
Testcase reports an array of length 1 with contents en-US (for me at least)

EXPECTED RESULTS:
Testcase should report an array of length 2 with en-US and en as the entries.

Notes:

• Firefox Nightly on Android gives me ACTUAL RESULTS.
• Chrome on the same Android device and Firefox-on-Desktop give me EXPECTED RESULTS.
• This seems to be the cause of webcompat bug 1960835, as best as I can tell.

Comment 1

[Daniel Holbert [:dholbert]]

This value seems to be fully determined by the intl.accept_languages about:config pref.

On Desktop, it looks like that value comes from here:
https://searchfox.org/mozilla-central/rev/c3fd24fa4836680544dee8c31276bb9159a5308d/toolkit/locales/en-US/chrome/global/intl.properties#23

intl.accept_languages=en-US, en

I can see that we have the pref defaulting to that properties file path here:
https://searchfox.org/mozilla-central/rev/c3fd24fa4836680544dee8c31276bb9159a5308d/modules/libpref/init/all.js#1494

pref("intl.accept_languages",               "chrome://global/locale/intl.properties");

...and if I tap the "reset" button on Android, I can see that it resets to that^ chrome://global/locale/intl.properties value. And if I directly load chrome://global/locale/intl.properties, I can see it has intl.accept_languages=en-US, en listed inside it, on Android. Nonetheless, if I restart my browser, the about:config pref somehow gets updated to just have the value en-US.

Comment 2

[Makoto Kato [:m_kato]]

GeckoView (Firefox Android) is multi-locale package, so intl.accept_languages is updated by GeckoView API (at startup).

Comment 3

[Makoto Kato [:m_kato]]

We need to fix bug 1889845 for it, or add something normalization for it

Comment 4

[Daniel Holbert [:dholbert]]

Thanks!

Comment 5

[BugBot [:suhaib / :marco]]

The severity field is not set for this bug.
:boek, could you have a look please?

For more information, please visit BugBot documentation.

Comment 6

[Makoto Kato [:m_kato]]

https://treeherder.mozilla.org/jobs?repo=try&revision=809ae07904507d138fccba52b2aabb2181b9e5fa