1764920 - The Language drop-down from the Settings page is empty after selecting the English (US) language of the Operating System via the Onboarding panel

Status: VERIFIED FIXED

(Firefox :: Messaging System, defect, P2)

Description

[Carmen Fat [:cfat] - Ecosystem QA]

[Affected versions]:

• Firefox Beta 100.0b6, Build ID: 20220414190112
• Firefox Beta 100.0b5, Build ID: 20220412185818

[Affected platforms]:

• Windows 10 x64
• Ubuntu 20.04 x64
• Linux Mint 20.2
• macOS 10.15.6, 12.3.1

[Prerequisites]:

• Have one of the latest Nightly 101 or Beta 100 installed (any of the non-en-* builds).
• Have the Operating System language set to English (US).

[Steps to reproduce]:

1. Open the browser with the profile from prerequisites.
2. Click the “Not now" button from the first slide of the Onboarding panel.
3. Click the “English (US)” button from the “Choose your language” slide.
4. Navigate to the about:preferences page.
5. Observe the Language drop-down.

[Expected result]:

• The “English (US)” string is displayed inside the Language drop-down.

[Actual result]:

• There is no string written inside the Language drop-down.

[Notes]:

• We reproduced this issue using the following Firefox localized builds: it, de, pt-PT es-ES, ru.
• Also, when reproducing the issue, the English (US) language pack is not downloaded and installed in the about:addons page.
• This issue is not reproducible when the OS is set to the following languages: Romanian, Portuguese, French, English (Ca).
• Here is a screen recording with the issue.

Comment 1

[Carmen Fat [:cfat] - Ecosystem QA]

@Greg, can you please let us know your input about this issue? Thank you.

Comment 2

[Greg Tatum [:gregtatum]]

This is happening because "en-US" is in the list of Services.locale.availableLocales, as it's included in the build, but about:preference doesn't know about the situation where you switch to "en-US" via Services.locales.requestedLocales = ["en-US"] without installing the langpack. This is a valid configuration, as far as I can tell, so this is a bug in about:preferences.

[Steps to reproduce, via browser console]:

1. Get a clean non-"en-US" build.
2. Enable the browser console.
3. Confirm that Services.locale.availableLocales contains "en-US".
4. Enter "Services.locale.requestedLocales = ["en-US"]
5. Load about:preferences

[Expected result]:

• The “English (US)” string is displayed inside the Language drop-down.

[Actual result]:

• There is no string written inside the Language drop-down.

Comment 3

[Greg Tatum [:gregtatum]]

I agree with the S3, as you could switch back to (for example) "it", then download the langpack via the normal mechanism to switch back to "en", so a workaround exists.

Comment 4

[Greg Tatum [:gregtatum]]

Actually, this appears to be a bug in about:welcome: https://bugzilla.mozilla.org/show_bug.cgi?id=1506102

Comment 5

[Greg Tatum [:gregtatum]]

Attachment: Bug 1764920 - Install the langpack even if it is the fallback; r?#platform-i18n-reviewers!

The fallback locale is not guaranteed to have all of the strings for
non-fluent files, even if it is one of the available locales. This patch
shares the logic with about:preferences for getting the available
locales.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/75252b73b233
Install the langpack even if it is the fallback; r=platform-i18n-reviewers,preferences-reviewers,mstriemer,dminor

Comment 7

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/75252b73b233

Comment 8

[Carmen Fat [:cfat] - Ecosystem QA]

• I have verified this issue on the latest Nightly 101.0a1 (Build ID: 20220429094842) on Windows 10 x64, macOS 11.6.5 and Linux Ubuntu 20.04 x64.
• The Language drop down from Settings page contains the OS language string.
  Please note that while verifying this issue, I encountered another known issue that affects Nightly: even though the OS language is set to English (US), Nightly displays English (CA) instead (I will update the comment with the link to that issue as soon as I find it; l.e: it seems that there is no bug logged for the (CA) issue, however, there was a discussion on slack about it).