2052932 - `emulation.setLocaleOverride` does not override `Accept-Language` header for in `Worker` for `fetch` and `WebSocket`

Status: RESOLVED FIXED

(Remote Protocol :: WebDriver BiDi, defect, P3)

Description

[Devin Rousso]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/150.0.0.0 Safari/537.36 Edg/150.0.0.0

Steps to reproduce:

1. navigate a top-level context to a page
2. emulation.setLocaleOverride { locale: "de-DE", contexts: [<context>] }
3. in the page, create a Worker with one/both of:
   • fetch("/echo-accept-language")
   • new WebSocket("ws://.../echo")
4. for comparison, issue the same fetch and WebSocket from the document itself

Actual results:

document fetch and WebSocket handshake have Accept-Language: de-DE

Worker fetch and WebSocket have default Accept-Language

Expected results:

Worker fetch and WebSocket handshakes send Accept-Language: de-DE, matching document requests and matching the JS locale that bug 2015655 already emulates in Worker

Comment 1

[Devin Rousso]

Attachment: Bug 2052932 - [webdriver-bidi] `emulation.setLocaleOverride` does not override `Accept-Language` header for in `Worker` for `fetch` and `WebSocket`

Bug 1995691 made emulation.setLocaleOverride override the Accept-Language request header, but only for document-initiated requests.
Bug 2015655 made the locale override apply to the JS realm and navigator.language in Worker and SharedWorker but it did not touch the Accept-Language header or WebSocket path.

HttpBaseChannel::Init builds Accept-Language from mLoadInfo->GetBrowsingContext()->Top()->GetLanguageOverride().
For Worker requests GetBrowsingContext() is null, and the code never consults GetAssociatedBrowsingContext(), which fetch() already populates on the channel's LoadInfo.

Worker WebSocket handshakes are additionally missing that association as the channel's LoadInfo never gets associatedBrowsingContextID set at all.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/a0439072852c
https://hg.mozilla.org/integration/autoland/rev/2fa94676a276
[webdriver-bidi] `emulation.setLocaleOverride` does not override `Accept-Language` header for in `Worker` for `fetch` and `WebSocket` r=necko-reviewers,kershaw,jdescottes,whimboo

Comment 3

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/61276 for changes under testing/web-platform/tests

Comment 4

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/2fa94676a276

Comment 5

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream PR merged by moz-wptsync-bot