1649265 - Embedded Twitch Chat not loading

Status: RESOLVED FIXED

(Core :: Privacy: Anti-Tracking, defect, P1)

Description

[Gian-Carlo Pascutto [:gcp]]

It took a few days to realize I wasn't seeing bug 1645435 but this is now also broken in non-Fission mode. Bisected this to:

Bug 1628486 - Enable Dynamic First-Party Isolation in Nightly; r=ewright

STR:

1. Load https://tcec-chess.com/

Expected:
Twitch Chat window on the right

Actual:
"Failed to load module."

Comment 1

[Gian-Carlo Pascutto [:gcp]]

Confirmed that network.cookie.cookieBehavior=4 fixes it.

Comment 2

[Steven Englehardt [:englehardt]]

I can reproduce the breakage. Disabling ETP fixes it. From some quick testing this seems to be caused by https://static.twitchcdn.net/assets/minimal-608d1e6e9882757068ce.js loaded within the iframe https://www.twitch.tv/embed/TCEC_Chess_TV/chat?parent=tcec-chess.com. Specifically, when dFPI is enabled the following access to localStorage.getItem will throw NS_ERROR_FAILURE:

    try {
      var s = localStorage.getItem(this.config.forceMinConsoleLogLevelKey);
      null !== s && (o = Number(s))
    } catch (e) {
      console.error('Failed to get log level override from local storage.', {
        err: e,
        key: this.config.forceMinConsoleLogLevelKey
      })
    }

The localStorage object itself is still accessible and the key value doesn't seem to matter. I suspect this is a bug in our partitioning implementation. Gary would you mind to take a look?

Comment 3

[Gary Chen [:xeonchen]]

(In reply to Steven Englehardt [:englehardt] from comment #2)

I can reproduce the breakage. Disabling ETP fixes it. From some quick testing this seems to be caused by https://static.twitchcdn.net/assets/minimal-608d1e6e9882757068ce.js loaded within the iframe https://www.twitch.tv/embed/TCEC_Chess_TV/chat?parent=tcec-chess.com. Specifically, when dFPI is enabled the following access to localStorage.getItem will throw NS_ERROR_FAILURE:

    try {
      var s = localStorage.getItem(this.config.forceMinConsoleLogLevelKey);
      null !== s && (o = Number(s))
    } catch (e) {
      console.error('Failed to get log level override from local storage.', {
        err: e,
        key: this.config.forceMinConsoleLogLevelKey
      })
    }

The localStorage object itself is still accessible and the key value doesn't seem to matter. I suspect this is a bug in our partitioning implementation. Gary would you mind to take a look?

Thanks for your investigation!

Comment 4

[Gary Chen [:xeonchen]]

Attachment: Bug 1649265 - Document::SetDomain should apply to all principals;

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/375b436ab281
Document::SetDomain should apply to all principals; r=baku

Comment 6

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/375b436ab281