1340391 - XHR on background page strips cookie if 3rd-party cookie is disabled

Status: RESOLVED DUPLICATE of bug 1322113

(WebExtensions :: Untriaged, defect)

Description

[Tim Guan-tin Chien [:timdream] (please needinfo)]

STR:

1. about:preferences#privacy > Set "Nightly will [Use custom settings for history]" and "Accept third-party cookies: [Never]"
2. Create an Web Extension add-on with permission to a specific origin that requires login and cookie, e.g. Bugzilla.
3. Try to fetch something from that site in the add-on, like

  var xhr = new XMLHttpRequest();
  xhr.responseType = 'document';
  xhr.withCredentials = true;
  xhr.open('GET', url);
  xhr.send();

Expected:

1. HTTP request is sent with cookies.

Actual:

1. HTTP request omits cookies.

Note:

1. This does not happen on Chrome even if you turn the option to block third-party cookies and site data on.
2. Add-on SDK page-worker used to be able to load page with cookies. This bug affects my ability to port an Add-on SDK add-on to Web Extensions for Firefox.
3. Please let me know if there are alternatives to workaround this bug.