1636001 - "Delete cookies & data when Firefox is closed" feature fails to honor permission exceptions when first-party isolation is enabled

Status: RESOLVED DUPLICATE of bug 1556212

(Toolkit :: Data Sanitization, defect)

Description

[Ronan Jouchet]

Attachment: firefox-bug-firstpartyisolation-breaks-permissions-exceptions.webm

Steps to reproduce

See detailed attached screencast:

1. In about:config, enable privacy.firstparty.isolate .
2. In about:preferences#privacy → Manage Permissions, add an Allow rule for news.ycombinator.com .
3. Nearby, enable the Delete cookies and site data when Nightly is closed option.
4. Open HN and log in. Validate that you are logged in, and that a news.ycombinator.com line (actually, two: one for http and one for https) appears in about:preferences → Manage Data
5. Exit and relaunch Firefox.

Actual results

privacy.firstparty.isolate caused Firefox to fail to honor the Allow exception when running the Delete cookies and site data when Nightly is closed feature on browser exit: after the restart,

• User is logged out.
• And indeed, looking at about:preferences#privacy → Manage Data, HN data/cookies are absent; they were deleted on exit.

Expected results

Firefox should have honored my Allow exception when running the Delete cookies and site data when Nightly is closed feature on browser exit:

• User should have remain logged in after the restart.
• Looking at about:preferences#privacy → Manage Data, HN data/cookies should have been preserved by the Allow rule during the exit/restart.

Context / additional information

• Firefox 78.0a1 / 20200506215114, linux x64.
• Fresh new profile, no configuration, no addons.
• As demonstrated in the second section of the screencast (starting at 2:20), problem is caused by privacy.firstparty.isolate, and disappears when flipping the pref back to false.
• My HN password, whose length is visible on the video, was changed.