1967285 - "Delete cookies and site data when Firefox is closed" not working on close

Status: NEW

(Toolkit :: Data Sanitization, enhancement, P3)

Description

[MattH]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:138.0) Gecko/20100101 Firefox/138.0

Steps to reproduce:

1. Log into Gmail
2. Verify cookie is set via under Firefox setting "Manage cookies and site data"
3. Verify that Firefox setting "Delete cookies and site data when Firefox is closed" is checked
4. Click the "X" to close Firefox
5. Re-launch Firefox
6. Go to gmail.google.com and notice it sign in without prompting (bug)
7. Confirm under Firefox setting "Manage cookies and site data" that the cookie was not deleted when the browser was closed

Actual results:

Cookie for Gmail was not deleted when Firefox was closed even though the setting "Delete cookies and site data when Firefox is closed" was selected.

Expected results:

Cookie for Gmail should have been deleted when Firefox was closed when the setting "Delete cookies and site data when Firefox is closed" was selected.

Additional notes: Macbook Pro 16" 2023, Sequoia 15.5, Firefox 138.0.4
Other detail: I notice that Firefox continues to run as a process in the background on the Mac even when it is closed. This is likely related to the source of the bug because if I kill the Firefox background process, the cookies are deleted. It seems that when the user closes Firefox, the background process is not stopping (possibly for performance optimization of later startup again) and then the cookie option is not considering the user close to be a close of Firefox because of the non-visible background process left running outside of user awareness or easy control. This is a clear user experience bug that has security and privacy implications.

Comment 1

[Harshit Sohaney [:hsohaney]]

Clicking the "X" on macos doesn't close the application (that's just the macos standard). Other browser's follow this behavior. Given this, this is expected behavior.
However, I recognize the UX problem here, and have seen other bugs related to this behavior, so I'll keep this open as an enhancement request to change the behavior with the "X".