Affected versions

• 105.0a1(2022-08-08)

Found in

• 105.0a1(2022-08-08)

Affected platforms

• Windows 11x64
• Ubuntu 22.04
• macOS 12

Steps to reproduce

1. Launch FF .
2. Activate the browser.tabs.firefox-view pref.
3. Log into sync on device A.
4. Log into sync on device B.
5. Perform browsing activity on device B.
6. Open a new private window on device A.
7. Go to about:privateview in the private window.

Expected result

• The Tab Pick up section should be blank without any traffic registered(that was performed on device B) on the aboutfirefoxview page from the private window on device A.

Actual result

• Tab Pickup section registers traffic performed on device B in real-time in a private window.

Regression range

• New Feature

Are we sure this is a bug? The browsing on device B was not private, so its correct that any tabs from that device should be synced and listed on device A. The expectation is that browsing conducted in a private window/tab is not synced or preserved in any way. Normal browsing history, saved logins, downloads etc in a non-private window continue to be available in the private window. This is how it work today for the other synced tab views - If I check the synced tabs list from the FxA menu in a private window, it will reflect the (non-private) tabs I have open in my secondary device. I would expect firefox view's Tab Pickup synced tabs list to behave the same.

I agree that there is a risk that people treat private browsing as a kind of profile-lite, and expect a partition to exist between browsing they do in non-private windows and private windows. We've had the same bugs filed repeatedly with the password manager - where people are surprised that their saved logins show up as suggestions in private browsing tabs. The guarantee we give to users is that no activity will leak in the other direction - no tabs opened, no browsing history taking place in private browsing will get recorded or synced. Not the other way around.

Anyhow, I hope I've understood the report and STR correctly, otherwise I've just confused the issue.

Good point of clarification Sam. I think you're correct. If the browsing was done outside of a private window, then that information would still be fine to surface in a private window. But activity done inside of the private window session should not be preserved for either normal or private windows.

I'm going to close this as invalid. If I've misunderstood the issue or comments 2, 3 and 4 don't adequately explain why please re-open and/or let me know.