1810326 - Sync changes configurations on existing devices upon initial sync of new device

Status: NEW

(Firefox :: Sync, defect, P2)

Description

[account]

Attachment: Log of the initial sync on new device

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:108.0) Gecko/20100101 Firefox/108.0

Steps to reproduce:

• I have an established sync account with a lot of privacy related changes, such as disabling firefox's password manager (or at least the offer to save passwords to it) and I have noscript installed.
• When I start using a new computer I set up firefox sync on it, to sync in those settings, and preferably the noscript whitelist I have built up over time.

(fyi. I have a rather old sync account by now, so there may be some kind of old state embedded in it that I don't know of.)

Actual results:

• The addons are installed and most settings are synced to the new computer, but some settings don't seem to be applied to the new computer (specifically I noted noscript whitelist and whether or not to query to save passwords weren't saved).
• Worse yet the settings that weren't applied seem to have been back-synced to all my other devices, wiping my noscript whitelist and the password setting. I don't know if anything else is affected.

(This has been consistent over my last 4 additions of desktop firefox instances to my sync account.)

Expected results:

The settings in my sync account should be applied to the new device. If they fail to apply to the new device that failure shouldn't destroy the data in my sync account.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Firefox::Sync' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[account]

Attachment: Log of second sync from new device

Presumably is the log from when the wrong settings started to be propagated to my other devices.

Comment 3

[Mark Hammond [:markh] [:mhammond]]

what should happen in this scenario is that all the incoming preferences are applied locally - sadly though, the logs aren't don't capture enough info to know exactly what did happen and what prefs were applied. We should fix that, and also test this scenario better.

Comment 4

[Negritas Sergiu, Desktop QA]

Hello! As per the last comment I will mark it as NEW to give more visibility to this issue.

Have a nice day!