[Bug]: Firefox sync compatibility

[victorxstc]

Pre-Submission Checklist

• I have checked the existing/closed issues to ensure this issue has not already been reported.
• I am using the latest supported version of the browser.
• I have tried disabling all browser extensions/add-ons to rule out interference from these.
• I have tried clearing the browser cache and cookies.
• I have checked with a new profile and the issue still occurs.
• I have provided detailed step-by-step instructions on how to reproduce the issue.
• I have included relevant screenshots or console outputs.
• I have checked that this problem is not occurring in the latest version of Firefox.
• This issue is specific to this browser and does not occur in other browsers.

Bug Summary

Disclaimer: I am NOT sure if this is a bug of Floorp. I am just writing it, in the hope that it might be useful to double-check the compatibility of syncing Floorp with Firefox. All I know is that this "bug" had never ever happened in Firefox, in the past 20, 25 years. This "bug" happened only and only once, and it was just after installing and syncing Floorp. So Floorp might play a role.

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TDLR: After logging in Floorp with my Firefox account, some (and not all) of my Firefox tabs have been randomly closed and disappeared, without my knowledge or control.

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Details:
I installed Floorp and synced into my main Firefox account (within Floorp). Floorp synced successfully without any problem. Next time I opened my original Firefox, I noted that some tabs have gone (closed). These tabs might be those that are repeated (for example, a Yahoo.com address was open in about 5, 6 different tabs and all of them but one disappeared). But this is not always the case; sometimes, repeated tabs do remain. It is a total mess, and I have no idea what the culprit is. I only know it has happened just after syncing Floorp with my Firefox.
The disappeared tabs seem to follow a pattern sometimes (those repeated ones), and not follow any visible pattern in other times (for example, some repeated tabs do remain, but some unique tabs have been closed).

Also one tab group is gone (closed) completely; that tab group had 4 tabs and was created 3 days ago; none of its tabs was repeated. Interestingly, this tab group does not even appear on Firefox's list of "All tab groups" that includes even the closed tab groups. This makes me think as if Firefox has reverted back to an earlier sync time.

Still, there are tabs still open that have been opened just yesterday etc, and have not been closed. I have also many tabs from a year ago that are not closed. So this bug might not necessarily been a reverting to a previous snapshot.

I have about 300, 400 tabs open in my original Firefox, most of which are in groups; Perhaps about 300 tabs are in groups, and about 100 tabs are open individually. So I don't remember exactly which tabs have been closed and which tabs remain open.

Reproduction Steps

No reproduction steps available

Expected Behavior

1. All the tabs open in the original Firefox must have remained exactly the same as before, after Floorp syncing.
2. Even if any tab is closed mysteriously in Firefox (after Floorp syncing), it should be shown at least in the list of closed tabs or the list of closed tab groups.

Actual Behavior

Some tabs or tab groups were randomly closed in the original Firefox, without appearing in the list of closed tabs.

Screenshots

NA

Browser Version

12.10.4@148.0 (64-bit)

Operating System

Windows 10

Additional Context

No response

[victorxstc]

I just noted that after syncing into my Firefox account (from Floorp), some of my extensions have been totally removed!! For example, my Firefox extension for Free Download Manager is now completely gone. It is neither in Firefox, nor in Floorp.

I am becoming more and more confident that the Floorp sync is dangerously problematic.

[victorxstc]

I re-installed the FDM extension. But guess what? It was deleted without my knowledge immediately.

Floorp is seriously F...ing around with my Firefox sync. Floorp is awesome, but its SYNC is TERRIBLE and even DANGEROUS.

(or perhaps something is going on in my PC, like a virus, etc. BUT whatever it is, it has started to happen after I installed and synced Floorp with my Firefox. And I dowonloaded Floorp from its official website, so it can't be infected.)

[Ryosuke-Asano]

Thanks for the report.

However, with the current information (no reproduction steps), we can’t triage this as a Floorp bug yet.

As a note: Firefox Sync “Tabs / Synced Tabs” is designed to publish the current open tabs of a device/profile and let other devices view them. It typically does not delete or overwrite another profile’s local tabs/session. What you’re describing is more consistent with session restore (sessionstore) rollback/corruption or a profile conflict (e.g., the same profile being used by multiple apps).

Could you please provide the following details so we can investigate?

1. OS, Floorp version, Firefox version
2. Whether Floorp and Firefox are using separate profiles:
   • Open about:profiles in BOTH apps and paste the “Root Directory” path for each
3. Whether Firefox was running at the same time when you signed into Sync in Floorp
4. Whether the tabs were lost in Floorp, or in your original Firefox installation/profile (please clarify which one)
5. Any errors in about:sync-log (attach relevant logs if possible)

Recovery tip (in case it helps): before doing anything else, back up your Firefox profile folder. Sometimes tabs can be recovered from <profile>/sessionstore-backups/ (e.g., previous.jsonlz4, recovery.jsonlz4, etc.).

Until we have the above info, we’ll mark this as needs-info.