1396849 - Deleted mobile bookmarks are downloaded back to device

Status: RESOLVED DUPLICATE of bug 1335201

(Firefox for iOS :: Sync, defect, P2)

Description

[Catalin Suciu [:csuciu]]

latest master

1. Add a new bookmark on device and sync it to desktop.
2. Delete the added bookmark from device.
4. Start a sync on device.

Expected: The record is deleted from server

Actual: The deleted record is downloaded back on device

Comment 1

[Richard Newman [:rnewman]]

Catalin, are you 100% sure that at step 1 both of the devices are completely in sync, with all bookmarks downloaded?

What happens if you add a sync on both devices after step 1?

My suspicion here is that what happens is:

1. iOS creates a bookmark and uploads it with no creation date. (Bug 1335201)
2. Desktop downloads it.
3. Desktop (or Android) reuploads it with a creation date.
4. iOS deletes the bookmark locally.
5. iOS syncs, downloads the record uploaded in #3, sees a conflict, and drops its local deletion.

If you sync after #3 and before #4 in my list, you should not see the reported behavior.

Comment 2

[Catalin Suciu [:csuciu]]

(In reply to Richard Newman [:rnewman] from comment #1)
> Catalin, are you 100% sure that at step 1 both of the devices are completely
> in sync, with all bookmarks downloaded?
Yes, I'm sure.
> 
> What happens if you add a sync on both devices after step 1?
> 
> My suspicion here is that what happens is:
> 
> 1. iOS creates a bookmark and uploads it with no creation date. (Bug 1335201)
> 2. Desktop downloads it.
> 3. Desktop (or Android) reuploads it with a creation date.
> 4. iOS deletes the bookmark locally.
> 5. iOS syncs, downloads the record uploaded in #3, sees a conflict, and
> drops its local deletion.
> 
> If you sync after #3 and before #4 in my list, you should not see the
> reported behavior.

I'll retest once bug #1397277 is fixed.

Comment 3

[Richard Newman [:rnewman]]

There's nothing to uplift.

Comment 4

[Richard Newman [:rnewman]]

(In reply to Richard Newman [:rnewman] from comment #1)

> My suspicion here is that what happens is…

And if I'm right, the very simplest thing to do is to fix Bug 1335201.

(Sync in general is crap at handling additive changes, detecting conflicts, and so on. This problem won't exist with 3WM.)

Comment 5

[Catalin Suciu [:csuciu]]

This issue is reproducible in stage also (train 95).

Comment 6

[Catalin Suciu [:csuciu]]

(In reply to Richard Newman [:rnewman] from comment #1)
> Catalin, are you 100% sure that at step 1 both of the devices are completely
> in sync, with all bookmarks downloaded?
> 
> What happens if you add a sync on both devices after step 1?

The bug is no longer reproducible.

Comment 7

[Richard Newman [:rnewman]]

(In reply to Catalin Suciu [:csuciu] from comment #6)

> The bug is no longer reproducible.

OK, great. Thanks for re-testing.

In that case I'm going to dupe this to the creation date bug, with the understanding that this is a limitation of Firefox Sync -- adding the creation date reduces the risk of a conflict (this bug is really "dataloss on conflict because Sync is simplistic"), and bidirectional sync will avoid this specific case by being more careful about merges.

Comment 8

[Stefan Arentz | :st3fan | ⏰ EST | he/him]

I also verified on production and things look good there too.