1220379 - DataCloneError isn't handled in home screen data store mirrors

Status: RESOLVED FIXED

(Firefox OS Graveyard :: Gaia::Homescreen, defect)

Description

[Chris Lord [:cwiiis]]

[Blocking Requested - why for this release]: Core behaviour can be (practically) irreversibly  broken

So I'm not sure how this came about, but I'm using a phone that has years worth of history and there's an entry that produces a DataCloneError when mirroring in the home screen places datastore mirror.

It throws an exception which doesn't get handled and this stops any subsequent pinned pages interaction from working. The only way to recover is to manipulate the store-mirror object via WebIDE, which is obviously no good.

Comment 1

[GitHub Autolander Bot]

Attachment: [gaia] Cwiiis:bug1220379-homescreen-dataclone-error > mozilla-b2g:master

Comment 2

[Chris Lord [:cwiiis]]

What I find really odd about this is that datastore is backed internally by an indexeddb - it seems weird that any data from a datastore would fail due to a DataCloneError (which is why this code wasn't guarded in the first place), but it obviously can happen in practice. Note, I've never seen this on any test devices, only on my personal phone (which has a *lot* of legacy - I've carried the profile over several different versions and phones).

Comment 3

[Guillaume Marty [:gmarty]]

Comment on attachment 8681618 [details] [review]
[gaia] Cwiiis:bug1220379-homescreen-dataclone-error > mozilla-b2g:master

Looks good to me.
Can you land it and maybe write a couple of simple unit tests in a follow up? As I understand this bug is quite rare so we want to make sure we don't regress.

Comment 4

[Carsten Book [:Tomcat]]

https://github.com/mozilla-b2g/gaia/commit/cd194649986bfe849fc80804fcb72ecd5cf7989b