485539 - Tabs engine fails with 'tabChild is undefined'

Status: RESOLVED FIXED

(Cloud Services :: General, defect, P1)

Description

[Dan Mills [:thunder]]

I'm seeing this in my log with 0.2.118 (latest trunk atm):

Engine.Tabs          ERROR	Could not process incoming record: tabChild is undefined (module:tabs.js:229 :: TypeError)

Comment 1

[Jono Xia]

The line before that is:

for each (let tabChild in tabContainer.childNodes)

so I don't see how tabChild could be undefined, unless childNodes actually contains entries that are "undefined" instead of nodes.  I haven't been able to replicate this; I have a hunch that it's a side effect of some unusual state in the tab container.  Did you have any weird tabs open when it happened?  Any other extensions that do things to the tabs list?  Any clue about how to replicate would be good.

For now, I added code in http://hg.mozilla.org/labs/weave/rev/3b88ce58b6ba  that will handle this case and log a warning about it.  So people with this problem will be able to finish syncing, and we'll see warnings about it if it recurs.