HLAPI Syncgroup Double Join on invite

[afandria]

It appears (at least on TODOs) that we might be double joining a syncgroup. These back-to-back joins are triggering an error in the code, but we shouldn't be firing the invite callback twice in the first place.

Is it possible that we're advertising double?

@azinman

[afandria]

No, this isn't actually a double advertise. It's actually "normal".

We join once from syncgroup invite and once from userdata watch. This error started being logged because the lower layer had a bug introduced into it. We are looking into fixing it in v.io/c/23930

The error is that a collection (from the syncgroup) does not exist. This error tends to fire after a double join; the second join notices that the collection doesn't yet exist, but fails to realize that the sync is still pending (so it's okay for the collection not to exist yet).