[Bug] Clawback owner count check should consider non-zero RippleStates only - or risks being fully unavailable about rippled

[WietseWind]

I like the Atomic approach 👍

[ximinez]

This kind of problem, unfortunately, has existed for a while with other features where the owner directory has to be empty. Fortunately, people haven't seemed to be too interested in doing it, I think partly because the reserve requirements can get expensive pretty quickly.

A problem with only checking the balance of a trust line is that it may not be sufficient. I think we'd also need to check the limit, because the limit is saying that the user already trusts the issuer for that amount, and changing parameters when trust has already been extended is not great. But if the limit is zero, then the only way to have a non-default trust line is with flags or quality, and what does that say about the user creating the trust line?

Another possible solution is the proposed Atomic transaction. One could fund the issuing account, then set all the flags in one atomic transaction. That would solve this entire class of problems.

Clearly the documentation needs to be updated, regardless of how this is addressed.