We had this problem in our iOS app, solved it by using an array of ints wich are the increment-operations (well, we had uuids on them as well so we could determ

We had this problem in our iOS app, solved it by using an array of ints wich are the increment-operations (well, we had uuids on them as well so we could determine what was new and do a proper merge). But we merge by using differential synchronization (kinda) to resolve local changes and remote changes (to construct a "patch") by keeping an unchanged copy of the upstreams latest version (from the clients perspective).