Custom operations might work incorrectly when they involve posts
It is something I've noticed in code when supplementing !494 (merged) (see comments there). When operations are processed, all the custom ops are stored aside and only at the end they are processed in their own loop. That creates an unwanted opportunity for those custom ops to target post that is later deleted and its permlink reused. When it happens in separate processing calls we'll get proper result (in live sync or when operations are separated by more than size of single pack of blocks which is 1000 at the moment) however when operations get processed in the same call (in initial sync when operations are not separated that much or in theoretical situation when all operations are in the same block) we'll get wrong result. In particular the probability of situation when we get proper result in live sync, but break it during resync, is high.
Actually the issue is not that important since the prerequisite of the problem is that permlink needs to be reused, so it depends on UI to reuse permlink after deleting post. However the problem is still there and at least some aspects of it seem to be easy to fix.