Right now it's really easy to stomp on yourself when using the rawtransactions api. For example, you write a transaction with some inputs of yours, you pass it off to another party to do $whatever, etc... and in the meantime you send some funds and those inputs get used out from under you.
Having a lock /unlock txid:vout| [comment] that prevents automatic coin selection from taking the inputs would solve that neatly.
This is indeed a serious issue if you plan to use both wallet-managed transactions and raw transactions.
Before something like you suggest here is implemented, I suppose the raw transaction interface needs a warning "do not combine with high-level wallet functions".
Isn't this sort-of what lockunspent does?
@laanwj Yes— sort of (see the date, this was written long before lockunspent)— though lockunspent isn't saved. Ultimately I think we need something that gets saved, though that brings up some extra challenges like needing to have a separated "locked balance" from "balance" so that uses don't get funds stuck in their wallet and have no way to figure out how (because they have balance they can't spend, or balance that isn't shown)
Closing as this is mostly solved (and a new issue opened for remainder).