While most of the additional functionality the old account system had over the label system were irrelevant, there is one critical functionality that no longer seems to be possible with labels - specifically, the ability to request a list of transactions (TXID + amount) that pay to addresses with a given account/label. As per the release notes for 0.17.0. the listtransaction method was changed as follows;
The account named parameter has been renamed to dummy. If provided, the dummy parameter must be set to the string *, unless running with the -deprecatedrpc=accounts argument (in which case functionality is unchanged).
getreceivedbylabel and getreceivedbyaddress only returns the balance, while listreceivedbylabel and listreceivedbyaddress do not actually filter; additionally, the former does not list transactions at all, while the latter does not include the amounts per TXID. While you could use getaddressesbylabel to iterate over addresses, there is no corresponding method to get the TXIDs and amounts from this list of addresses. None of these can therefore be used as a direct replacement for this method.
The only way I can see to get anything resembling the old functionality with the API changes is to dump the entire transaction history with listreceivedbyaddress, filter the result by label manually, then use gettransaction on each listed TXID. This is both very fiddly and very inefficient, and likely impossible when you go past a certain number of lifetime transactions.
Am I missing something here, or will it really no longer possible be to iterate over transactions received by account/label? If so, this basically means that many applications will no longer be usable with releases starting from Bitcoin Core 0.18.
