[whiskyrelaxing]

The two duplicate pubcoin checks in AcceptToMemoryPoolWorker return false
without setting CValidationState, so the caller learns that the transaction
failed and never why. Every other refusal in the same loop sets one, including
the matching pair for serials, zcspend-already-known and
zcspend-already-in-mempool.

A failed mint on 1.4.5.0 reports this:

ERROR: CommitTransaction(): Transaction cannot be broadcast immediately,  (code 0)
AutoZeromint: auto minting failed with error: Error: The transaction was
rejected! This might happen if some of the coins in your wallet were already
spent, such as if you used a copy of wallet.dat and coins were spent in the
copy but not marked as spent here.

Which is worse than confusing. CommitTransaction calls AddToWallet before it
tests the mempool, so for a mint funded from RingCT the anon wallet has already
marked the input spent. The balance drops, the transaction sits at zero
confirmations, and abandontransaction cannot release it because the flag lives
in AnonWallet mapRecords. Only rescanblockchain clears it.

#626 and #542 are the same wall with a different reason behind it, found both
times by reading debug.log.

state.Invalid forwards to DoS(0, ...), so nothing changes for peers.

[ohcee]

utACK