diff --git a/src/consensus/tx_verify.cpp b/src/consensus/tx_verify.cpp index f595f16eab..88d8da6ed5 100644 --- a/src/consensus/tx_verify.cpp +++ b/src/consensus/tx_verify.cpp @@ -20,6 +20,15 @@ bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime) return true; if ((int64_t)tx.nLockTime < ((int64_t)tx.nLockTime < LOCKTIME_THRESHOLD ? (int64_t)nBlockHeight : nBlockTime)) return true; + + // Even if tx.nLockTime isn't satisfied by nBlockHeight/nBlockTime, a + // transaction is still considered final if all inputs' nSequence == + // SEQUENCE_FINAL (0xffffffff), in which case nLockTime is ignored. + // + // Because of this behavior OP_CHECKLOCKTIMEVERIFY/CheckLockTime() will + // also check that the spending input's nSequence != SEQUENCE_FINAL, + // ensuring that an unsatisfied nLockTime value will actually cause + // IsFinalTx() to return false here: for (const auto& txin : tx.vin) { if (!(txin.nSequence == CTxIn::SEQUENCE_FINAL)) return false; diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp index 8cebbc5d10..ef48f89965 100644 --- a/src/script/interpreter.cpp +++ b/src/script/interpreter.cpp @@ -1740,9 +1740,9 @@ bool GenericTransactionSignatureChecker::CheckLockTime(const CScriptNum& nLoc if (nLockTime > (int64_t)txTo->nLockTime) return false; - // Finally the nLockTime feature can be disabled and thus - // CHECKLOCKTIMEVERIFY bypassed if every txin has been - // finalized by setting nSequence to maxint. The + // Finally the nLockTime feature can be disabled in IsFinalTx() + // and thus CHECKLOCKTIMEVERIFY bypassed if every txin has + // been finalized by setting nSequence to maxint. The // transaction would be allowed into the blockchain, making // the opcode ineffective. //