1 files changed, 9 insertions, 0 deletions
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;