test: IsFinalTx returns true when there is no locktime

Author: brunoerg

src/test/miner_tests.cpp

@@ -523,6 +523,10 @@ void MinerTestingSetup::TestBasicMining(const CScript& scriptPubKey, const std::
     BOOST_CHECK(TestSequenceLocks(CTransaction{tx}, tx_mempool)); // Sequence locks pass
     BOOST_CHECK(IsFinalTx(CTransaction(tx), m_node.chainman->ActiveChain().Tip()->nHeight + 2, m_node.chainman->ActiveChain().Tip()->GetMedianTimePast())); // Locktime passes on 2nd block
 
+    // ensure tx is final for a specific case where there is no locktime and block height is zero
+    tx.nLockTime = 0;
+    BOOST_CHECK(IsFinalTx(CTransaction(tx), /*nBlockHeight=*/0, m_node.chainman->ActiveChain().Tip()->GetMedianTimePast()));
+
     // absolute time locked
     tx.vin[0].prevout.hash = txFirst[3]->GetHash();
     tx.nLockTime = m_node.chainman->ActiveChain().Tip()->GetMedianTimePast();