miner_tests.cpp

// Copyright (c) 2011-2018 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <chainparams.h>
#include <coins.h>
#include <consensus/consensus.h>
#include <consensus/merkle.h>
#include <consensus/tx_verify.h>
#include <consensus/validation.h>
#include <validation.h>
#include <miner.h>
#include <policy/policy.h>
#include <pubkey.h>
#include <script/standard.h>
#include <txmempool.h>
#include <uint256.h>
#include <util/system.h>
#include <util/strencodings.h>

#include <test/test_bitcoin.h>

#include <memory>

#include <boost/test/unit_test.hpp>

BOOST_FIXTURE_TEST_SUITE(miner_tests, TestingSetup)

// BOOST_CHECK_EXCEPTION predicates to check the specific validation error
class HasReason {
public:
    explicit HasReason(const std::string& reason) : m_reason(reason) {}
    bool operator() (const std::runtime_error& e) const {
        return std::string(e.what()).find(m_reason) != std::string::npos;
    };
private:
    const std::string m_reason;
};

static CFeeRate blockMinFeeRate = CFeeRate(DEFAULT_BLOCK_MIN_TX_FEE);

static BlockAssembler AssemblerForTest(const CChainParams& params) {
    BlockAssembler::Options options;

    options.nBlockMaxWeight = MAX_BLOCK_WEIGHT;
    options.blockMinFeeRate = blockMinFeeRate;
    return BlockAssembler(params, options);
}

static
struct {
    unsigned char extranonce;
    unsigned int nonce;
} blockinfo[] = {
    {4, 0x00025dd2}, {2, 0x0002bac2}, {1, 0x00010d28}, {1, 0x0004f919},
    {2, 0x00018d4e}, {2, 0x00184637}, {1, 0x0003a704}, {2, 0x0020722e},
    {2, 0x0019c1c4}, {1, 0x000fb103}, {1, 0x0001f5c6}, {2, 0x00099e9c},
    {2, 0x00029fb7}, {1, 0x00045e88}, {2, 0x0016894b}, {2, 0x000d6e28},
    {1, 0x0020b304}, {2, 0x00059683}, {1, 0x000dcb06}, {1, 0x0001bd4e},
    {3, 0x000c8ad5}, {2, 0x0007568f}, {2, 0x00150cda}, {1, 0x0012f592},
    {2, 0x001709fc}, {1, 0x002367c9}, {2, 0x000ef108}, {2, 0x000b267a},
    {2, 0x0003d0ee}, {2, 0x0001845b}, {2, 0x00047b2e}, {2, 0x0002b47d},
    {1, 0x0011bf97}, {2, 0x000a3d43}, {2, 0x00007c8d}, {1, 0x00031b0c},
    {2, 0x0015f028}, {1, 0x00066021}, {2, 0x0005da49}, {1, 0x0007ecdd},
    {1, 0x0010a7c3}, {3, 0x000cdbe8}, {2, 0x000434bd}, {5, 0x000b428f},
    {1, 0x00132ec2}, {5, 0x0008a35e}, {1, 0x0002ff5a}, {1, 0x00101f31},
    {1, 0x000277fe}, {2, 0x000c52b0}, {1, 0x00069dab}, {1, 0x000d3d5c},
    {1, 0x001562e0}, {1, 0x000a06b1}, {5, 0x00091e0d}, {5, 0x00009bf5},
    {1, 0x001417ce}, {1, 0x0005e3c3}, {6, 0x0001aaf8}, {2, 0x000025df},
    {2, 0x00074f8c}, {1, 0x0006d5b1}, {1, 0x0007f3b5}, {1, 0x001a3ec0},
    {2, 0x0038262d}, {2, 0x000792d5}, {1, 0x0004d6ac}, {1, 0x001b3d60},
    {1, 0x000c3530}, {5, 0x00026529}, {5, 0x002d9530}, {1, 0x0001b83e},
    {1, 0x00045b71}, {2, 0x001795d6}, {2, 0x0016225e}, {1, 0x000ae574},
    {2, 0x000f2e03}, {1, 0x00034b0c}, {2, 0x00060dcc}, {2, 0x00035a82},
    {1, 0x00052546}, {1, 0x0008da58}, {1, 0x00213186}, {5, 0x000a0aa2},
    {1, 0x000ef8f4}, {1, 0x0004322e}, {1, 0x001bc035}, {1, 0x000857c1},
    {1, 0x001b7406}, {1, 0x00067578}, {1, 0x00010e1e}, {2, 0x002117db},
    {0, 0x00174e86}, {1, 0x0006600b}, {2, 0x0006d1e3}, {2, 0x00097877},
    {2, 0x000cb65e}, {1, 0x00034d68}, {1, 0x0008ad99}, {1, 0x0010427e},
    {1, 0x00126240}, {1, 0x0002b85c}, {1, 0x000b0e27}, {5, 0x000895c1},
    {2, 0x001f46b4}, {1, 0x00008594}, {1, 0x000c26d6}, {1, 0x000082ff},
    {2, 0x0010a4df}, {2, 0x000fb0e0},
};

static CBlockIndex CreateBlockIndex(int nHeight)
{
    CBlockIndex index;
    index.nHeight = nHeight;
    index.pprev = chainActive.Tip();
    return index;
}

static bool TestSequenceLocks(const CTransaction &tx, int flags) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
    LOCK(::mempool.cs);
    return CheckSequenceLocks(::mempool, tx, flags);
}

// Test suite for ancestor feerate transaction selection.
// Implemented as an additional function, rather than a separate test case,
// to allow reusing the blockchain created in CreateNewBlock_validity.
static void TestPackageSelection(const CChainParams& chainparams, const CScript& scriptPubKey, const std::vector<CTransactionRef>& txFirst) EXCLUSIVE_LOCKS_REQUIRED(cs_main, ::mempool.cs)
{
    // Test the ancestor feerate transaction selection.
    TestMemPoolEntryHelper entry;

    // Test that a medium fee transaction will be selected after a higher fee
    // rate package with a low fee rate parent.
    CMutableTransaction tx;
    tx.vin.resize(1);
    tx.vin[0].scriptSig = CScript() << OP_1;
    tx.vin[0].prevout.hash = txFirst[0]->GetHash();
    tx.vin[0].prevout.n = 0;
    tx.vout.resize(1);
    tx.vout[0].nValue = 5000000000LL - 1000;
    // This tx has a low fee: 1000 satoshis
    uint256 hashParentTx = tx.GetHash(); // save this txid for later use
    mempool.addUnchecked(entry.Fee(1000).Time(GetTime()).SpendsCoinbase(true).FromTx(tx));

    // This tx has a medium fee: 10000 satoshis
    tx.vin[0].prevout.hash = txFirst[1]->GetHash();
    tx.vout[0].nValue = 5000000000LL - 10000;
    uint256 hashMediumFeeTx = tx.GetHash();
    mempool.addUnchecked(entry.Fee(10000).Time(GetTime()).SpendsCoinbase(true).FromTx(tx));

    // This tx has a high fee, but depends on the first transaction
    tx.vin[0].prevout.hash = hashParentTx;
    tx.vout[0].nValue = 5000000000LL - 1000 - 50000; // 50k satoshi fee
    uint256 hashHighFeeTx = tx.GetHash();
    mempool.addUnchecked(entry.Fee(50000).Time(GetTime()).SpendsCoinbase(false).FromTx(tx));

    std::unique_ptr<CBlockTemplate> pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey);
    BOOST_CHECK(pblocktemplate->block.vtx[1]->GetHash() == hashParentTx);
    BOOST_CHECK(pblocktemplate->block.vtx[2]->GetHash() == hashHighFeeTx);
    BOOST_CHECK(pblocktemplate->block.vtx[3]->GetHash() == hashMediumFeeTx);

    // Test that a package below the block min tx fee doesn't get included
    tx.vin[0].prevout.hash = hashHighFeeTx;
    tx.vout[0].nValue = 5000000000LL - 1000 - 50000; // 0 fee
    uint256 hashFreeTx = tx.GetHash();
    mempool.addUnchecked(entry.Fee(0).FromTx(tx));
    size_t freeTxSize = ::GetSerializeSize(tx, PROTOCOL_VERSION);

    // Calculate a fee on child transaction that will put the package just
    // below the block min tx fee (assuming 1 child tx of the same size).
    CAmount feeToUse = blockMinFeeRate.GetFee(2*freeTxSize) - 1;

    tx.vin[0].prevout.hash = hashFreeTx;
    tx.vout[0].nValue = 5000000000LL - 1000 - 50000 - feeToUse;
    uint256 hashLowFeeTx = tx.GetHash();
    mempool.addUnchecked(entry.Fee(feeToUse).FromTx(tx));
    pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey);
    // Verify that the free tx and the low fee tx didn't get selected
    for (size_t i=0; i<pblocktemplate->block.vtx.size(); ++i) {
        BOOST_CHECK(pblocktemplate->block.vtx[i]->GetHash() != hashFreeTx);
        BOOST_CHECK(pblocktemplate->block.vtx[i]->GetHash() != hashLowFeeTx);
    }

    // Test that packages above the min relay fee do get included, even if one
    // of the transactions is below the min relay fee
    // Remove the low fee transaction and replace with a higher fee transaction
    mempool.removeRecursive(CTransaction(tx));
    tx.vout[0].nValue -= 2; // Now we should be just over the min relay fee
    hashLowFeeTx = tx.GetHash();
    mempool.addUnchecked(entry.Fee(feeToUse+2).FromTx(tx));
    pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey);
    BOOST_CHECK(pblocktemplate->block.vtx[4]->GetHash() == hashFreeTx);
    BOOST_CHECK(pblocktemplate->block.vtx[5]->GetHash() == hashLowFeeTx);

    // Test that transaction selection properly updates ancestor fee
    // calculations as ancestor transactions get included in a block.
    // Add a 0-fee transaction that has 2 outputs.
    tx.vin[0].prevout.hash = txFirst[2]->GetHash();
    tx.vout.resize(2);
    tx.vout[0].nValue = 5000000000LL - 100000000;
    tx.vout[1].nValue = 100000000; // 1BTC output
    uint256 hashFreeTx2 = tx.GetHash();
    mempool.addUnchecked(entry.Fee(0).SpendsCoinbase(true).FromTx(tx));

    // This tx can't be mined by itself
    tx.vin[0].prevout.hash = hashFreeTx2;
    tx.vout.resize(1);
    feeToUse = blockMinFeeRate.GetFee(freeTxSize);
    tx.vout[0].nValue = 5000000000LL - 100000000 - feeToUse;
    uint256 hashLowFeeTx2 = tx.GetHash();
    mempool.addUnchecked(entry.Fee(feeToUse).SpendsCoinbase(false).FromTx(tx));
    pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey);

    // Verify that this tx isn't selected.
    for (size_t i=0; i<pblocktemplate->block.vtx.size(); ++i) {
        BOOST_CHECK(pblocktemplate->block.vtx[i]->GetHash() != hashFreeTx2);
        BOOST_CHECK(pblocktemplate->block.vtx[i]->GetHash() != hashLowFeeTx2);
    }

    // This tx will be mineable, and should cause hashLowFeeTx2 to be selected
    // as well.
    tx.vin[0].prevout.n = 1;
    tx.vout[0].nValue = 100000000 - 10000; // 10k satoshi fee
    mempool.addUnchecked(entry.Fee(10000).FromTx(tx));
    pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey);
    BOOST_CHECK(pblocktemplate->block.vtx[8]->GetHash() == hashLowFeeTx2);
}

// NOTE: These tests rely on CreateNewBlock doing its own self-validation!
BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
{
    // Note that by default, these tests run with size accounting enabled.
    const auto chainParams = CreateChainParams(CBaseChainParams::MAIN);
    const CChainParams& chainparams = *chainParams;
    CScript scriptPubKey = CScript() << ParseHex("04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f") << OP_CHECKSIG;
    std::unique_ptr<CBlockTemplate> pblocktemplate;
    CMutableTransaction tx;
    CScript script;
    uint256 hash;
    TestMemPoolEntryHelper entry;
    entry.nFee = 11;
    entry.nHeight = 11;

    fCheckpointsEnabled = false;

    // Simple block creation, nothing special yet:
    BOOST_CHECK(pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey));

    // We can't make transactions until we have inputs
    // Therefore, load 100 blocks :)
    int baseheight = 0;
    std::vector<CTransactionRef> txFirst;
    for (unsigned int i = 0; i < sizeof(blockinfo)/sizeof(*blockinfo); ++i)
    {
        CBlock *pblock = &pblocktemplate->block; // pointer for convenience
        {
            LOCK(cs_main);
            pblock->nVersion = 1;
            pblock->nTime = chainActive.Tip()->GetMedianTimePast()+1;
            CMutableTransaction txCoinbase(*pblock->vtx[0]);
            txCoinbase.nVersion = 1;
            txCoinbase.vin[0].scriptSig = CScript();
            txCoinbase.vin[0].scriptSig.push_back(blockinfo[i].extranonce);
            txCoinbase.vin[0].scriptSig.push_back(chainActive.Height());
            txCoinbase.vout.resize(1); // Ignore the (optional) segwit commitment added by CreateNewBlock (as the hardcoded nonces don't account for this)
            txCoinbase.vout[0].scriptPubKey = CScript();
            pblock->vtx[0] = MakeTransactionRef(std::move(txCoinbase));
            if (txFirst.size() == 0)
                baseheight = chainActive.Height();
            if (txFirst.size() < 4)
                txFirst.push_back(pblock->vtx[0]);
            pblock->hashMerkleRoot = BlockMerkleRoot(*pblock);
            pblock->nNonce = blockinfo[i].nonce;
        }
        std::shared_ptr<const CBlock> shared_pblock = std::make_shared<const CBlock>(*pblock);
        BOOST_CHECK(ProcessNewBlock(chainparams, shared_pblock, true, nullptr));
        pblock->hashPrevBlock = pblock->GetHash();
    }

    LOCK(cs_main);
    LOCK(::mempool.cs);

    // Just to make sure we can still make simple blocks
    BOOST_CHECK(pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey));

    const CAmount BLOCKSUBSIDY = 50*COIN;
    const CAmount LOWFEE = CENT;
    const CAmount HIGHFEE = COIN;
    const CAmount HIGHERFEE = 4*COIN;

    // block sigops > limit: 1000 CHECKMULTISIG + 1
    tx.vin.resize(1);
    // NOTE: OP_NOP is used to force 20 SigOps for the CHECKMULTISIG
    tx.vin[0].scriptSig = CScript() << OP_0 << OP_0 << OP_0 << OP_NOP << OP_CHECKMULTISIG << OP_1;
    tx.vin[0].prevout.hash = txFirst[0]->GetHash();
    tx.vin[0].prevout.n = 0;
    tx.vout.resize(1);
    tx.vout[0].nValue = BLOCKSUBSIDY;
    for (unsigned int i = 0; i < 1001; ++i)
    {
        tx.vout[0].nValue -= LOWFEE;
        hash = tx.GetHash();
        bool spendsCoinbase = i == 0; // only first tx spends coinbase
        // If we don't set the # of sig ops in the CTxMemPoolEntry, template creation fails
        mempool.addUnchecked(entry.Fee(LOWFEE).Time(GetTime()).SpendsCoinbase(spendsCoinbase).FromTx(tx));
        tx.vin[0].prevout.hash = hash;
    }

    BOOST_CHECK_EXCEPTION(AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey), std::runtime_error, HasReason("bad-blk-sigops"));
    mempool.clear();

    tx.vin[0].prevout.hash = txFirst[0]->GetHash();
    tx.vout[0].nValue = BLOCKSUBSIDY;
    for (unsigned int i = 0; i < 1001; ++i)
    {
        tx.vout[0].nValue -= LOWFEE;
        hash = tx.GetHash();
        bool spendsCoinbase = i == 0; // only first tx spends coinbase
        // If we do set the # of sig ops in the CTxMemPoolEntry, template creation passes
        mempool.addUnchecked(entry.Fee(LOWFEE).Time(GetTime()).SpendsCoinbase(spendsCoinbase).SigOpsCost(80).FromTx(tx));
        tx.vin[0].prevout.hash = hash;
    }
    BOOST_CHECK(pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey));
    mempool.clear();

    // block size > limit
    tx.vin[0].scriptSig = CScript();
    // 18 * (520char + DROP) + OP_1 = 9433 bytes
    std::vector<unsigned char> vchData(520);
    for (unsigned int i = 0; i < 18; ++i)
        tx.vin[0].scriptSig << vchData << OP_DROP;
    tx.vin[0].scriptSig << OP_1;
    tx.vin[0].prevout.hash = txFirst[0]->GetHash();
    tx.vout[0].nValue = BLOCKSUBSIDY;
    for (unsigned int i = 0; i < 128; ++i)
    {
        tx.vout[0].nValue -= LOWFEE;
        hash = tx.GetHash();
        bool spendsCoinbase = i == 0; // only first tx spends coinbase
        mempool.addUnchecked(entry.Fee(LOWFEE).Time(GetTime()).SpendsCoinbase(spendsCoinbase).FromTx(tx));
        tx.vin[0].prevout.hash = hash;
    }
    BOOST_CHECK(pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey));
    mempool.clear();

    // orphan in mempool, template creation fails
    hash = tx.GetHash();
    mempool.addUnchecked(entry.Fee(LOWFEE).Time(GetTime()).FromTx(tx));
    BOOST_CHECK_EXCEPTION(AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey), std::runtime_error, HasReason("bad-txns-inputs-missingorspent"));
    mempool.clear();

    // child with higher feerate than parent
    tx.vin[0].scriptSig = CScript() << OP_1;
    tx.vin[0].prevout.hash = txFirst[1]->GetHash();
    tx.vout[0].nValue = BLOCKSUBSIDY-HIGHFEE;
    hash = tx.GetHash();
    mempool.addUnchecked(entry.Fee(HIGHFEE).Time(GetTime()).SpendsCoinbase(true).FromTx(tx));
    tx.vin[0].prevout.hash = hash;
    tx.vin.resize(2);
    tx.vin[1].scriptSig = CScript() << OP_1;
    tx.vin[1].prevout.hash = txFirst[0]->GetHash();
    tx.vin[1].prevout.n = 0;
    tx.vout[0].nValue = tx.vout[0].nValue+BLOCKSUBSIDY-HIGHERFEE; //First txn output + fresh coinbase - new txn fee
    hash = tx.GetHash();
    mempool.addUnchecked(entry.Fee(HIGHERFEE).Time(GetTime()).SpendsCoinbase(true).FromTx(tx));
    BOOST_CHECK(pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey));
    mempool.clear();

    // coinbase in mempool, template creation fails
    tx.vin.resize(1);
    tx.vin[0].prevout.SetNull();
    tx.vin[0].scriptSig = CScript() << OP_0 << OP_1;
    tx.vout[0].nValue = 0;
    hash = tx.GetHash();
    // give it a fee so it'll get mined
    mempool.addUnchecked(entry.Fee(LOWFEE).Time(GetTime()).SpendsCoinbase(false).FromTx(tx));
    // Should throw bad-cb-multiple
    BOOST_CHECK_EXCEPTION(AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey), std::runtime_error, HasReason("bad-cb-multiple"));
    mempool.clear();

    // double spend txn pair in mempool, template creation fails
    tx.vin[0].prevout.hash = txFirst[0]->GetHash();
    tx.vin[0].scriptSig = CScript() << OP_1;
    tx.vout[0].nValue = BLOCKSUBSIDY-HIGHFEE;
    tx.vout[0].scriptPubKey = CScript() << OP_1;
    hash = tx.GetHash();
    mempool.addUnchecked(entry.Fee(HIGHFEE).Time(GetTime()).SpendsCoinbase(true).FromTx(tx));
    tx.vout[0].scriptPubKey = CScript() << OP_2;
    hash = tx.GetHash();
    mempool.addUnchecked(entry.Fee(HIGHFEE).Time(GetTime()).SpendsCoinbase(true).FromTx(tx));
    BOOST_CHECK_EXCEPTION(AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey), std::runtime_error, HasReason("bad-txns-inputs-missingorspent"));
    mempool.clear();

    // subsidy changing
    int nHeight = chainActive.Height();
    // Create an actual 209999-long block chain (without valid blocks).
    while (chainActive.Tip()->nHeight < 839999) {
        CBlockIndex* prev = chainActive.Tip();
        CBlockIndex* next = new CBlockIndex();
        next->phashBlock = new uint256(InsecureRand256());
        pcoinsTip->SetBestBlock(next->GetBlockHash());
        next->pprev = prev;
        next->nHeight = prev->nHeight + 1;
        next->BuildSkip();
        chainActive.SetTip(next);
    }
    BOOST_CHECK(pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey));
    // Extend to a 210000-long block chain.
    while (chainActive.Tip()->nHeight < 840000) {
        CBlockIndex* prev = chainActive.Tip();
        CBlockIndex* next = new CBlockIndex();
        next->phashBlock = new uint256(InsecureRand256());
        pcoinsTip->SetBestBlock(next->GetBlockHash());
        next->pprev = prev;
        next->nHeight = prev->nHeight + 1;
        next->BuildSkip();
        chainActive.SetTip(next);
    }
    BOOST_CHECK(pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey));

    // invalid p2sh txn in mempool, template creation fails
    tx.vin[0].prevout.hash = txFirst[0]->GetHash();
    tx.vin[0].prevout.n = 0;
    tx.vin[0].scriptSig = CScript() << OP_1;
    tx.vout[0].nValue = BLOCKSUBSIDY-LOWFEE;
    script = CScript() << OP_0;
    tx.vout[0].scriptPubKey = GetScriptForDestination(CScriptID(script));
    hash = tx.GetHash();
    mempool.addUnchecked(entry.Fee(LOWFEE).Time(GetTime()).SpendsCoinbase(true).FromTx(tx));
    tx.vin[0].prevout.hash = hash;
    tx.vin[0].scriptSig = CScript() << std::vector<unsigned char>(script.begin(), script.end());
    tx.vout[0].nValue -= LOWFEE;
    hash = tx.GetHash();
    mempool.addUnchecked(entry.Fee(LOWFEE).Time(GetTime()).SpendsCoinbase(false).FromTx(tx));
    // Should throw block-validation-failed
    BOOST_CHECK_EXCEPTION(AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey), std::runtime_error, HasReason("block-validation-failed"));
    mempool.clear();

    // Delete the dummy blocks again.
    while (chainActive.Tip()->nHeight > nHeight) {
        CBlockIndex* del = chainActive.Tip();
        chainActive.SetTip(del->pprev);
        pcoinsTip->SetBestBlock(del->pprev->GetBlockHash());
        delete del->phashBlock;
        delete del;
    }

    // non-final txs in mempool
    SetMockTime(chainActive.Tip()->GetMedianTimePast()+1);
    int flags = LOCKTIME_VERIFY_SEQUENCE|LOCKTIME_MEDIAN_TIME_PAST;
    // height map
    std::vector<int> prevheights;

    // relative height locked
    tx.nVersion = 2;
    tx.vin.resize(1);
    prevheights.resize(1);
    tx.vin[0].prevout.hash = txFirst[0]->GetHash(); // only 1 transaction
    tx.vin[0].prevout.n = 0;
    tx.vin[0].scriptSig = CScript() << OP_1;
    tx.vin[0].nSequence = chainActive.Tip()->nHeight + 1; // txFirst[0] is the 2nd block
    prevheights[0] = baseheight + 1;
    tx.vout.resize(1);
    tx.vout[0].nValue = BLOCKSUBSIDY-HIGHFEE;
    tx.vout[0].scriptPubKey = CScript() << OP_1;
    tx.nLockTime = 0;
    hash = tx.GetHash();
    mempool.addUnchecked(entry.Fee(HIGHFEE).Time(GetTime()).SpendsCoinbase(true).FromTx(tx));
    BOOST_CHECK(CheckFinalTx(CTransaction(tx), flags)); // Locktime passes
    BOOST_CHECK(!TestSequenceLocks(CTransaction(tx), flags)); // Sequence locks fail
    BOOST_CHECK(SequenceLocks(CTransaction(tx), flags, &prevheights, CreateBlockIndex(chainActive.Tip()->nHeight + 2))); // Sequence locks pass on 2nd block

    // relative time locked
    tx.vin[0].prevout.hash = txFirst[1]->GetHash();
    tx.vin[0].nSequence = CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG | (((chainActive.Tip()->GetMedianTimePast()+1-chainActive[1]->GetMedianTimePast()) >> CTxIn::SEQUENCE_LOCKTIME_GRANULARITY) + 1); // txFirst[1] is the 3rd block
    prevheights[0] = baseheight + 2;
    hash = tx.GetHash();
    mempool.addUnchecked(entry.Time(GetTime()).FromTx(tx));
    BOOST_CHECK(CheckFinalTx(CTransaction(tx), flags)); // Locktime passes
    BOOST_CHECK(!TestSequenceLocks(CTransaction(tx), flags)); // Sequence locks fail

    for (int i = 0; i < CBlockIndex::nMedianTimeSpan; i++)
        chainActive.Tip()->GetAncestor(chainActive.Tip()->nHeight - i)->nTime += 512; //Trick the MedianTimePast
    BOOST_CHECK(SequenceLocks(CTransaction(tx), flags, &prevheights, CreateBlockIndex(chainActive.Tip()->nHeight + 1))); // Sequence locks pass 512 seconds later
    for (int i = 0; i < CBlockIndex::nMedianTimeSpan; i++)
        chainActive.Tip()->GetAncestor(chainActive.Tip()->nHeight - i)->nTime -= 512; //undo tricked MTP

    // absolute height locked
    tx.vin[0].prevout.hash = txFirst[2]->GetHash();
    tx.vin[0].nSequence = CTxIn::SEQUENCE_FINAL - 1;
    prevheights[0] = baseheight + 3;
    tx.nLockTime = chainActive.Tip()->nHeight + 1;
    hash = tx.GetHash();
    mempool.addUnchecked(entry.Time(GetTime()).FromTx(tx));
    BOOST_CHECK(!CheckFinalTx(CTransaction(tx), flags)); // Locktime fails
    BOOST_CHECK(TestSequenceLocks(CTransaction(tx), flags)); // Sequence locks pass
    BOOST_CHECK(IsFinalTx(CTransaction(tx), chainActive.Tip()->nHeight + 2, chainActive.Tip()->GetMedianTimePast())); // Locktime passes on 2nd block

    // absolute time locked
    tx.vin[0].prevout.hash = txFirst[3]->GetHash();
    tx.nLockTime = chainActive.Tip()->GetMedianTimePast();
    prevheights.resize(1);
    prevheights[0] = baseheight + 4;
    hash = tx.GetHash();
    mempool.addUnchecked(entry.Time(GetTime()).FromTx(tx));
    BOOST_CHECK(!CheckFinalTx(CTransaction(tx), flags)); // Locktime fails
    BOOST_CHECK(TestSequenceLocks(CTransaction(tx), flags)); // Sequence locks pass
    BOOST_CHECK(IsFinalTx(CTransaction(tx), chainActive.Tip()->nHeight + 2, chainActive.Tip()->GetMedianTimePast() + 1)); // Locktime passes 1 second later

    // mempool-dependent transactions (not added)
    tx.vin[0].prevout.hash = hash;
    prevheights[0] = chainActive.Tip()->nHeight + 1;
    tx.nLockTime = 0;
    tx.vin[0].nSequence = 0;
    BOOST_CHECK(CheckFinalTx(CTransaction(tx), flags)); // Locktime passes
    BOOST_CHECK(TestSequenceLocks(CTransaction(tx), flags)); // Sequence locks pass
    tx.vin[0].nSequence = 1;
    BOOST_CHECK(!TestSequenceLocks(CTransaction(tx), flags)); // Sequence locks fail
    tx.vin[0].nSequence = CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG;
    BOOST_CHECK(TestSequenceLocks(CTransaction(tx), flags)); // Sequence locks pass
    tx.vin[0].nSequence = CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG | 1;
    BOOST_CHECK(!TestSequenceLocks(CTransaction(tx), flags)); // Sequence locks fail

    BOOST_CHECK(pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey));

    // None of the of the absolute height/time locked tx should have made
    // it into the template because we still check IsFinalTx in CreateNewBlock,
    // but relative locked txs will if inconsistently added to mempool.
    // For now these will still generate a valid template until BIP68 soft fork
    BOOST_CHECK_EQUAL(pblocktemplate->block.vtx.size(), 3U);
    // However if we advance height by 1 and time by 512, all of them should be mined
    for (int i = 0; i < CBlockIndex::nMedianTimeSpan; i++)
        chainActive.Tip()->GetAncestor(chainActive.Tip()->nHeight - i)->nTime += 512; //Trick the MedianTimePast
    chainActive.Tip()->nHeight++;
    SetMockTime(chainActive.Tip()->GetMedianTimePast() + 1);

    BOOST_CHECK(pblocktemplate = AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey));
    BOOST_CHECK_EQUAL(pblocktemplate->block.vtx.size(), 5U);

    chainActive.Tip()->nHeight--;
    SetMockTime(0);
    mempool.clear();

    TestPackageSelection(chainparams, scriptPubKey, txFirst);

    fCheckpointsEnabled = true;
}

BOOST_AUTO_TEST_SUITE_END()