Merge bitcoin#28922: Use Txid in COutpoint

9e58c5b Use Txid in COutpoint (dergoegge)

Pull request description:

  This PR changes the type of the hash of a transaction outpoint from `uint256` to `Txid`.

ACKs for top commit:
  Sjors:
    ACK 9e58c5b
  stickies-v:
    ACK 9e58c5b. A sizeable diff, but very straightforward changes. Didn't see anything controversial. Left a few nits, but nothing blocking, only if you have to retouch.
  TheCharlatan:
    ACK 9e58c5b

Tree-SHA512: 58f61ce1c58668f689513e62072a7775419c4d5af8f607669cd8cdc2e7be9645ba14af7f9e2d65da2670da3ec1ce7fc2a744037520caf799aba212fd1ac44b34

src/bench/disconnected_transactions.cpp

@@ -28,7 +28,7 @@ struct ReorgTxns {
 static BlockTxns CreateRandomTransactions(size_t num_txns)
 {
     // Ensure every transaction has a different txid by having each one spend the previous one.
-    static uint256 prevout_hash{uint256::ZERO};
+    static Txid prevout_hash{};
 
     BlockTxns txns;
     txns.reserve(num_txns);

src/bench/duplicate_inputs.cpp

@@ -47,7 +47,7 @@ static void DuplicateInputs(benchmark::Bench& bench)
 
     uint64_t n_inputs = (((MAX_BLOCK_SERIALIZED_SIZE / WITNESS_SCALE_FACTOR) - (CTransaction(coinbaseTx).GetTotalSize() + CTransaction(naughtyTx).GetTotalSize())) / 41) - 100;
     for (uint64_t x = 0; x < (n_inputs - 1); ++x) {
-        naughtyTx.vin.emplace_back(GetRandHash(), 0, CScript(), 0);
+        naughtyTx.vin.emplace_back(Txid::FromUint256(GetRandHash()), 0, CScript(), 0);
     }
     naughtyTx.vin.emplace_back(naughtyTx.vin.back());
 

src/bench/mempool_stress.cpp

@@ -56,7 +56,7 @@ static std::vector<CTransactionRef> CreateOrderedCoins(FastRandomContext& det_ra
         for (size_t ancestor = 0; ancestor < n_ancestors && !available_coins.empty(); ++ancestor){
             size_t idx = det_rand.randrange(available_coins.size());
             Available coin = available_coins[idx];
-            uint256 hash = coin.ref->GetHash();
+            Txid hash = coin.ref->GetHash();
             // biased towards taking min_ancestors parents, but maybe more
             size_t n_to_take = det_rand.randrange(2) == 0 ?
                                min_ancestors :

src/bitcoin-tx.cpp

@@ -280,7 +280,7 @@ static void MutateTxAddInput(CMutableTransaction& tx, const std::string& strInpu
     }
 
     // append to transaction input list
-    CTxIn txin(txid, vout, CScript(), nSequenceIn);
+    CTxIn txin(Txid::FromUint256(txid), vout, CScript(), nSequenceIn);
     tx.vin.push_back(txin);
 }
 
@@ -629,7 +629,7 @@ static void MutateTxSign(CMutableTransaction& tx, const std::string& flagStr)
             if (nOut < 0)
                 throw std::runtime_error("vout cannot be negative");
 
-            COutPoint out(txid, nOut);
+            COutPoint out(Txid::FromUint256(txid), nOut);
             std::vector<unsigned char> pkData(ParseHexUV(prevOut["scriptPubKey"], "scriptPubKey"));
             CScript scriptPubKey(pkData.begin(), pkData.end());
 

src/coins.cpp

@@ -116,7 +116,7 @@ void CCoinsViewCache::EmplaceCoinInternalDANGER(COutPoint&& outpoint, Coin&& coi
 
 void AddCoins(CCoinsViewCache& cache, const CTransaction &tx, int nHeight, bool check_for_overwrite) {
     bool fCoinbase = tx.IsCoinBase();
-    const uint256& txid = tx.GetHash();
+    const Txid& txid = tx.GetHash();
     for (size_t i = 0; i < tx.vout.size(); ++i) {
         bool overwrite = check_for_overwrite ? cache.HaveCoin(COutPoint(txid, i)) : fCoinbase;
         // Coinbase transactions can always be overwritten, in order to correctly
@@ -341,7 +341,7 @@ void CCoinsViewCache::SanityCheck() const
 static const size_t MIN_TRANSACTION_OUTPUT_WEIGHT = WITNESS_SCALE_FACTOR * ::GetSerializeSize(CTxOut());
 static const size_t MAX_OUTPUTS_PER_BLOCK = MAX_BLOCK_WEIGHT / MIN_TRANSACTION_OUTPUT_WEIGHT;
 
-const Coin& AccessByTxid(const CCoinsViewCache& view, const uint256& txid)
+const Coin& AccessByTxid(const CCoinsViewCache& view, const Txid& txid)
 {
     COutPoint iter(txid, 0);
     while (iter.n < MAX_OUTPUTS_PER_BLOCK) {

src/coins.h

@@ -363,7 +363,7 @@ void AddCoins(CCoinsViewCache& cache, const CTransaction& tx, int nHeight, bool
 //! This function can be quite expensive because in the event of a transaction
 //! which is not found in the cache, it can cause up to MAX_OUTPUTS_PER_BLOCK
 //! lookups to database, so it should be used with care.
-const Coin& AccessByTxid(const CCoinsViewCache& cache, const uint256& txid);
+const Coin& AccessByTxid(const CCoinsViewCache& cache, const Txid& txid);
 
 /**
  * This is a minimally invasive approach to shutdown on LevelDB read errors from the

src/common/bloom.cpp

@@ -98,8 +98,8 @@ bool CBloomFilter::IsRelevantAndUpdate(const CTransaction& tx)
     //  for finding tx when they appear in a block
     if (vData.empty()) // zero-size = "match-all" filter
         return true;
-    const uint256& hash = tx.GetHash();
-    if (contains(hash))
+    const Txid& hash = tx.GetHash();
+    if (contains(hash.ToUint256()))
         fFound = true;
 
     for (unsigned int i = 0; i < tx.vout.size(); i++)

src/kernel/coinstats.cpp

@@ -89,7 +89,7 @@ static void ApplyCoinHash(std::nullptr_t, const COutPoint& outpoint, const Coin&
 //! construction could cause a previously invalid (and potentially malicious)
 //! UTXO snapshot to be considered valid.
 template <typename T>
-static void ApplyHash(T& hash_obj, const uint256& hash, const std::map<uint32_t, Coin>& outputs)
+static void ApplyHash(T& hash_obj, const Txid& hash, const std::map<uint32_t, Coin>& outputs)
 {
     for (auto it = outputs.begin(); it != outputs.end(); ++it) {
         COutPoint outpoint = COutPoint(hash, it->first);
@@ -118,7 +118,7 @@ static bool ComputeUTXOStats(CCoinsView* view, CCoinsStats& stats, T hash_obj, c
     std::unique_ptr<CCoinsViewCursor> pcursor(view->Cursor());
     assert(pcursor);
 
-    uint256 prevkey;
+    Txid prevkey;
     std::map<uint32_t, Coin> outputs;
     while (pcursor->Valid()) {
         if (interruption_point) interruption_point();

src/node/transaction.cpp

@@ -40,7 +40,7 @@ TransactionError BroadcastTransaction(NodeContext& node, const CTransactionRef t
     assert(node.peerman);
 
     std::promise<void> promise;
-    uint256 txid = tx->GetHash();
+    Txid txid = tx->GetHash();
     uint256 wtxid = tx->GetWitnessHash();
     bool callback_set = false;
 

src/primitives/transaction.cpp

@@ -29,7 +29,7 @@ CTxIn::CTxIn(COutPoint prevoutIn, CScript scriptSigIn, uint32_t nSequenceIn)
     nSequence = nSequenceIn;
 }
 
-CTxIn::CTxIn(uint256 hashPrevTx, uint32_t nOut, CScript scriptSigIn, uint32_t nSequenceIn)
+CTxIn::CTxIn(Txid hashPrevTx, uint32_t nOut, CScript scriptSigIn, uint32_t nSequenceIn)
 {
     prevout = COutPoint(hashPrevTx, nOut);
     scriptSig = scriptSigIn;

src/primitives/transaction.h

@@ -28,13 +28,13 @@
 class COutPoint
 {
 public:
-    uint256 hash;
+    Txid hash;
     uint32_t n;
 
     static constexpr uint32_t NULL_INDEX = std::numeric_limits<uint32_t>::max();
 
     COutPoint(): n(NULL_INDEX) { }
-    COutPoint(const uint256& hashIn, uint32_t nIn): hash(hashIn), n(nIn) { }
+    COutPoint(const Txid& hashIn, uint32_t nIn): hash(hashIn), n(nIn) { }
 
     SERIALIZE_METHODS(COutPoint, obj) { READWRITE(obj.hash, obj.n); }
 
@@ -43,8 +43,7 @@ class COutPoint
 
     friend bool operator<(const COutPoint& a, const COutPoint& b)
     {
-        int cmp = a.hash.Compare(b.hash);
-        return cmp < 0 || (cmp == 0 && a.n < b.n);
+        return std::tie(a.hash, a.n) < std::tie(b.hash, b.n);
     }
 
     friend bool operator==(const COutPoint& a, const COutPoint& b)
@@ -125,7 +124,7 @@ class CTxIn
     }
 
     explicit CTxIn(COutPoint prevoutIn, CScript scriptSigIn=CScript(), uint32_t nSequenceIn=SEQUENCE_FINAL);
-    CTxIn(uint256 hashPrevTx, uint32_t nOut, CScript scriptSigIn=CScript(), uint32_t nSequenceIn=SEQUENCE_FINAL);
+    CTxIn(Txid hashPrevTx, uint32_t nOut, CScript scriptSigIn=CScript(), uint32_t nSequenceIn=SEQUENCE_FINAL);
 
     SERIALIZE_METHODS(CTxIn, obj) { READWRITE(obj.prevout, obj.scriptSig, obj.nSequence); }
 

src/qt/coincontroldialog.cpp

@@ -181,7 +181,7 @@ void CoinControlDialog::showMenu(const QPoint &point)
         if (item->data(COLUMN_ADDRESS, TxHashRole).toString().length() == 64) // transaction hash is 64 characters (this means it is a child node, so it is not a parent node in tree mode)
         {
             m_copy_transaction_outpoint_action->setEnabled(true);
-            if (model->wallet().isLockedCoin(COutPoint(uint256S(item->data(COLUMN_ADDRESS, TxHashRole).toString().toStdString()), item->data(COLUMN_ADDRESS, VOutRole).toUInt())))
+            if (model->wallet().isLockedCoin(COutPoint(TxidFromString(item->data(COLUMN_ADDRESS, TxHashRole).toString().toStdString()), item->data(COLUMN_ADDRESS, VOutRole).toUInt())))
             {
                 lockAction->setEnabled(false);
                 unlockAction->setEnabled(true);
@@ -244,7 +244,7 @@ void CoinControlDialog::lockCoin()
     if (contextMenuItem->checkState(COLUMN_CHECKBOX) == Qt::Checked)
         contextMenuItem->setCheckState(COLUMN_CHECKBOX, Qt::Unchecked);
 
-    COutPoint outpt(uint256S(contextMenuItem->data(COLUMN_ADDRESS, TxHashRole).toString().toStdString()), contextMenuItem->data(COLUMN_ADDRESS, VOutRole).toUInt());
+    COutPoint outpt(TxidFromString(contextMenuItem->data(COLUMN_ADDRESS, TxHashRole).toString().toStdString()), contextMenuItem->data(COLUMN_ADDRESS, VOutRole).toUInt());
     model->wallet().lockCoin(outpt, /* write_to_db = */ true);
     contextMenuItem->setDisabled(true);
     contextMenuItem->setIcon(COLUMN_CHECKBOX, platformStyle->SingleColorIcon(":/icons/lock_closed"));
@@ -254,7 +254,7 @@ void CoinControlDialog::lockCoin()
 // context menu action: unlock coin
 void CoinControlDialog::unlockCoin()
 {
-    COutPoint outpt(uint256S(contextMenuItem->data(COLUMN_ADDRESS, TxHashRole).toString().toStdString()), contextMenuItem->data(COLUMN_ADDRESS, VOutRole).toUInt());
+    COutPoint outpt(TxidFromString(contextMenuItem->data(COLUMN_ADDRESS, TxHashRole).toString().toStdString()), contextMenuItem->data(COLUMN_ADDRESS, VOutRole).toUInt());
     model->wallet().unlockCoin(outpt);
     contextMenuItem->setDisabled(false);
     contextMenuItem->setIcon(COLUMN_CHECKBOX, QIcon());
@@ -346,7 +346,7 @@ void CoinControlDialog::viewItemChanged(QTreeWidgetItem* item, int column)
 {
     if (column == COLUMN_CHECKBOX && item->data(COLUMN_ADDRESS, TxHashRole).toString().length() == 64) // transaction hash is 64 characters (this means it is a child node, so it is not a parent node in tree mode)
     {
-        COutPoint outpt(uint256S(item->data(COLUMN_ADDRESS, TxHashRole).toString().toStdString()), item->data(COLUMN_ADDRESS, VOutRole).toUInt());
+        COutPoint outpt(TxidFromString(item->data(COLUMN_ADDRESS, TxHashRole).toString().toStdString()), item->data(COLUMN_ADDRESS, VOutRole).toUInt());
 
         if (item->checkState(COLUMN_CHECKBOX) == Qt::Unchecked)
             m_coin_control.UnSelect(outpt);

src/rest.cpp

@@ -789,16 +789,14 @@ static bool rest_getutxos(const std::any& context, HTTPRequest* req, const std::
 
         for (size_t i = (fCheckMemPool) ? 1 : 0; i < uriParts.size(); i++)
         {
-            uint256 txid;
             int32_t nOutput;
             std::string strTxid = uriParts[i].substr(0, uriParts[i].find('-'));
             std::string strOutput = uriParts[i].substr(uriParts[i].find('-')+1);
 
             if (!ParseInt32(strOutput, &nOutput) || !IsHex(strTxid))
                 return RESTERR(req, HTTP_BAD_REQUEST, "Parse error");
 
-            txid.SetHex(strTxid);
-            vOutPoints.emplace_back(txid, (uint32_t)nOutput);
+            vOutPoints.emplace_back(TxidFromString(strTxid), (uint32_t)nOutput);
         }
 
         if (vOutPoints.size() > 0)

src/rpc/blockchain.cpp

@@ -1057,7 +1057,7 @@ static RPCHelpMan gettxout()
 
     UniValue ret(UniValue::VOBJ);
 
-    uint256 hash(ParseHashV(request.params[0], "txid"));
+    auto hash{Txid::FromUint256(ParseHashV(request.params[0], "txid"))};
     COutPoint out{hash, request.params[1].getInt<uint32_t>()};
     bool fMempool = true;
     if (!request.params[2].isNull())
@@ -2014,7 +2014,7 @@ bool FindScriptPubKey(std::atomic<int>& scan_progress, const std::atomic<bool>&
         }
         if (count % 256 == 0) {
             // update progress reference every 256 item
-            uint32_t high = 0x100 * *key.hash.begin() + *(key.hash.begin() + 1);
+            uint32_t high = 0x100 * *UCharCast(key.hash.begin()) + *(UCharCast(key.hash.begin()) + 1);
             scan_progress = (int)(high * 100.0 / 65536.0 + 0.5);
         }
         if (needles.count(coin.out.scriptPubKey)) {

src/rpc/mempool.cpp

@@ -633,7 +633,7 @@ static RPCHelpMan gettxspendingprevout()
                                     {"vout", UniValueType(UniValue::VNUM)},
                                 }, /*fAllowNull=*/false, /*fStrict=*/true);
 
-                const uint256 txid(ParseHashO(o, "txid"));
+                const Txid txid = Txid::FromUint256(ParseHashO(o, "txid"));
                 const int nOutput{o.find_value("vout").getInt<int>()};
                 if (nOutput < 0) {
                     throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, vout cannot be negative");

src/rpc/rawtransaction_util.cpp

@@ -34,7 +34,7 @@ void AddInputs(CMutableTransaction& rawTx, const UniValue& inputs_in, std::optio
         const UniValue& input = inputs[idx];
         const UniValue& o = input.get_obj();
 
-        uint256 txid = ParseHashO(o, "txid");
+        Txid txid = Txid::FromUint256(ParseHashO(o, "txid"));
 
         const UniValue& vout_v = o.find_value("vout");
         if (!vout_v.isNum())
@@ -185,7 +185,7 @@ void ParsePrevouts(const UniValue& prevTxsUnival, FillableSigningProvider* keyst
                     {"scriptPubKey", UniValueType(UniValue::VSTR)},
                 });
 
-            uint256 txid = ParseHashO(prevOut, "txid");
+            Txid txid = Txid::FromUint256(ParseHashO(prevOut, "txid"));
 
             int nOut = prevOut.find_value("vout").getInt<int>();
             if (nOut < 0) {

src/rpc/txoutproof.cpp

@@ -69,7 +69,7 @@ static RPCHelpMan gettxoutproof()
 
                 // Loop through txids and try to find which block they're in. Exit loop once a block is found.
                 for (const auto& tx : setTxids) {
-                    const Coin& coin = AccessByTxid(active_chainstate.CoinsTip(), tx);
+                    const Coin& coin = AccessByTxid(active_chainstate.CoinsTip(), Txid::FromUint256(tx));
                     if (!coin.IsSpent()) {
                         pblockindex = active_chainstate.m_chain[coin.nHeight];
                         break;

src/test/blockencodings_tests.cpp

@@ -32,13 +32,13 @@ static CBlock BuildBlockTestCase() {
     block.hashPrevBlock = InsecureRand256();
     block.nBits = 0x207fffff;
 
-    tx.vin[0].prevout.hash = InsecureRand256();
+    tx.vin[0].prevout.hash = Txid::FromUint256(InsecureRand256());
     tx.vin[0].prevout.n = 0;
     block.vtx[1] = MakeTransactionRef(tx);
 
     tx.vin.resize(10);
     for (size_t i = 0; i < tx.vin.size(); i++) {
-        tx.vin[i].prevout.hash = InsecureRand256();
+        tx.vin[i].prevout.hash = Txid::FromUint256(InsecureRand256());
         tx.vin[i].prevout.n = 0;
     }
     block.vtx[2] = MakeTransactionRef(tx);

src/test/bloom_tests.cpp

@@ -136,11 +136,11 @@ BOOST_AUTO_TEST_CASE(bloom_match)
     BOOST_CHECK_MESSAGE(filter.IsRelevantAndUpdate(tx), "Simple Bloom filter didn't match output address");
 
     filter = CBloomFilter(10, 0.000001, 0, BLOOM_UPDATE_ALL);
-    filter.insert(COutPoint(uint256S("0x90c122d70786e899529d71dbeba91ba216982fb6ba58f3bdaab65e73b7e9260b"), 0));
+    filter.insert(COutPoint(TxidFromString("0x90c122d70786e899529d71dbeba91ba216982fb6ba58f3bdaab65e73b7e9260b"), 0));
     BOOST_CHECK_MESSAGE(filter.IsRelevantAndUpdate(tx), "Simple Bloom filter didn't match COutPoint");
 
     filter = CBloomFilter(10, 0.000001, 0, BLOOM_UPDATE_ALL);
-    COutPoint prevOutPoint(uint256S("0x90c122d70786e899529d71dbeba91ba216982fb6ba58f3bdaab65e73b7e9260b"), 0);
+    COutPoint prevOutPoint(TxidFromString("0x90c122d70786e899529d71dbeba91ba216982fb6ba58f3bdaab65e73b7e9260b"), 0);
     {
         std::vector<unsigned char> data(32 + sizeof(unsigned int));
         memcpy(data.data(), prevOutPoint.hash.begin(), 32);
@@ -158,11 +158,11 @@ BOOST_AUTO_TEST_CASE(bloom_match)
     BOOST_CHECK_MESSAGE(!filter.IsRelevantAndUpdate(tx), "Simple Bloom filter matched random address");
 
     filter = CBloomFilter(10, 0.000001, 0, BLOOM_UPDATE_ALL);
-    filter.insert(COutPoint(uint256S("0x90c122d70786e899529d71dbeba91ba216982fb6ba58f3bdaab65e73b7e9260b"), 1));
+    filter.insert(COutPoint(TxidFromString("0x90c122d70786e899529d71dbeba91ba216982fb6ba58f3bdaab65e73b7e9260b"), 1));
     BOOST_CHECK_MESSAGE(!filter.IsRelevantAndUpdate(tx), "Simple Bloom filter matched COutPoint for an output we didn't care about");
 
     filter = CBloomFilter(10, 0.000001, 0, BLOOM_UPDATE_ALL);
-    filter.insert(COutPoint(uint256S("0x000000d70786e899529d71dbeba91ba216982fb6ba58f3bdaab65e73b7e9260b"), 0));
+    filter.insert(COutPoint(TxidFromString("0x000000d70786e899529d71dbeba91ba216982fb6ba58f3bdaab65e73b7e9260b"), 0));
     BOOST_CHECK_MESSAGE(!filter.IsRelevantAndUpdate(tx), "Simple Bloom filter matched COutPoint for an output we didn't care about");
 }
 
@@ -414,9 +414,9 @@ BOOST_AUTO_TEST_CASE(merkle_block_4_test_p2pubkey_only)
     BOOST_CHECK(merkleBlock.header.GetHash() == block.GetHash());
 
     // We should match the generation outpoint
-    BOOST_CHECK(filter.contains(COutPoint(uint256S("0x147caa76786596590baa4e98f5d9f48b86c7765e489f7a6ff3360fe5c674360b"), 0)));
+    BOOST_CHECK(filter.contains(COutPoint(TxidFromString("0x147caa76786596590baa4e98f5d9f48b86c7765e489f7a6ff3360fe5c674360b"), 0)));
     // ... but not the 4th transaction's output (its not pay-2-pubkey)
-    BOOST_CHECK(!filter.contains(COutPoint(uint256S("0x02981fa052f0481dbc5868f4fc2166035a10f27a03cfd2de67326471df5bc041"), 0)));
+    BOOST_CHECK(!filter.contains(COutPoint(TxidFromString("0x02981fa052f0481dbc5868f4fc2166035a10f27a03cfd2de67326471df5bc041"), 0)));
 }
 
 BOOST_AUTO_TEST_CASE(merkle_block_4_test_update_none)
@@ -437,8 +437,8 @@ BOOST_AUTO_TEST_CASE(merkle_block_4_test_update_none)
     BOOST_CHECK(merkleBlock.header.GetHash() == block.GetHash());
 
     // We shouldn't match any outpoints (UPDATE_NONE)
-    BOOST_CHECK(!filter.contains(COutPoint(uint256S("0x147caa76786596590baa4e98f5d9f48b86c7765e489f7a6ff3360fe5c674360b"), 0)));
-    BOOST_CHECK(!filter.contains(COutPoint(uint256S("0x02981fa052f0481dbc5868f4fc2166035a10f27a03cfd2de67326471df5bc041"), 0)));
+    BOOST_CHECK(!filter.contains(COutPoint(TxidFromString("0x147caa76786596590baa4e98f5d9f48b86c7765e489f7a6ff3360fe5c674360b"), 0)));
+    BOOST_CHECK(!filter.contains(COutPoint(TxidFromString("0x02981fa052f0481dbc5868f4fc2166035a10f27a03cfd2de67326471df5bc041"), 0)));
 }
 
 static std::vector<unsigned char> RandomData()

src/test/coins_tests.cpp

@@ -137,16 +137,16 @@ void SimulationTest(CCoinsView* base, bool fake_best_block)
     stack.push_back(std::make_unique<CCoinsViewCacheTest>(base)); // Start with one cache.
 
     // Use a limited set of random transaction ids, so we do test overwriting entries.
-    std::vector<uint256> txids;
+    std::vector<Txid> txids;
     txids.resize(NUM_SIMULATION_ITERATIONS / 8);
     for (unsigned int i = 0; i < txids.size(); i++) {
-        txids[i] = InsecureRand256();
+        txids[i] = Txid::FromUint256(InsecureRand256());
     }
 
     for (unsigned int i = 0; i < NUM_SIMULATION_ITERATIONS; i++) {
         // Do a random modification.
         {
-            uint256 txid = txids[InsecureRandRange(txids.size())]; // txid we're going to modify in this iteration.
+            auto txid = txids[InsecureRandRange(txids.size())]; // txid we're going to modify in this iteration.
             Coin& coin = result[COutPoint(txid, 0)];
 
             // Determine whether to test HaveCoin before or after Access* (or both). As these functions
@@ -290,7 +290,7 @@ UtxoData utxoData;
 
 UtxoData::iterator FindRandomFrom(const std::set<COutPoint> &utxoSet) {
     assert(utxoSet.size());
-    auto utxoSetIt = utxoSet.lower_bound(COutPoint(InsecureRand256(), 0));
+    auto utxoSetIt = utxoSet.lower_bound(COutPoint(Txid::FromUint256(InsecureRand256()), 0));
     if (utxoSetIt == utxoSet.end()) {
         utxoSetIt = utxoSet.begin();
     }
@@ -926,7 +926,7 @@ void TestFlushBehavior(
         }
     };
 
-    uint256 txid = InsecureRand256();
+    Txid txid = Txid::FromUint256(InsecureRand256());
     COutPoint outp = COutPoint(txid, 0);
     Coin coin = MakeCoin();
     // Ensure the coins views haven't seen this coin before.
@@ -1017,7 +1017,7 @@ void TestFlushBehavior(
     // --- Bonus check: ensure that a coin added to the base view via one cache
     //     can be spent by another cache which has never seen it.
     //
-    txid = InsecureRand256();
+    txid = Txid::FromUint256(InsecureRand256());
     outp = COutPoint(txid, 0);
     coin = MakeCoin();
     BOOST_CHECK(!base.HaveCoin(outp));
@@ -1040,7 +1040,7 @@ void TestFlushBehavior(
 
     // --- Bonus check 2: ensure that a FRESH, spent coin is deleted by Sync()
     //
-    txid = InsecureRand256();
+    txid = Txid::FromUint256(InsecureRand256());
     outp = COutPoint(txid, 0);
     coin = MakeCoin();
     CAmount coin_val = coin.out.nValue;