Make CMutableTransaction constructor explicit

Silently converting to a CMutableTransaction will drop all caches
and should thus be done explicitly

src/bitcoin-tx.cpp

@@ -548,7 +548,7 @@ static void MutateTxSign(CMutableTransaction& tx, const std::string& flagStr)
     // mergedTx will end up with all the signatures; it
     // starts as a clone of the raw tx:
     CMutableTransaction mergedTx{tx};
-    const CTransaction txv{tx};
+    const CMutableTransaction txv{tx};
     CCoinsView viewDummy;
     CCoinsViewCache view(&viewDummy);
 

src/primitives/transaction.h

@@ -367,7 +367,7 @@ struct CMutableTransaction
     uint32_t nLockTime;
 
     CMutableTransaction();
-    CMutableTransaction(const CTransaction& tx);
+    explicit CMutableTransaction(const CTransaction& tx);
 
     template <typename Stream>
     inline void Serialize(Stream& s) const {

src/test/coins_tests.cpp

@@ -312,7 +312,7 @@ BOOST_AUTO_TEST_CASE(updatecoins_simulation_test)
                 if (InsecureRandRange(10) == 0 && coinbase_coins.size()) {
                     auto utxod = FindRandomFrom(coinbase_coins);
                     // Reuse the exact same coinbase
-                    tx = std::get<0>(utxod->second);
+                    tx = CMutableTransaction{std::get<0>(utxod->second)};
                     // shouldn't be available for reconnection if it's been duplicated
                     disconnected_coins.erase(utxod->first);
 
@@ -331,7 +331,7 @@ BOOST_AUTO_TEST_CASE(updatecoins_simulation_test)
                 // 1/20 times reconnect a previously disconnected tx
                 if (randiter % 20 == 2 && disconnected_coins.size()) {
                     auto utxod = FindRandomFrom(disconnected_coins);
-                    tx = std::get<0>(utxod->second);
+                    tx = CMutableTransaction{std::get<0>(utxod->second)};
                     prevout = tx.vin[0].prevout;
                     if (!CTransaction(tx).IsCoinBase() && !utxoset.count(prevout)) {
                         disconnected_coins.erase(utxod->first);

src/test/script_tests.cpp

@@ -135,7 +135,7 @@ CMutableTransaction BuildCreditingTransaction(const CScript& scriptPubKey, int n
     return txCredit;
 }
 
-CMutableTransaction BuildSpendingTransaction(const CScript& scriptSig, const CScriptWitness& scriptWitness, const CMutableTransaction& txCredit)
+CMutableTransaction BuildSpendingTransaction(const CScript& scriptSig, const CScriptWitness& scriptWitness, const CTransaction& txCredit)
 {
     CMutableTransaction txSpend;
     txSpend.nVersion = 1;
@@ -161,7 +161,7 @@ void DoTest(const CScript& scriptPubKey, const CScript& scriptSig, const CScript
         flags |= SCRIPT_VERIFY_WITNESS;
     }
     ScriptError err;
-    CMutableTransaction txCredit = BuildCreditingTransaction(scriptPubKey, nValue);
+    const CTransaction txCredit{BuildCreditingTransaction(scriptPubKey, nValue)};
     CMutableTransaction tx = BuildSpendingTransaction(scriptSig, scriptWitness, txCredit);
     CMutableTransaction tx2 = tx;
     BOOST_CHECK_MESSAGE(VerifyScript(scriptSig, scriptPubKey, &scriptWitness, flags, MutableTransactionSignatureChecker(&tx, 0, txCredit.vout[0].nValue), &err) == expect, message);
@@ -1071,7 +1071,7 @@ BOOST_AUTO_TEST_CASE(script_CHECKMULTISIG12)
     CScript scriptPubKey12;
     scriptPubKey12 << OP_1 << ToByteVector(key1.GetPubKey()) << ToByteVector(key2.GetPubKey()) << OP_2 << OP_CHECKMULTISIG;
 
-    CMutableTransaction txFrom12 = BuildCreditingTransaction(scriptPubKey12);
+    const CTransaction txFrom12{BuildCreditingTransaction(scriptPubKey12)};
     CMutableTransaction txTo12 = BuildSpendingTransaction(CScript(), CScriptWitness(), txFrom12);
 
     CScript goodsig1 = sign_multisig(scriptPubKey12, key1, txTo12);
@@ -1102,7 +1102,7 @@ BOOST_AUTO_TEST_CASE(script_CHECKMULTISIG23)
     CScript scriptPubKey23;
     scriptPubKey23 << OP_2 << ToByteVector(key1.GetPubKey()) << ToByteVector(key2.GetPubKey()) << ToByteVector(key3.GetPubKey()) << OP_3 << OP_CHECKMULTISIG;
 
-    CMutableTransaction txFrom23 = BuildCreditingTransaction(scriptPubKey23);
+    const CTransaction txFrom23{BuildCreditingTransaction(scriptPubKey23)};
     CMutableTransaction txTo23 = BuildSpendingTransaction(CScript(), CScriptWitness(), txFrom23);
 
     std::vector<CKey> keys;

src/test/txvalidationcache_tests.cpp

@@ -24,7 +24,7 @@ bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsVi
 BOOST_AUTO_TEST_SUITE(tx_validationcache_tests)
 
 static bool
-ToMemPool(CMutableTransaction& tx)
+ToMemPool(const CMutableTransaction& tx)
 {
     LOCK(cs_main);
 

src/wallet/feebumper.cpp

@@ -185,7 +185,7 @@ Result CreateTransaction(const CWallet* wallet, const uint256& txid, const CCoin
     // If the output is not large enough to pay the fee, fail.
     CAmount nDelta = new_fee - old_fee;
     assert(nDelta > 0);
-    mtx =  *wtx.tx;
+    mtx = CMutableTransaction{*wtx.tx};
     CTxOut* poutput = &(mtx.vout[nOutput]);
     if (poutput->nValue < nDelta) {
         errors.push_back("Change output is too small to bump the fee");

src/wallet/wallet.cpp

@@ -2065,8 +2065,8 @@ bool CWalletTx::IsTrusted() const
 
 bool CWalletTx::IsEquivalentTo(const CWalletTx& _tx) const
 {
-        CMutableTransaction tx1 = *this->tx;
-        CMutableTransaction tx2 = *_tx.tx;
+        CMutableTransaction tx1 {*this->tx};
+        CMutableTransaction tx2 {*_tx.tx};
         for (auto& txin : tx1.vin) txin.scriptSig = CScript();
         for (auto& txin : tx2.vin) txin.scriptSig = CScript();
         return CTransaction(tx1) == CTransaction(tx2);