Drop UpdateTransaction in favor of UpdateInput

Updating the input explicitly requires the caller to present a mutable
input, which more clearly communicates the effects and intent of the method.

In most cases, this input is already immediately available and need not be
looked up.

7 files changed, 14 insertions, 21 deletions

diff --git a/src/bitcoin-tx.cpp b/src/bitcoin-tx.cpp
index bf42307df..0814c750d 100644
--- a/src/bitcoin-tx.cpp
+++ b/src/bitcoin-tx.cpp
@@ -629,7 +629,7 @@ static void MutateTxSign(CMutableTransaction& tx, const std::string& flagStr)
 
     // Sign what we can:
     for (unsigned int i = 0; i < mergedTx.vin.size(); i++) {
-        const CTxIn& txin = mergedTx.vin[i];
+        CTxIn& txin = mergedTx.vin[i];
         const Coin& coin = view.AccessCoin(txin.prevout);
         if (coin.IsSpent()) {
             continue;
@@ -644,7 +644,7 @@ static void MutateTxSign(CMutableTransaction& tx, const std::string& flagStr)
 
         // ... and merge in other signatures:
         sigdata = CombineSignatures(prevPubKey, MutableTransactionSignatureChecker(&mergedTx, i, amount), sigdata, DataFromTransaction(txv, i));
-        UpdateTransaction(mergedTx, i, sigdata);
+        UpdateInput(txin, sigdata);
     }
 
     tx = mergedTx;
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index c5185ca59..7d8c8793a 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -748,7 +748,7 @@ static UniValue combinerawtransaction(const JSONRPCRequest& request)
             }
         }
 
-        UpdateTransaction(mergedTx, i, sigdata);
+        UpdateInput(txin, sigdata);
     }
 
     return EncodeHexTx(mergedTx);
@@ -882,7 +882,7 @@ UniValue SignTransaction(CMutableTransaction& mtx, const UniValue& prevTxsUnival
         }
         sigdata = CombineSignatures(prevPubKey, TransactionSignatureChecker(&txConst, i, amount), sigdata, DataFromTransaction(mtx, i));
 
-        UpdateTransaction(mtx, i, sigdata);
+        UpdateInput(txin, sigdata);
 
         ScriptError serror = SCRIPT_ERR_OK;
         if (!VerifyScript(txin.scriptSig, prevPubKey, &txin.scriptWitness, STANDARD_SCRIPT_VERIFY_FLAGS, TransactionSignatureChecker(&txConst, i, amount), &serror)) {
diff --git a/src/script/sign.cpp b/src/script/sign.cpp
index ac35f17f3..35cb80aea 100644
--- a/src/script/sign.cpp
+++ b/src/script/sign.cpp
@@ -199,12 +199,6 @@ void UpdateInput(CTxIn& input, const SignatureData& data)
     input.scriptWitness = data.scriptWitness;
 }
 
-void UpdateTransaction(CMutableTransaction& tx, unsigned int nIn, const SignatureData& data)
-{
-    assert(tx.vin.size() > nIn);
-    UpdateInput(tx.vin[nIn], data);
-}
-
 bool SignSignature(const SigningProvider &provider, const CScript& fromPubKey, CMutableTransaction& txTo, unsigned int nIn, const CAmount& amount, int nHashType)
 {
     assert(nIn < txTo.vin.size());
@@ -214,7 +208,7 @@ bool SignSignature(const SigningProvider &provider, const CScript& fromPubKey, C
 
     SignatureData sigdata;
     bool ret = ProduceSignature(provider, creator, fromPubKey, sigdata);
-    UpdateTransaction(txTo, nIn, sigdata);
+    UpdateInput(txTo.vin.at(nIn), sigdata);
     return ret;
 }
 
diff --git a/src/script/sign.h b/src/script/sign.h
index cf3651c1d..553db0734 100644
--- a/src/script/sign.h
+++ b/src/script/sign.h
@@ -80,7 +80,6 @@ SignatureData CombineSignatures(const CScript& scriptPubKey, const BaseSignature
 
 /** Extract signature data from a transaction, and insert it. */
 SignatureData DataFromTransaction(const CMutableTransaction& tx, unsigned int nIn);
-void UpdateTransaction(CMutableTransaction& tx, unsigned int nIn, const SignatureData& data);
 void UpdateInput(CTxIn& input, const SignatureData& data);
 
 /* Check whether we know how to sign for an output like this, assuming we
diff --git a/src/test/transaction_tests.cpp b/src/test/transaction_tests.cpp
index cc72e96eb..65c5b8ea1 100644
--- a/src/test/transaction_tests.cpp
+++ b/src/test/transaction_tests.cpp
@@ -629,7 +629,7 @@ BOOST_AUTO_TEST_CASE(test_witness)
     CreateCreditAndSpend(keystore2, scriptMulti, output2, input2, false);
     CheckWithFlag(output2, input2, 0, false);
     BOOST_CHECK(*output1 == *output2);
-    UpdateTransaction(input1, 0, CombineSignatures(output1->vout[0].scriptPubKey, MutableTransactionSignatureChecker(&input1, 0, output1->vout[0].nValue), DataFromTransaction(input1, 0), DataFromTransaction(input2, 0)));
+    UpdateInput(input1.vin[0], CombineSignatures(output1->vout[0].scriptPubKey, MutableTransactionSignatureChecker(&input1, 0, output1->vout[0].nValue), DataFromTransaction(input1, 0), DataFromTransaction(input2, 0)));
     CheckWithFlag(output1, input1, STANDARD_SCRIPT_VERIFY_FLAGS, true);
 
     // P2SH 2-of-2 multisig
@@ -640,7 +640,7 @@ BOOST_AUTO_TEST_CASE(test_witness)
     CheckWithFlag(output2, input2, 0, true);
     CheckWithFlag(output2, input2, SCRIPT_VERIFY_P2SH, false);
     BOOST_CHECK(*output1 == *output2);
-    UpdateTransaction(input1, 0, CombineSignatures(output1->vout[0].scriptPubKey, MutableTransactionSignatureChecker(&input1, 0, output1->vout[0].nValue), DataFromTransaction(input1, 0), DataFromTransaction(input2, 0)));
+    UpdateInput(input1.vin[0], CombineSignatures(output1->vout[0].scriptPubKey, MutableTransactionSignatureChecker(&input1, 0, output1->vout[0].nValue), DataFromTransaction(input1, 0), DataFromTransaction(input2, 0)));
     CheckWithFlag(output1, input1, SCRIPT_VERIFY_P2SH, true);
     CheckWithFlag(output1, input1, STANDARD_SCRIPT_VERIFY_FLAGS, true);
 
@@ -652,7 +652,7 @@ BOOST_AUTO_TEST_CASE(test_witness)
     CheckWithFlag(output2, input2, 0, true);
     CheckWithFlag(output2, input2, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS, false);
     BOOST_CHECK(*output1 == *output2);
-    UpdateTransaction(input1, 0, CombineSignatures(output1->vout[0].scriptPubKey, MutableTransactionSignatureChecker(&input1, 0, output1->vout[0].nValue), DataFromTransaction(input1, 0), DataFromTransaction(input2, 0)));
+    UpdateInput(input1.vin[0], CombineSignatures(output1->vout[0].scriptPubKey, MutableTransactionSignatureChecker(&input1, 0, output1->vout[0].nValue), DataFromTransaction(input1, 0), DataFromTransaction(input2, 0)));
     CheckWithFlag(output1, input1, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS, true);
     CheckWithFlag(output1, input1, STANDARD_SCRIPT_VERIFY_FLAGS, true);
 
@@ -664,7 +664,7 @@ BOOST_AUTO_TEST_CASE(test_witness)
     CheckWithFlag(output2, input2, SCRIPT_VERIFY_P2SH, true);
     CheckWithFlag(output2, input2, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS, false);
     BOOST_CHECK(*output1 == *output2);
-    UpdateTransaction(input1, 0, CombineSignatures(output1->vout[0].scriptPubKey, MutableTransactionSignatureChecker(&input1, 0, output1->vout[0].nValue), DataFromTransaction(input1, 0), DataFromTransaction(input2, 0)));
+    UpdateInput(input1.vin[0], CombineSignatures(output1->vout[0].scriptPubKey, MutableTransactionSignatureChecker(&input1, 0, output1->vout[0].nValue), DataFromTransaction(input1, 0), DataFromTransaction(input2, 0)));
     CheckWithFlag(output1, input1, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS, true);
     CheckWithFlag(output1, input1, STANDARD_SCRIPT_VERIFY_FLAGS, true);
 }
diff --git a/src/test/txvalidationcache_tests.cpp b/src/test/txvalidationcache_tests.cpp
index eb23ba5ad..2cd00e212 100644
--- a/src/test/txvalidationcache_tests.cpp
+++ b/src/test/txvalidationcache_tests.cpp
@@ -315,7 +315,7 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
         // Sign
         SignatureData sigdata;
         ProduceSignature(keystore, MutableTransactionSignatureCreator(&valid_with_witness_tx, 0, 11*CENT, SIGHASH_ALL), spend_tx.vout[1].scriptPubKey, sigdata);
-        UpdateTransaction(valid_with_witness_tx, 0, sigdata);
+        UpdateInput(valid_with_witness_tx.vin[0], sigdata);
 
         // This should be valid under all script flags.
         ValidateCheckInputsForAllFlags(valid_with_witness_tx, 0, true);
@@ -343,7 +343,7 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
         for (int i=0; i<2; ++i) {
             SignatureData sigdata;
             ProduceSignature(keystore, MutableTransactionSignatureCreator(&tx, i, 11*CENT, SIGHASH_ALL), spend_tx.vout[i].scriptPubKey, sigdata);
-            UpdateTransaction(tx, i, sigdata);
+            UpdateInput(tx.vin[i], sigdata);
         }
 
         // This should be valid under all script flags
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 74f36e9ab..21f13d21c 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2608,7 +2608,7 @@ bool CWallet::SignTransaction(CMutableTransaction &tx)
     // sign the new tx
     CTransaction txNewConst(tx);
     int nIn = 0;
-    for (const auto& input : tx.vin) {
+    for (auto& input : tx.vin) {
         std::map<uint256, CWalletTx>::const_iterator mi = mapWallet.find(input.prevout.hash);
         if(mi == mapWallet.end() || input.prevout.n >= mi->second.tx->vout.size()) {
             return false;
@@ -2619,7 +2619,7 @@ bool CWallet::SignTransaction(CMutableTransaction &tx)
         if (!ProduceSignature(*this, TransactionSignatureCreator(&txNewConst, nIn, amount, SIGHASH_ALL), scriptPubKey, sigdata)) {
             return false;
         }
-        UpdateTransaction(tx, nIn, sigdata);
+        UpdateInput(input, sigdata);
         nIn++;
     }
     return true;
@@ -3050,7 +3050,7 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CTransac
                     strFailReason = _("Signing transaction failed");
                     return false;
                 } else {
-                    UpdateTransaction(txNew, nIn, sigdata);
+                    UpdateInput(txNew.vin.at(nIn), sigdata);
                 }
 
                 nIn++;