Merge bitcoin/bitcoin#19426: refactor: Change * to & in MutableTransactionSignatureCreator

fac6cfc50f65c610f2df9af3ec2efff5eade6661 refactor: Change * to & in MutableTransactionSignatureCreator (MarcoFalke)

Pull request description:

  The `MutableTransactionSignatureCreator` constructor takes in a pointer to a mutable transaction. This is problematic for several reasons:

  * It would be undefined behaviour to pass in a nullptr because for signature creation, the memory of the mutable transaction is accessed
  * No caller currently passes in a nullptr, so passing a reference as a pointer is confusing

  Fix all issues by replacing `*` with `&` in `MutableTransactionSignatureCreator`

ACKs for top commit:
  theStack:
    Code-review ACK fac6cfc50f65c610f2df9af3ec2efff5eade6661
  jonatack:
    ACK fac6cfc50f65c610f2df9af3ec2efff5eade6661

Tree-SHA512: d84296b030bd4fa2709e5adbfe43a5f8377d218957d844af69a819893252af671df7f00004f5ba601a0bd70f3c1c2e58c4f00e75684da663f28432bb5c89fb86

5 files changed, 8 insertions, 8 deletions

diff --git a/src/test/descriptor_tests.cpp b/src/test/descriptor_tests.cpp
index 30add9c16d..63c86a896d 100644
--- a/src/test/descriptor_tests.cpp
+++ b/src/test/descriptor_tests.cpp
@@ -312,7 +312,7 @@ void DoCheck(const std::string& prv, const std::string& pub, const std::string&
                     std::vector<CTxOut> utxos(1);
                     PrecomputedTransactionData txdata;
                     txdata.Init(spend, std::move(utxos), /*force=*/true);
-                    MutableTransactionSignatureCreator creator(&spend, 0, CAmount{0}, &txdata, SIGHASH_DEFAULT);
+                    MutableTransactionSignatureCreator creator{spend, 0, CAmount{0}, &txdata, SIGHASH_DEFAULT};
                     SignatureData sigdata;
                     BOOST_CHECK_MESSAGE(ProduceSignature(Merge(keys_priv, script_provider), creator, spks[n], sigdata), prv);
                 }
diff --git a/src/test/fuzz/script_sign.cpp b/src/test/fuzz/script_sign.cpp
index 1446eafe92..3ddb30d870 100644
--- a/src/test/fuzz/script_sign.cpp
+++ b/src/test/fuzz/script_sign.cpp
@@ -113,7 +113,7 @@ FUZZ_TARGET_INIT(script_sign, initialize_script_sign)
             }
             if (n_in < script_tx_to.vin.size()) {
                 (void)SignSignature(provider, ConsumeScript(fuzzed_data_provider), script_tx_to, n_in, ConsumeMoney(fuzzed_data_provider), fuzzed_data_provider.ConsumeIntegral<int>());
-                MutableTransactionSignatureCreator signature_creator{&tx_to, n_in, ConsumeMoney(fuzzed_data_provider), fuzzed_data_provider.ConsumeIntegral<int>()};
+                MutableTransactionSignatureCreator signature_creator{tx_to, n_in, ConsumeMoney(fuzzed_data_provider), fuzzed_data_provider.ConsumeIntegral<int>()};
                 std::vector<unsigned char> vch_sig;
                 CKeyID address;
                 if (fuzzed_data_provider.ConsumeBool()) {
diff --git a/src/test/script_tests.cpp b/src/test/script_tests.cpp
index c453f22594..19e32d0c36 100644
--- a/src/test/script_tests.cpp
+++ b/src/test/script_tests.cpp
@@ -1162,7 +1162,7 @@ SignatureData CombineSignatures(const CTxOut& txout, const CMutableTransaction&
     SignatureData data;
     data.MergeSignatureData(scriptSig1);
     data.MergeSignatureData(scriptSig2);
-    ProduceSignature(DUMMY_SIGNING_PROVIDER, MutableTransactionSignatureCreator(&tx, 0, txout.nValue, SIGHASH_DEFAULT), txout.scriptPubKey, data);
+    ProduceSignature(DUMMY_SIGNING_PROVIDER, MutableTransactionSignatureCreator(tx, 0, txout.nValue, SIGHASH_DEFAULT), txout.scriptPubKey, data);
     return data;
 }
 
@@ -1796,7 +1796,7 @@ BOOST_AUTO_TEST_CASE(bip341_keypath_test_vectors)
             // Sign and verify signature.
             FlatSigningProvider provider;
             provider.keys[key.GetPubKey().GetID()] = key;
-            MutableTransactionSignatureCreator creator(&tx, txinpos, utxos[txinpos].nValue, &txdata, hashtype);
+            MutableTransactionSignatureCreator creator(tx, txinpos, utxos[txinpos].nValue, &txdata, hashtype);
             std::vector<unsigned char> signature;
             BOOST_CHECK(creator.CreateSchnorrSig(provider, signature, pubkey, nullptr, &merkle_root, SigVersion::TAPROOT));
             BOOST_CHECK_EQUAL(HexStr(signature), input["expected"]["witness"][0].get_str());
diff --git a/src/test/transaction_tests.cpp b/src/test/transaction_tests.cpp
index df67841b66..c3a2a66027 100644
--- a/src/test/transaction_tests.cpp
+++ b/src/test/transaction_tests.cpp
@@ -559,7 +559,7 @@ SignatureData CombineSignatures(const CMutableTransaction& input1, const CMutabl
     SignatureData sigdata;
     sigdata = DataFromTransaction(input1, 0, tx->vout[0]);
     sigdata.MergeSignatureData(DataFromTransaction(input2, 0, tx->vout[0]));
-    ProduceSignature(DUMMY_SIGNING_PROVIDER, MutableTransactionSignatureCreator(&input1, 0, tx->vout[0].nValue, SIGHASH_ALL), tx->vout[0].scriptPubKey, sigdata);
+    ProduceSignature(DUMMY_SIGNING_PROVIDER, MutableTransactionSignatureCreator(input1, 0, tx->vout[0].nValue, SIGHASH_ALL), tx->vout[0].scriptPubKey, sigdata);
     return sigdata;
 }
 
diff --git a/src/test/txvalidationcache_tests.cpp b/src/test/txvalidationcache_tests.cpp
index b1e2119c64..d41b54af20 100644
--- a/src/test/txvalidationcache_tests.cpp
+++ b/src/test/txvalidationcache_tests.cpp
@@ -329,7 +329,7 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, Dersig100Setup)
 
         // Sign
         SignatureData sigdata;
-        BOOST_CHECK(ProduceSignature(keystore, MutableTransactionSignatureCreator(&valid_with_witness_tx, 0, 11*CENT, SIGHASH_ALL), spend_tx.vout[1].scriptPubKey, sigdata));
+        BOOST_CHECK(ProduceSignature(keystore, MutableTransactionSignatureCreator(valid_with_witness_tx, 0, 11 * CENT, SIGHASH_ALL), spend_tx.vout[1].scriptPubKey, sigdata));
         UpdateInput(valid_with_witness_tx.vin[0], sigdata);
 
         // This should be valid under all script flags.
@@ -355,9 +355,9 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, Dersig100Setup)
         tx.vout[0].scriptPubKey = p2pk_scriptPubKey;
 
         // Sign
-        for (int i=0; i<2; ++i) {
+        for (int i = 0; i < 2; ++i) {
             SignatureData sigdata;
-            BOOST_CHECK(ProduceSignature(keystore, MutableTransactionSignatureCreator(&tx, i, 11*CENT, SIGHASH_ALL), spend_tx.vout[i].scriptPubKey, sigdata));
+            BOOST_CHECK(ProduceSignature(keystore, MutableTransactionSignatureCreator(tx, i, 11 * CENT, SIGHASH_ALL), spend_tx.vout[i].scriptPubKey, sigdata));
             UpdateInput(tx.vin[i], sigdata);
         }