Merge #20916: rpc: Return wtxid from testmempoolaccept

fa0aa87071eaec8a5df17774cdb352195e5e09de rpc: Return wtxid from testmempoolaccept (MarcoFalke)

Pull request description:

  It would be nice if `testmempoolaccept` returned the unique wtxid directly to avoid a costly `decoderawtransaction` roundtrip

ACKs for top commit:
  mjdietzx:
    utACK fa0aa87071eaec8a5df17774cdb352195e5e09de
  stackman27:
    utACK [`fa0aa87`](https://github.com/bitcoin/bitcoin/pull/20916/commits/fa0aa87071eaec8a5df17774cdb352195e5e09de)
  glozow:
    cr ACK https://github.com/bitcoin/bitcoin/pull/20916/commits/fa0aa87071eaec8a5df17774cdb352195e5e09de

Tree-SHA512: 05dbaf46d93e47e9eedb725c2f57175e6d4e1722da0531fe4f80e74fc2518911da87634f25f61fa2bc8d87a3017e82fd0684b09a0a9706d71deed970035c2e7a

7 files changed, 48 insertions, 10 deletions

diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index e2897549b5..e94d554e3c 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -894,6 +894,7 @@ static RPCHelpMan testmempoolaccept()
                         {RPCResult::Type::OBJ, "", "",
                         {
                             {RPCResult::Type::STR_HEX, "txid", "The transaction hash in hex"},
+                            {RPCResult::Type::STR_HEX, "wtxid", "The transaction witness hash in hex"},
                             {RPCResult::Type::BOOL, "allowed", "If the mempool allows this tx to be inserted"},
                             {RPCResult::Type::NUM, "vsize", "Virtual transaction size as defined in BIP 141. This is different from actual serialized size for witness transactions as witness data is discounted (only present when 'allowed' is true)"},
                             {RPCResult::Type::OBJ, "fees", "Transaction fees (only present if 'allowed' is true)",
@@ -930,7 +931,6 @@ static RPCHelpMan testmempoolaccept()
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed. Make sure the tx has at least one input.");
     }
     CTransactionRef tx(MakeTransactionRef(std::move(mtx)));
-    const uint256& tx_hash = tx->GetHash();
 
     const CFeeRate max_raw_tx_fee_rate = request.params[1].isNull() ?
                                              DEFAULT_MAX_RAW_TX_FEE_RATE :
@@ -942,7 +942,8 @@ static RPCHelpMan testmempoolaccept()
 
     UniValue result(UniValue::VARR);
     UniValue result_0(UniValue::VOBJ);
-    result_0.pushKV("txid", tx_hash.GetHex());
+    result_0.pushKV("txid", tx->GetHash().GetHex());
+    result_0.pushKV("wtxid", tx->GetWitnessHash().GetHex());
 
     TxValidationState state;
     bool test_accept_res;
diff --git a/test/functional/feature_cltv.py b/test/functional/feature_cltv.py
index aad255c4a9..b7c2887ee8 100755
--- a/test/functional/feature_cltv.py
+++ b/test/functional/feature_cltv.py
@@ -126,8 +126,13 @@ class BIP65Test(BitcoinTestFramework):
         # First we show that this tx is valid except for CLTV by getting it
         # rejected from the mempool for exactly that reason.
         assert_equal(
-            [{'txid': spendtx.hash, 'allowed': False, 'reject-reason': 'non-mandatory-script-verify-flag (Negative locktime)'}],
-            self.nodes[0].testmempoolaccept(rawtxs=[spendtx.serialize().hex()], maxfeerate=0)
+            [{
+                'txid': spendtx.hash,
+                'wtxid': spendtx.getwtxid(),
+                'allowed': False,
+                'reject-reason': 'non-mandatory-script-verify-flag (Negative locktime)',
+            }],
+            self.nodes[0].testmempoolaccept(rawtxs=[spendtx.serialize().hex()], maxfeerate=0),
         )
 
         # Now we verify that a block with this transaction is also invalid.
diff --git a/test/functional/feature_dersig.py b/test/functional/feature_dersig.py
index 3f7efdbded..3b430139b1 100755
--- a/test/functional/feature_dersig.py
+++ b/test/functional/feature_dersig.py
@@ -112,8 +112,13 @@ class BIP66Test(BitcoinTestFramework):
         # First we show that this tx is valid except for DERSIG by getting it
         # rejected from the mempool for exactly that reason.
         assert_equal(
-            [{'txid': spendtx.hash, 'allowed': False, 'reject-reason': 'non-mandatory-script-verify-flag (Non-canonical DER signature)'}],
-            self.nodes[0].testmempoolaccept(rawtxs=[spendtx.serialize().hex()], maxfeerate=0)
+            [{
+                'txid': spendtx.hash,
+                'wtxid': spendtx.getwtxid(),
+                'allowed': False,
+                'reject-reason': 'non-mandatory-script-verify-flag (Non-canonical DER signature)',
+            }],
+            self.nodes[0].testmempoolaccept(rawtxs=[spendtx.serialize().hex()], maxfeerate=0),
         )
 
         # Now we verify that a block with this transaction is also invalid.
diff --git a/test/functional/mempool_accept.py b/test/functional/mempool_accept.py
index fc4c775668..c4002f524a 100755
--- a/test/functional/mempool_accept.py
+++ b/test/functional/mempool_accept.py
@@ -51,6 +51,8 @@ class MempoolAcceptanceTest(BitcoinTestFramework):
     def check_mempool_result(self, result_expected, *args, **kwargs):
         """Wrapper to check result of testmempoolaccept on node_0's mempool"""
         result_test = self.nodes[0].testmempoolaccept(*args, **kwargs)
+        for r in result_test:
+            r.pop('wtxid')  # Skip check for now
         assert_equal(result_expected, result_test)
         assert_equal(self.nodes[0].getmempoolinfo()['size'], self.mempool_size)  # Must not change mempool state
 
diff --git a/test/functional/p2p_segwit.py b/test/functional/p2p_segwit.py
index a9d8b12d70..54891b07e1 100755
--- a/test/functional/p2p_segwit.py
+++ b/test/functional/p2p_segwit.py
@@ -686,13 +686,35 @@ class SegWitTest(BitcoinTestFramework):
         if not self.segwit_active:
             # Just check mempool acceptance, but don't add the transaction to the mempool, since witness is disallowed
             # in blocks and the tx is impossible to mine right now.
-            assert_equal(self.nodes[0].testmempoolaccept([tx3.serialize_with_witness().hex()]), [{'txid': tx3.hash, 'allowed': True, 'vsize': tx3.get_vsize(), 'fees': { 'base': Decimal('0.00001000')}}])
+            assert_equal(
+                self.nodes[0].testmempoolaccept([tx3.serialize_with_witness().hex()]),
+                [{
+                    'txid': tx3.hash,
+                    'wtxid': tx3.getwtxid(),
+                    'allowed': True,
+                    'vsize': tx3.get_vsize(),
+                    'fees': {
+                        'base': Decimal('0.00001000'),
+                    },
+                }],
+            )
             # Create the same output as tx3, but by replacing tx
             tx3_out = tx3.vout[0]
             tx3 = tx
             tx3.vout = [tx3_out]
             tx3.rehash()
-            assert_equal(self.nodes[0].testmempoolaccept([tx3.serialize_with_witness().hex()]), [{'txid': tx3.hash, 'allowed': True, 'vsize': tx3.get_vsize(), 'fees': { 'base': Decimal('0.00011000')}}])
+            assert_equal(
+                self.nodes[0].testmempoolaccept([tx3.serialize_with_witness().hex()]),
+                [{
+                    'txid': tx3.hash,
+                    'wtxid': tx3.getwtxid(),
+                    'allowed': True,
+                    'vsize': tx3.get_vsize(),
+                    'fees': {
+                        'base': Decimal('0.00011000'),
+                    },
+                }],
+            )
         test_transaction_acceptance(self.nodes[0], self.test_node, tx3, with_witness=True, accepted=True)
 
         self.nodes[0].generate(1)
diff --git a/test/functional/test_framework/messages.py b/test/functional/test_framework/messages.py
index bab4ad0008..6ad4e13db2 100755
--- a/test/functional/test_framework/messages.py
+++ b/test/functional/test_framework/messages.py
@@ -564,6 +564,9 @@ class CTransaction:
     def serialize(self):
         return self.serialize_with_witness()
 
+    def getwtxid(self):
+        return hash256(self.serialize())[::-1].hex()
+
     # Recalculate the txid (transaction hash without witness)
     def rehash(self):
         self.sha256 = None
@@ -579,7 +582,7 @@ class CTransaction:
 
         if self.sha256 is None:
             self.sha256 = uint256_from_str(hash256(self.serialize_without_witness()))
-        self.hash = encode(hash256(self.serialize_without_witness())[::-1], 'hex_codec').decode('ascii')
+        self.hash = hash256(self.serialize_without_witness())[::-1].hex()
 
     def is_valid(self):
         self.calc_sha256()
diff --git a/test/functional/test_framework/wallet.py b/test/functional/test_framework/wallet.py
index 7cb74bdcb3..edd7792608 100644
--- a/test/functional/test_framework/wallet.py
+++ b/test/functional/test_framework/wallet.py
@@ -76,4 +76,4 @@ class MiniWallet:
         from_node.sendrawtransaction(tx_hex)
         assert_equal(tx_info['vsize'], vsize)
         assert_equal(tx_info['fees']['base'], fee)
-        return {'txid': tx_info['txid'], 'wtxid': from_node.decoderawtransaction(tx_hex)['hash'], 'hex': tx_hex}
+        return {'txid': tx_info['txid'], 'wtxid': tx_info['wtxid'], 'hex': tx_hex}