Merge bitcoin/bitcoin#29120: test: Add test case for spending bare multisig

e504b1f test: Add test case for spending bare multisig (Brandon Odiwuor)

Pull request description:

  Fixes bitcoin/bitcoin#29113

ACKs for top commit:
  ajtowns:
    ACK e504b1f ; LGTM and just checking the 1-of-3 case seems fine
  maflcko:
    utACK e504b1f
  achow101:
    ACK e504b1f
  willcl-ark:
    reACK e504b1f

Tree-SHA512: 641a12599efa34e1a3eb65b125318df326628fef3e6886410ea9e63a044664fad7bcad46d1d6f41ddc59630746b9963cedb569c2682b5940b32b9225883da8f2

Author: achow101

src/init.cpp

@@ -634,7 +634,7 @@ void SetupServerArgs(ArgsManager& argsman)
                              MAX_OP_RETURN_RELAY),
                    ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
     argsman.AddArg("-mempoolfullrbf", strprintf("Accept transaction replace-by-fee without requiring replaceability signaling (default: %u)", DEFAULT_MEMPOOL_FULL_RBF), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
-    argsman.AddArg("-permitbaremultisig", strprintf("Relay non-P2SH multisig (default: %u)", DEFAULT_PERMIT_BAREMULTISIG), ArgsManager::ALLOW_ANY,
+    argsman.AddArg("-permitbaremultisig", strprintf("Relay transactions creating non-P2SH multisig outputs (default: %u)", DEFAULT_PERMIT_BAREMULTISIG), ArgsManager::ALLOW_ANY,
                    OptionsCategory::NODE_RELAY);
     argsman.AddArg("-minrelaytxfee=<amt>", strprintf("Fees (in %s/kvB) smaller than this are considered zero fee for relaying, mining and transaction creation (default: %s)",
         CURRENCY_UNIT, FormatMoney(DEFAULT_MIN_RELAY_TX_FEE)), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);

test/functional/mempool_accept.py

@@ -28,6 +28,8 @@
     OP_HASH160,
     OP_RETURN,
     OP_TRUE,
+    SIGHASH_ALL,
+    sign_input_legacy,
 )
 from test_framework.script_util import (
     DUMMY_MIN_OP_RETURN_SCRIPT,
@@ -386,5 +388,24 @@ def run_test(self):
             maxfeerate=0,
         )
 
+        self.log.info('Spending a confirmed bare multisig is okay')
+        address = self.wallet.get_address()
+        tx = tx_from_hex(raw_tx_reference)
+        privkey, pubkey = generate_keypair()
+        tx.vout[0].scriptPubKey = keys_to_multisig_script([pubkey] * 3, k=1)  # Some bare multisig script (1-of-3)
+        tx.rehash()
+        self.generateblock(node, address, [tx.serialize().hex()])
+        tx_spend = CTransaction()
+        tx_spend.vin.append(CTxIn(COutPoint(tx.sha256, 0), b""))
+        tx_spend.vout.append(CTxOut(tx.vout[0].nValue - int(fee*COIN), script_to_p2wsh_script(CScript([OP_TRUE]))))
+        tx_spend.rehash()
+        sign_input_legacy(tx_spend, 0, tx.vout[0].scriptPubKey, privkey, sighash_type=SIGHASH_ALL)
+        tx_spend.vin[0].scriptSig = bytes(CScript([OP_0])) + tx_spend.vin[0].scriptSig
+        self.check_mempool_result(
+            result_expected=[{'txid': tx_spend.rehash(), 'allowed': True, 'vsize': tx_spend.get_vsize(), 'fees': { 'base': Decimal('0.00000700')}}],
+            rawtxs=[tx_spend.serialize().hex()],
+            maxfeerate=0,
+        )
+
 if __name__ == '__main__':
     MempoolAcceptanceTest().main()