I think the only place we currently test that spending a bare multisig utxo is okay is in AreInputsStandard in script_p2sh_tests.cpp, but this only checks that AreInputsStandard() passes, it doesn't check that there isn't some other rule preventing the spend from entering the mempool and eventually being mined.
Adding
self.log.info('Spending a confirmed bare multisig is okay')
node = self.nodes[0]
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,
)
at the end of mempool_accept.py might therefore be a reasonable addition?
Can add a bug to trigger test failures via:
--- a/src/policy/policy.cpp
+++ b/src/policy/policy.cpp
@@ -185,6 +185,7 @@ bool AreInputsStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs)
std::vector<std::vector<unsigned char> > vSolutions;
TxoutType whichType = Solver(prev.scriptPubKey, vSolutions);
+ if (whichType == TxoutType::MULTISIG) return false;
if (whichType == TxoutType::NONSTANDARD || whichType == TxoutType::WITNESS_UNKNOWN) {
// WITNESS_UNKNOWN failures are typically also caught with a policy
// flag in the script interpreter, but it can be helpful to catch
