test: add unit test for non-standard bare multisig txs

The function IsStandardTx() returns rejection reason "bare-multisig" if the
transaction has a bare multisig output and the policy flag fIsBareMultisigStd
is false (set by the boolean command-line argument "-permitbaremultisig" -- for
the unit test, we simply set the global flag variable directly).

Author: theStack

src/test/transaction_tests.cpp

@@ -797,6 +797,17 @@ BOOST_AUTO_TEST_CASE(test_IsStandard)
     reason.clear();
     BOOST_CHECK(!IsStandardTx(CTransaction(t), reason));
     BOOST_CHECK_EQUAL(reason, "scriptsig-size");
+
+    // Check bare multisig (standard if policy flag fIsBareMultisigStd is set)
+    fIsBareMultisigStd = true;
+    t.vout[0].scriptPubKey = GetScriptForMultisig(1, {key.GetPubKey()}); // simple 1-of-1
+    t.vin[0].scriptSig = CScript() << std::vector<unsigned char>(65, 0);
+    BOOST_CHECK(IsStandardTx(CTransaction(t), reason));
+
+    fIsBareMultisigStd = false;
+    reason.clear();
+    BOOST_CHECK(!IsStandardTx(CTransaction(t), reason));
+    BOOST_CHECK_EQUAL(reason, "bare-multisig");
 }
 
 BOOST_AUTO_TEST_SUITE_END()