Remove old comment to datacarriersize argument

Credit: Sjors Provoost and Antoine Poinsot

src/test/transaction_tests.cpp

@@ -859,6 +859,9 @@ BOOST_AUTO_TEST_CASE(test_IsStandard)
     CheckIsNotStandard(t, "scriptpubkey");
 
     // TxoutType::NULL_DATA
+    //
+    // Until v30 OP_RETURN was limited to 83 bytes (80 bytes of data, +1 for
+    // OP_RETURN, +2 for the pushdata opcodes). Here we test with 84 bytes.
     t.vout[0].scriptPubKey = CScript() << OP_RETURN << "04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef3804678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef3800"_hex;
     BOOST_CHECK_EQUAL(84, t.vout[0].scriptPubKey.size());
     CheckIsStandard(t);

test/functional/mempool_accept.py

@@ -9,6 +9,7 @@ from decimal import Decimal
 import math
 
 from test_framework.test_framework import BitcoinTestFramework
+from test_framework.blocktools import MAX_STANDARD_TX_WEIGHT
 from test_framework.messages import (
     MAX_BIP125_RBF_SEQUENCE,
     COIN,
@@ -327,6 +328,52 @@ class MempoolAcceptanceTest(BitcoinTestFramework):
             rawtxs=[tx.serialize().hex()],
         )
 
+        # OP_RETURN followed by non-push
+        tx = tx_from_hex(raw_tx_reference)
+        tx.vout[0].scriptPubKey = CScript([OP_RETURN, OP_HASH160])
+        tx.vout = [tx.vout[0]] * 2
+        self.check_mempool_result(
+            result_expected=[{'txid': tx.rehash(), 'allowed': False, 'reject-reason': 'scriptpubkey'}],
+            rawtxs=[tx.serialize().hex()],
+        )
+
+        # Multiple OP_RETURN and more than 83 bytes are standard since v30
+        tx = tx_from_hex(raw_tx_reference)
+        tx.vout.append(CTxOut(0, CScript([OP_RETURN, b'\xff'])))
+        tx.vout.append(CTxOut(0, CScript([OP_RETURN, b'\xff' * 90])))
+
+        self.check_mempool_result(
+            result_expected=[{'txid': tx.rehash(), 'allowed': True, 'vsize': tx.get_vsize(), 'fees': {'base': Decimal('0.05')}}],
+            rawtxs=[tx.serialize().hex()],
+            maxfeerate=0
+        )
+
+        self.log.info("A transaction with several OP_RETURN outputs.")
+        tx = tx_from_hex(raw_tx_reference)
+        op_return_count = 42
+        tx.vout[0].nValue = int(tx.vout[0].nValue / op_return_count)
+        tx.vout[0].scriptPubKey = CScript([OP_RETURN, b'\xff'])
+        tx.vout = [tx.vout[0]] * op_return_count
+        self.check_mempool_result(
+            result_expected=[{"txid": tx.rehash(), "allowed": True, "vsize": tx.get_vsize(), "fees": {"base": Decimal("0.05000026")}}],
+            rawtxs=[tx.serialize().hex()],
+        )
+
+        self.log.info("A transaction with an OP_RETUN output that bumps into the max standardness tx size.")
+        tx = tx_from_hex(raw_tx_reference)
+        tx.vout[0].scriptPubKey = CScript([OP_RETURN])
+        data_len = int(MAX_STANDARD_TX_WEIGHT / 4) - tx.get_vsize() - 5 - 4  # -5 for PUSHDATA4 and -4 for script size
+        tx.vout[0].scriptPubKey = CScript([OP_RETURN, b"\xff" * (data_len)])
+        self.check_mempool_result(
+            result_expected=[{"txid": tx.rehash(), "allowed": True, "vsize": tx.get_vsize(), "fees": {"base": Decimal("0.1") - Decimal("0.05")}}],
+            rawtxs=[tx.serialize().hex()],
+        )
+        tx.vout[0].scriptPubKey = CScript([OP_RETURN, b"\xff" * (data_len + 1)])
+        self.check_mempool_result(
+            result_expected=[{"txid": tx.rehash(), "allowed": False, "reject-reason": "tx-size"}],
+            rawtxs=[tx.serialize().hex()],
+        )
+
         self.log.info('A timelocked transaction')
         tx = tx_from_hex(raw_tx_reference)
         tx.vin[0].nSequence -= 1  # Should be non-max, so locktime is not ignored

test/functional/mining_basic.py

@@ -186,6 +186,9 @@ class MiningTest(BitcoinTestFramework):
             assert tx_below_min_feerate['txid'] not in block_template_txids
             assert tx_below_min_feerate['txid'] not in block_txids
 
+        # Restart node to clear mempool for the next test
+        self.restart_node(0)
+
     def test_timewarp(self):
         self.log.info("Test timewarp attack mitigation (BIP94)")
         node = self.nodes[0]
@@ -279,11 +282,9 @@ class MiningTest(BitcoinTestFramework):
     def test_block_max_weight(self):
         self.log.info("Testing default and custom -blockmaxweight startup options.")
 
-        # Restart the node
         LARGE_TXS_COUNT = 10
         LARGE_VSIZE = int(((MAX_BLOCK_WEIGHT - DEFAULT_BLOCK_RESERVED_WEIGHT) / WITNESS_SCALE_FACTOR) / LARGE_TXS_COUNT)
         HIGH_FEERATE = Decimal("0.0003")
-        self.restart_node(0)
 
         # Ensure the mempool is empty
         assert_equal(len(self.nodes[0].getrawmempool()), 0)

test/functional/test_framework/mempool_util.py

@@ -41,8 +41,8 @@ def fill_mempool(test_framework, node, *, tx_sync_fun=None):
     """Fill mempool until eviction.
 
     Allows for simpler testing of scenarios with floating mempoolminfee > minrelay
-    Requires -datacarriersize=100000 and -maxmempool=5 and assumes -minrelaytxfee
-    is 1 sat/vbyte.
+    Requires -maxmempool=5 and assumes -minrelaytxfee is 1 sat/vbyte.
+
     To avoid unintentional tx dependencies, the mempool filling txs are created with a
     tagged ephemeral miniwallet instance.
     """