Merge bitcoin/bitcoin#32304: test: test MAX_SCRIPT_SIZE for block validity

b1ea542 test: test MAX_SCRIPT_SIZE for block validity (Greg Sanders)

Pull request description:

  I don't believe there are direct tests for this.

ACKs for top commit:
  achow101:
    ACK b1ea542
  TheCharlatan:
    ACK b1ea542
  theStack:
    ACK b1ea542

Tree-SHA512: 1d7d3eab9c54977844bf2ca1aa403b070aae0f818db2fb5cae367d1c4d12f1e403b6fdec224af769a2ebb648cbca8bfd0d7df5db2a89fccf256c9c244484eba2

Author: achow101

test/functional/feature_block.py

@@ -30,6 +30,7 @@
 from test_framework.script import (
     CScript,
     MAX_SCRIPT_ELEMENT_SIZE,
+    MAX_SCRIPT_SIZE,
     OP_2DUP,
     OP_CHECKMULTISIG,
     OP_CHECKMULTISIGVERIFY,
@@ -52,6 +53,7 @@
 from test_framework.util import (
     assert_equal,
     assert_greater_than,
+    assert_raises_rpc_error,
 )
 from test_framework.wallet_util import generate_keypair
 from data import invalid_txs
@@ -112,10 +114,20 @@ def run_test(self):
         b_dup_cb = self.update_block('dup_cb', [])
         self.send_blocks([b_dup_cb])
 
-        b0 = self.next_block(0)
+        # Add gigantic boundary scripts that respect all other limits
+        max_valid_script = CScript([b'\x01' * MAX_SCRIPT_ELEMENT_SIZE] * 19 + [b'\x01' * 62])
+        assert_equal(len(max_valid_script), MAX_SCRIPT_SIZE)
+        min_invalid_script = CScript([b'\x01' * MAX_SCRIPT_ELEMENT_SIZE] * 19 + [b'\x01' * 63])
+        assert_equal(len(min_invalid_script), MAX_SCRIPT_SIZE + 1)
+
+        b0 = self.next_block(0, additional_output_scripts=[max_valid_script, min_invalid_script])
         self.save_spendable_output()
         self.send_blocks([b0])
 
+        # Will test spending once possibly-mature
+        max_size_spendable_output = CTxIn(COutPoint(b0.vtx[0].sha256, 1))
+        min_size_unspendable_output = CTxIn(COutPoint(b0.vtx[0].sha256, 2))
+
         # These constants chosen specifically to trigger an immature coinbase spend
         # at a certain time below.
         NUM_BUFFER_BLOCKS_TO_GENERATE = 99
@@ -128,6 +140,19 @@ def run_test(self):
             self.save_spendable_output()
         self.send_blocks(blocks)
 
+        # MAX_SCRIPT_SIZE testing now that coins are mature
+        tx = CTransaction()
+        tx.vin.append(max_size_spendable_output)
+        tx.vout.append(CTxOut(0, CScript([])))
+        block = self.generateblock(self.nodes[0], output="raw(55)", transactions=[tx.serialize().hex()])
+        assert_equal(block["hash"], self.nodes[0].getbestblockhash())
+        self.nodes[0].invalidateblock(block["hash"])
+        assert_equal(self.nodes[0].getrawmempool(), [])
+
+        # MAX_SCRIPT_SIZE + 1 wasn't added to the utxo set
+        tx.vin[0] = min_size_unspendable_output
+        assert_raises_rpc_error(-25, f'TestBlockValidity failed: bad-txns-inputs-missingorspent, CheckTxInputs: inputs missing/spent in transaction {tx.rehash()}', self.generateblock, self.nodes[0],  output="raw(55)", transactions=[tx.serialize().hex()])
+
         # collect spendable outputs now to avoid cluttering the code later on
         out = []
         for _ in range(NUM_OUTPUTS_TO_COLLECT):
@@ -1358,9 +1383,11 @@ def create_and_sign_transaction(self, spend_tx, value, output_script=None):
         tx.rehash()
         return tx
 
-    def next_block(self, number, spend=None, additional_coinbase_value=0, *, script=None, version=4):
+    def next_block(self, number, spend=None, additional_coinbase_value=0, *, script=None, version=4, additional_output_scripts=None):
         if script is None:
             script = CScript([OP_TRUE])
+        if additional_output_scripts is None:
+            additional_output_scripts = []
         if self.tip is None:
             base_block_hash = self.genesis_hash
             block_time = int(time.time()) + 1
@@ -1371,6 +1398,8 @@ def next_block(self, number, spend=None, additional_coinbase_value=0, *, script=
         height = self.block_heights[base_block_hash] + 1
         coinbase = create_coinbase(height, self.coinbase_pubkey)
         coinbase.vout[0].nValue += additional_coinbase_value
+        for additional_script in additional_output_scripts:
+            coinbase.vout.append(CTxOut(0, additional_script))
         coinbase.rehash()
         if spend is None:
             block = create_block(base_block_hash, coinbase, block_time, version=version)

test/functional/test_framework/script.py

@@ -23,6 +23,7 @@
 from .crypto.ripemd160 import ripemd160
 
 MAX_SCRIPT_ELEMENT_SIZE = 520
+MAX_SCRIPT_SIZE = 10000
 MAX_PUBKEYS_PER_MULTI_A = 999
 LOCKTIME_THRESHOLD = 500000000
 ANNEX_TAG = 0x50