Merge #17532: test: add functional test for non-standard txs with too large scriptSig

8f2d773 test: add functional test for non-standard txs with too large scriptSig (Sebastian Falbesoner)

Pull request description:

  Approaches another missing functional test of issue #17394 (counterpart to unit test in PR #17480, Commit bitcoin/bitcoin@5e8a563): A transaction is rejected by the mempool with reason `"scriptsig-size"` if any of the inputs' scriptSig is larger than 1650 bytes.

ACKs for top commit:
  MarcoFalke:
    ACK 8f2d773
  instagibbs:
    ACK bitcoin/bitcoin@8f2d773

Tree-SHA512: 7a45b8a4181158be3e3b91756783ddf032f132ca8780dc35fac91b2df2149268f784d28ac56005135c4d86a357c57805c5a54b8155f0d049932844b18dc03992

Author: fanquake

test/functional/mempool_accept.py

@@ -267,6 +267,12 @@ def run_test(self):
             rawtxs=[tx.serialize().hex()],
         )
         tx.deserialize(BytesIO(hex_str_to_bytes(raw_tx_reference)))
+        tx.vin[0].scriptSig = CScript([b'a' * 1648]) # Some too large scriptSig (>1650 bytes)
+        self.check_mempool_result(
+            result_expected=[{'txid': tx.rehash(), 'allowed': False, 'reject-reason': 'scriptsig-size'}],
+            rawtxs=[tx.serialize().hex()],
+        )
+        tx.deserialize(BytesIO(hex_str_to_bytes(raw_tx_reference)))
         output_p2sh_burn = CTxOut(nValue=540, scriptPubKey=CScript([OP_HASH160, hash160(b'burn'), OP_EQUAL]))
         num_scripts = 100000 // len(output_p2sh_burn.serialize())  # Use enough outputs to make the tx too large for our policy
         tx.vout = [output_p2sh_burn] * num_scripts