From f6fa0c06b896e06edecf03cabbbc43db1df3e62b Mon Sep 17 00:00:00 2001
From: Kittywhiskers Van Gogh <63189531+kwvg@users.noreply.github.com>
Date: Thu, 26 Sep 2024 22:11:51 +0000
Subject: [PATCH] merge bitcoin#23501: various feature_nulldummy.py
 improvements

---
 test/functional/feature_nulldummy.py | 32 +++++++++++-----------------
 1 file changed, 13 insertions(+), 19 deletions(-)

diff --git a/test/functional/feature_nulldummy.py b/test/functional/feature_nulldummy.py
index ecae987613..dd8c3e0ca4 100755
--- a/test/functional/feature_nulldummy.py
+++ b/test/functional/feature_nulldummy.py
@@ -20,7 +20,10 @@ from test_framework.blocktools import (
     create_transaction,
 )
 from test_framework.messages import CTransaction
-from test_framework.script import CScript
+from test_framework.script import (
+    OP_0,
+    OP_TRUE,
+)
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_equal,
@@ -29,16 +32,12 @@ from test_framework.util import (
 
 NULLDUMMY_ERROR = "non-mandatory-script-verify-flag (Dummy CHECKMULTISIG argument must be zero)"
 
-def trueDummy(tx):
-    scriptSig = CScript(tx.vin[0].scriptSig)
-    newscript = []
-    for i in scriptSig:
-        if len(newscript) == 0:
-            assert len(i) == 0
-            newscript.append(b'\x51')
-        else:
-            newscript.append(i)
-    tx.vin[0].scriptSig = CScript(newscript)
+
+def invalidate_nulldummy_tx(tx):
+    """Transform a NULLDUMMY compliant tx (i.e. scriptSig starts with OP_0)
+    to be non-NULLDUMMY compliant by replacing the dummy with OP_TRUE"""
+    assert_equal(tx.vin[0].scriptSig[0], OP_0)
+    tx.vin[0].scriptSig = bytes([OP_TRUE]) + tx.vin[0].scriptSig[1:]
     tx.rehash()
 
 class NULLDUMMYTest(BitcoinTestFramework):
@@ -86,7 +85,7 @@ class NULLDUMMYTest(BitcoinTestFramework):
 
         self.log.info("Test 2: Non-NULLDUMMY base multisig transaction should not be accepted to mempool before activation")
         test2tx = create_transaction(self.nodes[0], txid2, self.ms_address, amount=47)
-        trueDummy(test2tx)
+        invalidate_nulldummy_tx(test2tx)
         assert_raises_rpc_error(-26, NULLDUMMY_ERROR, self.nodes[0].sendrawtransaction, test2tx.serialize().hex(), 0)
 
         self.log.info(f"Test 3: Non-NULLDUMMY base transactions should be accepted in a block before activation [{COINBASE_MATURITY + 4}]")
@@ -95,7 +94,7 @@ class NULLDUMMYTest(BitcoinTestFramework):
         self.log.info("Test 4: Non-NULLDUMMY base multisig transaction is invalid after activation")
         test4tx = create_transaction(self.nodes[0], test2tx.hash, self.address, amount=46)
         test6txs=[CTransaction(test4tx)]
-        trueDummy(test4tx)
+        invalidate_nulldummy_tx(test4tx)
         assert_raises_rpc_error(-26, NULLDUMMY_ERROR, self.nodes[0].sendrawtransaction, test4tx.serialize().hex(), 0)
         self.block_submit(self.nodes[0], [test4tx], accept=False)
 
@@ -110,12 +109,7 @@ class NULLDUMMYTest(BitcoinTestFramework):
         tmpl = node.getblocktemplate(NORMAL_GBT_REQUEST_PARAMS)
         assert_equal(tmpl['previousblockhash'], self.lastblockhash)
         assert_equal(tmpl['height'], self.lastblockheight + 1)
-        block = create_block(tmpl=tmpl, ntime=self.lastblocktime + 1, dip4_activated=dip4_activated)
-        for tx in txs:
-            tx.rehash()
-            block.vtx.append(tx)
-        block.hashMerkleRoot = block.calc_merkle_root()
-        block.rehash()
+        block = create_block(tmpl=tmpl, ntime=self.lastblocktime + 1, txlist=txs, dip4_activated=dip4_activated)
         block.solve()
         assert_equal(None if accept else NULLDUMMY_ERROR, node.submitblock(block.serialize().hex()))
         if accept: