Merge bitcoin/bitcoin#29496: policy: bump TX_MAX_STANDARD_VERSION to 3

30a01134cdec37e7467fcd6eee8b0ae3890a131c [doc] update bips.md for 431 (glozow)
9dbe6a03f0d6e70ccdf8e8715f888c0c17216bee [test] wallet uses CURRENT_VERSION which is 2 (glozow)
539404fe0fc0346b3aa77c330b38a5a0ad6565b2 [policy] make v3 transactions standard (glozow)
052ede75aff5c9f3a0a422ef413852eabeecc665 [refactor] use TRUC_VERSION in place of 3 (glozow)

Pull request description:

  Make `nVersion=3` (which is currently nonstandard on mainnet) standard.

  Note that we will treat these transactions as Topologically Restricted Until Confirmation (TRUC). Spec is in BIP 431 and implementation is in #28948, #29306, and #29873

  See #27463 for overall project tracking, and #29319 for information about relevance to cluster mempool.

ACKs for top commit:
  sdaftuar:
    utACK 30a01134c
  achow101:
    ACK 30a01134cdec37e7467fcd6eee8b0ae3890a131c
  instagibbs:
    utACK 30a01134cdec37e7467fcd6eee8b0ae3890a131c
  murchandamus:
    ACK 30a01134cdec37e7467fcd6eee8b0ae3890a131c
  ismaelsadeeq:
    ACK 30a01134cdec37e7467fcd6eee8b0ae3890a131c 🛰️

Tree-SHA512: 2a4aec0442c860e792a061d83e36483c1f1b426f946efbdf664c8db97a596e498b535707e1d3a900218429486ea69fd4552e3d476526a6883cbd5556c6534b48

12 files changed, 58 insertions, 35 deletions

diff --git a/doc/bips.md b/doc/bips.md
index 8309ee7e92..19a8091f55 100644
--- a/doc/bips.md
+++ b/doc/bips.md
@@ -69,3 +69,4 @@ BIPs that are implemented by Bitcoin Core:
   [`385`](https://github.com/bitcoin/bips/blob/master/bip-0385.mediawiki):
   Output Script Descriptors, and most of Script Expressions are implemented as of **v0.17.0** ([PR 13697](https://github.com/bitcoin/bitcoin/pull/13697)).
 * [`BIP 386`](https://github.com/bitcoin/bips/blob/master/bip-0386.mediawiki): tr() Output Script Descriptors are implemented as of **v22.0** ([PR 22051](https://github.com/bitcoin/bitcoin/pull/22051)).
+* [`BIP 431`](https://github.com/bitcoin/bips/blob/master/bip-0431.mediawiki): transactions with nVersion=3 are standard and treated as Topologically Restricted Until Confirmation as of **v28.0** ([PR 29496](https://github.com/bitcoin/bitcoin/pull/29496)).
diff --git a/src/policy/policy.h b/src/policy/policy.h
index 6a7980c312..20d632183a 100644
--- a/src/policy/policy.h
+++ b/src/policy/policy.h
@@ -131,7 +131,7 @@ bool IsStandard(const CScript& scriptPubKey, const std::optional<unsigned>& max_
 // Changing the default transaction version requires a two step process: first
 // adapting relay policy by bumping TX_MAX_STANDARD_VERSION, and then later
 // allowing the new transaction version in the wallet/RPC.
-static constexpr decltype(CTransaction::nVersion) TX_MAX_STANDARD_VERSION{2};
+static constexpr decltype(CTransaction::nVersion) TX_MAX_STANDARD_VERSION{3};
 
 /**
 * Check for standard transaction types
diff --git a/src/policy/v3_policy.cpp b/src/policy/v3_policy.cpp
index d44832fceb..9151d97ac2 100644
--- a/src/policy/v3_policy.cpp
+++ b/src/policy/v3_policy.cpp
@@ -66,7 +66,7 @@ std::optional<std::string> PackageV3Checks(const CTransactionRef& ptx, int64_t v
     const auto in_package_parents{FindInPackageParents(package, ptx)};
 
     // Now we have all ancestors, so we can start checking v3 rules.
-    if (ptx->nVersion == 3) {
+    if (ptx->nVersion == TRUC_VERSION) {
         // SingleV3Checks should have checked this already.
         if (!Assume(vsize <= V3_MAX_VSIZE)) {
             return strprintf("v3 tx %s (wtxid=%s) is too big: %u > %u virtual bytes",
@@ -107,7 +107,7 @@ std::optional<std::string> PackageV3Checks(const CTransactionRef& ptx, int64_t v
             }();
 
             // If there is a parent, it must have the right version.
-            if (parent_info.m_version != 3) {
+            if (parent_info.m_version != TRUC_VERSION) {
                 return strprintf("v3 tx %s (wtxid=%s) cannot spend from non-v3 tx %s (wtxid=%s)",
                                  ptx->GetHash().ToString(), ptx->GetWitnessHash().ToString(),
                                  parent_info.m_txid.ToString(), parent_info.m_wtxid.ToString());
@@ -146,14 +146,14 @@ std::optional<std::string> PackageV3Checks(const CTransactionRef& ptx, int64_t v
     } else {
         // Non-v3 transactions cannot have v3 parents.
         for (auto it : mempool_ancestors) {
-            if (it->GetTx().nVersion == 3) {
+            if (it->GetTx().nVersion == TRUC_VERSION) {
                 return strprintf("non-v3 tx %s (wtxid=%s) cannot spend from v3 tx %s (wtxid=%s)",
                                  ptx->GetHash().ToString(), ptx->GetWitnessHash().ToString(),
                                  it->GetSharedTx()->GetHash().ToString(), it->GetSharedTx()->GetWitnessHash().ToString());
             }
         }
         for (const auto& index: in_package_parents) {
-            if (package.at(index)->nVersion == 3) {
+            if (package.at(index)->nVersion == TRUC_VERSION) {
                 return strprintf("non-v3 tx %s (wtxid=%s) cannot spend from v3 tx %s (wtxid=%s)",
                                  ptx->GetHash().ToString(),
                                  ptx->GetWitnessHash().ToString(),
@@ -172,12 +172,12 @@ std::optional<std::pair<std::string, CTransactionRef>> SingleV3Checks(const CTra
 {
     // Check v3 and non-v3 inheritance.
     for (const auto& entry : mempool_ancestors) {
-        if (ptx->nVersion != 3 && entry->GetTx().nVersion == 3) {
+        if (ptx->nVersion != TRUC_VERSION && entry->GetTx().nVersion == TRUC_VERSION) {
             return std::make_pair(strprintf("non-v3 tx %s (wtxid=%s) cannot spend from v3 tx %s (wtxid=%s)",
                              ptx->GetHash().ToString(), ptx->GetWitnessHash().ToString(),
                              entry->GetSharedTx()->GetHash().ToString(), entry->GetSharedTx()->GetWitnessHash().ToString()),
                 nullptr);
-        } else if (ptx->nVersion == 3 && entry->GetTx().nVersion != 3) {
+        } else if (ptx->nVersion == TRUC_VERSION && entry->GetTx().nVersion != TRUC_VERSION) {
             return std::make_pair(strprintf("v3 tx %s (wtxid=%s) cannot spend from non-v3 tx %s (wtxid=%s)",
                              ptx->GetHash().ToString(), ptx->GetWitnessHash().ToString(),
                              entry->GetSharedTx()->GetHash().ToString(), entry->GetSharedTx()->GetWitnessHash().ToString()),
@@ -190,7 +190,7 @@ std::optional<std::pair<std::string, CTransactionRef>> SingleV3Checks(const CTra
     static_assert(V3_DESCENDANT_LIMIT == 2);
 
     // The rest of the rules only apply to transactions with nVersion=3.
-    if (ptx->nVersion != 3) return std::nullopt;
+    if (ptx->nVersion != TRUC_VERSION) return std::nullopt;
 
     if (vsize > V3_MAX_VSIZE) {
         return std::make_pair(strprintf("v3 tx %s (wtxid=%s) is too big: %u > %u virtual bytes",
diff --git a/src/policy/v3_policy.h b/src/policy/v3_policy.h
index 25aff37a1b..84dadd8719 100644
--- a/src/policy/v3_policy.h
+++ b/src/policy/v3_policy.h
@@ -15,8 +15,9 @@
 #include <set>
 #include <string>
 
-// This module enforces rules for transactions with nVersion=3 ("v3 transactions") which help make
+// This module enforces rules for BIP 431 TRUC transactions (with nVersion=3) which help make
 // RBF abilities more robust.
+static constexpr decltype(CTransaction::nVersion) TRUC_VERSION{3};
 
 // v3 only allows 1 parent and 1 child when unconfirmed.
 /** Maximum number of transactions including an unconfirmed tx and its descendants. */
diff --git a/src/test/fuzz/package_eval.cpp b/src/test/fuzz/package_eval.cpp
index c201118bce..c13f229463 100644
--- a/src/test/fuzz/package_eval.cpp
+++ b/src/test/fuzz/package_eval.cpp
@@ -173,7 +173,7 @@ FUZZ_TARGET(tx_package_eval, .init = initialize_tx_pool)
             // Create transaction to add to the mempool
             const CTransactionRef tx = [&] {
                 CMutableTransaction tx_mut;
-                tx_mut.nVersion = fuzzed_data_provider.ConsumeBool() ? 3 : CTransaction::CURRENT_VERSION;
+                tx_mut.nVersion = fuzzed_data_provider.ConsumeBool() ? TRUC_VERSION : CTransaction::CURRENT_VERSION;
                 tx_mut.nLockTime = fuzzed_data_provider.ConsumeBool() ? 0 : fuzzed_data_provider.ConsumeIntegral<uint32_t>();
                 // Last tx will sweep all outpoints in package
                 const auto num_in = last_tx ? package_outpoints.size()  : fuzzed_data_provider.ConsumeIntegralInRange<int>(1, mempool_outpoints.size());
diff --git a/src/test/fuzz/tx_pool.cpp b/src/test/fuzz/tx_pool.cpp
index 9f0aedf29b..87c1e5a97c 100644
--- a/src/test/fuzz/tx_pool.cpp
+++ b/src/test/fuzz/tx_pool.cpp
@@ -226,7 +226,7 @@ FUZZ_TARGET(tx_pool_standard, .init = initialize_tx_pool)
         // Create transaction to add to the mempool
         const CTransactionRef tx = [&] {
             CMutableTransaction tx_mut;
-            tx_mut.nVersion = fuzzed_data_provider.ConsumeBool() ? 3 : CTransaction::CURRENT_VERSION;
+            tx_mut.nVersion = fuzzed_data_provider.ConsumeBool() ? TRUC_VERSION : CTransaction::CURRENT_VERSION;
             tx_mut.nLockTime = fuzzed_data_provider.ConsumeBool() ? 0 : fuzzed_data_provider.ConsumeIntegral<uint32_t>();
             const auto num_in = fuzzed_data_provider.ConsumeIntegralInRange<int>(1, outpoints_rbf.size());
             const auto num_out = fuzzed_data_provider.ConsumeIntegralInRange<int>(1, outpoints_rbf.size() * 2);
diff --git a/src/test/txvalidation_tests.cpp b/src/test/txvalidation_tests.cpp
index 95583b53bf..f36c245383 100644
--- a/src/test/txvalidation_tests.cpp
+++ b/src/test/txvalidation_tests.cpp
@@ -286,7 +286,7 @@ BOOST_FIXTURE_TEST_CASE(version3_tests, RegTestingSetup)
     script_multisig << OP_2 << OP_CHECKMULTISIG;
     {
         CMutableTransaction mtx_many_sigops = CMutableTransaction{};
-        mtx_many_sigops.nVersion = 3;
+        mtx_many_sigops.nVersion = TRUC_VERSION;
         for (const auto& outpoint : multisig_outpoints) {
             mtx_many_sigops.vin.emplace_back(outpoint);
             mtx_many_sigops.vin.back().scriptWitness.stack.emplace_back(script_multisig.begin(), script_multisig.end());
diff --git a/src/test/util/txmempool.cpp b/src/test/util/txmempool.cpp
index 2657104e7d..4dfc09ef67 100644
--- a/src/test/util/txmempool.cpp
+++ b/src/test/util/txmempool.cpp
@@ -118,7 +118,7 @@ void CheckMempoolV3Invariants(const CTxMemPool& tx_pool)
     LOCK(tx_pool.cs);
     for (const auto& tx_info : tx_pool.infoAll()) {
         const auto& entry = *Assert(tx_pool.GetEntry(tx_info.tx->GetHash()));
-        if (tx_info.tx->nVersion == 3) {
+        if (tx_info.tx->nVersion == TRUC_VERSION) {
             // Check that special maximum virtual size is respected
             Assert(entry.GetTxSize() <= V3_MAX_VSIZE);
 
@@ -133,12 +133,12 @@ void CheckMempoolV3Invariants(const CTxMemPool& tx_pool)
                 Assert(entry.GetTxSize() <= V3_CHILD_MAX_VSIZE);
                 // All v3 transactions must only have v3 unconfirmed parents.
                 const auto& parents = entry.GetMemPoolParentsConst();
-                Assert(parents.begin()->get().GetSharedTx()->nVersion == 3);
+                Assert(parents.begin()->get().GetSharedTx()->nVersion == TRUC_VERSION);
             }
         } else if (entry.GetCountWithAncestors() > 1) {
             // All non-v3 transactions must only have non-v3 unconfirmed parents.
             for (const auto& parent : entry.GetMemPoolParentsConst()) {
-                Assert(parent.get().GetSharedTx()->nVersion != 3);
+                Assert(parent.get().GetSharedTx()->nVersion != TRUC_VERSION);
             }
         }
     }
diff --git a/src/validation.cpp b/src/validation.cpp
index 4e6f0ed702..cecee0e9a9 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -831,7 +831,7 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
                 //
                 // Replaceability signaling of the original transactions may be
                 // ignored due to node setting.
-                const bool allow_rbf{m_pool.m_opts.full_rbf || SignalsOptInRBF(*ptxConflicting) || ptxConflicting->nVersion == 3};
+                const bool allow_rbf{m_pool.m_opts.full_rbf || SignalsOptInRBF(*ptxConflicting) || ptxConflicting->nVersion == TRUC_VERSION};
                 if (!allow_rbf) {
                     return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "txn-mempool-conflict");
                 }
@@ -935,7 +935,7 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
     // method of ensuring the tx remains bumped. For example, the fee-bumping child could disappear
     // due to a replacement.
     // The only exception is v3 transactions.
-    if (!bypass_limits && ws.m_ptx->nVersion != 3 && ws.m_modified_fees < m_pool.m_opts.min_relay_feerate.GetFee(ws.m_vsize)) {
+    if (!bypass_limits && ws.m_ptx->nVersion != TRUC_VERSION && ws.m_modified_fees < m_pool.m_opts.min_relay_feerate.GetFee(ws.m_vsize)) {
         // Even though this is a fee-related failure, this result is TX_MEMPOOL_POLICY, not
         // TX_RECONSIDERABLE, because it cannot be bypassed using package validation.
         return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "min relay fee not met",
@@ -1017,7 +1017,7 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
             .descendant_count = maybe_rbf_limits.descendant_count + 1,
             .descendant_size_vbytes = maybe_rbf_limits.descendant_size_vbytes + EXTRA_DESCENDANT_TX_SIZE_LIMIT,
         };
-        if (ws.m_vsize > EXTRA_DESCENDANT_TX_SIZE_LIMIT || ws.m_ptx->nVersion == 3) {
+        if (ws.m_vsize > EXTRA_DESCENDANT_TX_SIZE_LIMIT || ws.m_ptx->nVersion == TRUC_VERSION) {
             return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "too-long-mempool-chain", error_message);
         }
         if (auto ancestors_retry{m_pool.CalculateMemPoolAncestors(*entry, cpfp_carve_out_limits)}) {
diff --git a/test/functional/mempool_accept.py b/test/functional/mempool_accept.py
index b00be5f4f0..2de4cf1e10 100755
--- a/test/functional/mempool_accept.py
+++ b/test/functional/mempool_accept.py
@@ -287,7 +287,7 @@ class MempoolAcceptanceTest(BitcoinTestFramework):
 
         self.log.info('Some nonstandard transactions')
         tx = tx_from_hex(raw_tx_reference)
-        tx.nVersion = 3  # A version currently non-standard
+        tx.nVersion = 4  # A version currently non-standard
         self.check_mempool_result(
             result_expected=[{'txid': tx.rehash(), 'allowed': False, 'reject-reason': 'version'}],
             rawtxs=[tx.serialize().hex()],
diff --git a/test/functional/mempool_accept_v3.py b/test/functional/mempool_accept_v3.py
index 6b0ba0812b..d4a33c232e 100755
--- a/test/functional/mempool_accept_v3.py
+++ b/test/functional/mempool_accept_v3.py
@@ -42,7 +42,7 @@ def cleanup(extra_args=None):
 class MempoolAcceptV3(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 1
-        self.extra_args = [["-acceptnonstdtxn=1"]]
+        self.extra_args = [[]]
         self.setup_clean_chain = True
 
     def check_mempool(self, txids):
@@ -51,7 +51,7 @@ class MempoolAcceptV3(BitcoinTestFramework):
         assert_equal(len(txids), len(mempool_contents))
         assert all([txid in txids for txid in mempool_contents])
 
-    @cleanup(extra_args=["-datacarriersize=20000", "-acceptnonstdtxn=1"])
+    @cleanup(extra_args=["-datacarriersize=20000"])
     def test_v3_max_vsize(self):
         node = self.nodes[0]
         self.log.info("Test v3-specific maximum transaction vsize")
@@ -65,7 +65,7 @@ class MempoolAcceptV3(BitcoinTestFramework):
         tx_v2_heavy = self.wallet.send_self_transfer(from_node=node, target_weight=(V3_MAX_VSIZE + 1) * WITNESS_SCALE_FACTOR, version=2)
         self.check_mempool([tx_v2_heavy["txid"]])
 
-    @cleanup(extra_args=["-datacarriersize=1000", "-acceptnonstdtxn=1"])
+    @cleanup(extra_args=["-datacarriersize=1000"])
     def test_v3_acceptance(self):
         node = self.nodes[0]
         self.log.info("Test a child of a v3 transaction cannot be more than 1000vB")
@@ -105,7 +105,7 @@ class MempoolAcceptV3(BitcoinTestFramework):
         self.check_mempool([tx_v3_parent_normal["txid"], tx_v3_child_almost_heavy_rbf["txid"]])
         assert_equal(node.getmempoolentry(tx_v3_parent_normal["txid"])["descendantcount"], 2)
 
-    @cleanup(extra_args=["-acceptnonstdtxn=1"])
+    @cleanup(extra_args=None)
     def test_v3_replacement(self):
         node = self.nodes[0]
         self.log.info("Test v3 transactions may be replaced by v3 transactions")
@@ -162,7 +162,7 @@ class MempoolAcceptV3(BitcoinTestFramework):
         self.check_mempool([tx_v3_bip125_rbf_v2["txid"], tx_v3_parent["txid"], tx_v3_child["txid"]])
 
 
-    @cleanup(extra_args=["-acceptnonstdtxn=1"])
+    @cleanup(extra_args=None)
     def test_v3_bip125(self):
         node = self.nodes[0]
         self.log.info("Test v3 transactions that don't signal BIP125 are replaceable")
@@ -186,7 +186,7 @@ class MempoolAcceptV3(BitcoinTestFramework):
         )
         self.check_mempool([tx_v3_no_bip125_rbf["txid"]])
 
-    @cleanup(extra_args=["-datacarriersize=40000", "-acceptnonstdtxn=1"])
+    @cleanup(extra_args=["-datacarriersize=40000"])
     def test_v3_reorg(self):
         node = self.nodes[0]
         self.log.info("Test that, during a reorg, v3 rules are not enforced")
@@ -208,7 +208,7 @@ class MempoolAcceptV3(BitcoinTestFramework):
         node.reconsiderblock(block[0])
 
 
-    @cleanup(extra_args=["-limitdescendantsize=10", "-datacarriersize=40000", "-acceptnonstdtxn=1"])
+    @cleanup(extra_args=["-limitdescendantsize=10", "-datacarriersize=40000"])
     def test_nondefault_package_limits(self):
         """
         Max standard tx size + v3 rules imply the ancestor/descendant rules (at their default
@@ -241,7 +241,7 @@ class MempoolAcceptV3(BitcoinTestFramework):
         self.generate(node, 1)
 
         self.log.info("Test that a decreased limitancestorsize also applies to v3 parent")
-        self.restart_node(0, extra_args=["-limitancestorsize=10", "-datacarriersize=40000", "-acceptnonstdtxn=1"])
+        self.restart_node(0, extra_args=["-limitancestorsize=10", "-datacarriersize=40000"])
         tx_v3_parent_large2 = self.wallet.send_self_transfer(
             from_node=node,
             target_weight=parent_target_weight,
@@ -261,7 +261,7 @@ class MempoolAcceptV3(BitcoinTestFramework):
         assert_raises_rpc_error(-26, f"too-long-mempool-chain, exceeds ancestor size limit", node.sendrawtransaction, tx_v3_child_large2["hex"])
         self.check_mempool([tx_v3_parent_large2["txid"]])
 
-    @cleanup(extra_args=["-datacarriersize=1000", "-acceptnonstdtxn=1"])
+    @cleanup(extra_args=["-datacarriersize=1000"])
     def test_v3_ancestors_package(self):
         self.log.info("Test that v3 ancestor limits are checked within the package")
         node = self.nodes[0]
@@ -304,7 +304,7 @@ class MempoolAcceptV3(BitcoinTestFramework):
         result = node.testmempoolaccept([tx_v3_parent["hex"], tx_v3_child["hex"], tx_v3_grandchild["hex"]])
         assert all([txresult["package-error"] == f"v3-violation, tx {tx_v3_grandchild['txid']} (wtxid={tx_v3_grandchild['wtxid']}) would have too many ancestors" for txresult in result])
 
-    @cleanup(extra_args=["-acceptnonstdtxn=1"])
+    @cleanup(extra_args=None)
     def test_v3_ancestors_package_and_mempool(self):
         """
         A v3 transaction in a package cannot have 2 v3 parents.
@@ -334,7 +334,7 @@ class MempoolAcceptV3(BitcoinTestFramework):
         assert_equal(result['package_msg'], f"v3-violation, tx {tx_child_violator['txid']} (wtxid={tx_child_violator['wtxid']}) would have too many ancestors")
         self.check_mempool([tx_in_mempool["txid"]])
 
-    @cleanup(extra_args=["-acceptnonstdtxn=1"])
+    @cleanup(extra_args=None)
     def test_sibling_eviction_package(self):
         """
         When a transaction has a mempool sibling, it may be eligible for sibling eviction.
@@ -410,7 +410,7 @@ class MempoolAcceptV3(BitcoinTestFramework):
         assert_equal(result_package_cpfp["tx-results"][tx_sibling_3['wtxid']]['error'], expected_error_cpfp)
 
 
-    @cleanup(extra_args=["-datacarriersize=1000", "-acceptnonstdtxn=1"])
+    @cleanup(extra_args=["-datacarriersize=1000"])
     def test_v3_package_inheritance(self):
         self.log.info("Test that v3 inheritance is checked within package")
         node = self.nodes[0]
@@ -429,7 +429,7 @@ class MempoolAcceptV3(BitcoinTestFramework):
         assert_equal(result['package_msg'], f"v3-violation, non-v3 tx {tx_v2_child['txid']} (wtxid={tx_v2_child['wtxid']}) cannot spend from v3 tx {tx_v3_parent['txid']} (wtxid={tx_v3_parent['wtxid']})")
         self.check_mempool([])
 
-    @cleanup(extra_args=["-acceptnonstdtxn=1"])
+    @cleanup(extra_args=None)
     def test_v3_in_testmempoolaccept(self):
         node = self.nodes[0]
 
@@ -479,7 +479,7 @@ class MempoolAcceptV3(BitcoinTestFramework):
         test_accept_2children_with_in_mempool_parent = node.testmempoolaccept([tx_v3_child_1["hex"], tx_v3_child_2["hex"]])
         assert all([result["package-error"] == expected_error_extra for result in test_accept_2children_with_in_mempool_parent])
 
-    @cleanup(extra_args=["-acceptnonstdtxn=1"])
+    @cleanup(extra_args=None)
     def test_reorg_2child_rbf(self):
         node = self.nodes[0]
         self.log.info("Test that children of a v3 transaction can be replaced individually, even if there are multiple due to reorg")
@@ -510,7 +510,7 @@ class MempoolAcceptV3(BitcoinTestFramework):
         self.check_mempool([ancestor_tx["txid"], child_1_conflict["txid"], child_2["txid"]])
         assert_equal(node.getmempoolentry(ancestor_tx["txid"])["descendantcount"], 3)
 
-    @cleanup(extra_args=["-acceptnonstdtxn=1"])
+    @cleanup(extra_args=None)
     def test_v3_sibling_eviction(self):
         self.log.info("Test sibling eviction for v3")
         node = self.nodes[0]
@@ -583,7 +583,7 @@ class MempoolAcceptV3(BitcoinTestFramework):
         node.sendrawtransaction(tx_v3_child_3["hex"])
         self.check_mempool(txids_v2_100 + [tx_v3_parent["txid"], tx_v3_child_3["txid"]])
 
-    @cleanup(extra_args=["-acceptnonstdtxn=1"])
+    @cleanup(extra_args=None)
     def test_reorg_sibling_eviction_1p2c(self):
         node = self.nodes[0]
         self.log.info("Test that sibling eviction is not allowed when multiple siblings exist")
diff --git a/test/functional/wallet_create_tx.py b/test/functional/wallet_create_tx.py
index 4e31b48ec0..fb1ee3ae61 100755
--- a/test/functional/wallet_create_tx.py
+++ b/test/functional/wallet_create_tx.py
@@ -3,6 +3,9 @@
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+from test_framework.messages import (
+    tx_from_hex,
+)
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_equal,
@@ -33,6 +36,7 @@ class CreateTxWalletTest(BitcoinTestFramework):
         self.test_anti_fee_sniping()
         self.test_tx_size_too_large()
         self.test_create_too_long_mempool_chain()
+        self.test_version3()
 
     def test_anti_fee_sniping(self):
         self.log.info('Check that we have some (old) blocks and that anti-fee-sniping is disabled')
@@ -106,6 +110,23 @@ class CreateTxWalletTest(BitcoinTestFramework):
 
         test_wallet.unloadwallet()
 
+    def test_version3(self):
+        self.log.info('Check wallet does not create transactions with nVersion=3 yet')
+        wallet_rpc = self.nodes[0].get_wallet_rpc(self.default_wallet_name)
+
+        self.nodes[0].createwallet("v3")
+        wallet_v3 = self.nodes[0].get_wallet_rpc("v3")
+
+        tx_data = wallet_rpc.send(outputs=[{wallet_v3.getnewaddress(): 25}], options={"change_position": 0})
+        wallet_tx_data = wallet_rpc.gettransaction(tx_data["txid"])
+        tx_current_version = tx_from_hex(wallet_tx_data["hex"])
+
+        # While v3 transactions are standard, the CURRENT_VERSION is 2.
+        # This test can be removed if CURRENT_VERSION is changed, and replaced with tests that the
+        # wallet handles v3 rules properly.
+        assert_equal(tx_current_version.nVersion, 2)
+        wallet_v3.unloadwallet()
+
 
 if __name__ == '__main__':
     CreateTxWalletTest().main()