1 files changed, 25 insertions, 18 deletions
diff --git a/src/policy/policy.h b/src/policy/policy.h
index 726a14a27e..f2a3f35546 100644
--- a/src/policy/policy.h
+++ b/src/policy/policy.h
@@ -1,5 +1,5 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2019 The Bitcoin Core developers
+// Copyright (c) 2009-2020 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -90,25 +90,32 @@ CAmount GetDustThreshold(const CTxOut& txout, const CFeeRate& dustRelayFee);
 bool IsDust(const CTxOut& txout, const CFeeRate& dustRelayFee);
 
 bool IsStandard(const CScript& scriptPubKey, TxoutType& whichType);
-    /**
-     * Check for standard transaction types
-     * @return True if all outputs (scriptPubKeys) use only standard transaction forms
-     */
+
+
+// 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};
+
+/**
+* Check for standard transaction types
+* @return True if all outputs (scriptPubKeys) use only standard transaction forms
+*/
 bool IsStandardTx(const CTransaction& tx, bool permit_bare_multisig, const CFeeRate& dust_relay_fee, std::string& reason);
-    /**
-     * Check for standard transaction types
-     * @param[in] mapInputs       Map of previous transactions that have outputs we're spending
-     * @param[in] taproot_active  Whether or taproot consensus rules are active (used to decide whether spends of them are permitted)
-     * @return True if all inputs (scriptSigs) use only standard transaction forms
-     */
+/**
+* Check for standard transaction types
+* @param[in] mapInputs       Map of previous transactions that have outputs we're spending
+* @param[in] taproot_active  Whether or taproot consensus rules are active (used to decide whether spends of them are permitted)
+* @return True if all inputs (scriptSigs) use only standard transaction forms
+*/
 bool AreInputsStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs, bool taproot_active);
-    /**
-     * Check if the transaction is over standard P2WSH resources limit:
-     * 3600bytes witnessScript size, 80bytes per witness stack element, 100 witness stack elements
-     * These limits are adequate for multisignatures up to n-of-100 using OP_CHECKSIG, OP_ADD, and OP_EQUAL.
-     *
-     * Also enforce a maximum stack item size limit and no annexes for tapscript spends.
-     */
+/**
+* Check if the transaction is over standard P2WSH resources limit:
+* 3600bytes witnessScript size, 80bytes per witness stack element, 100 witness stack elements
+* These limits are adequate for multisignatures up to n-of-100 using OP_CHECKSIG, OP_ADD, and OP_EQUAL.
+*
+* Also enforce a maximum stack item size limit and no annexes for tapscript spends.
+*/
 bool IsWitnessStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs);
 
 /** Compute the virtual transaction size (weight reinterpreted as bytes). */