validation: Check only MANDATORY_SCRIPT_VERIFY_FLAGS when -acceptnons…

…tdtxn is set

src/validation.cpp

@@ -1010,8 +1010,7 @@ bool MemPoolAccept::PolicyScriptChecks(const ATMPArgs& args, Workspace& ws)
     AssertLockHeld(m_pool.cs);
     const CTransaction& tx = *ws.m_ptx;
     TxValidationState& state = ws.m_state;
-
-    constexpr unsigned int scriptVerifyFlags = STANDARD_SCRIPT_VERIFY_FLAGS;
+    const unsigned int scriptVerifyFlags = (m_pool.m_require_standard ? STANDARD_SCRIPT_VERIFY_FLAGS : MANDATORY_SCRIPT_VERIFY_FLAGS);
 
     // Check input scripts and signatures.
     // This is done last to help prevent CPU exhaustion denial-of-service attacks.
@@ -2009,6 +2008,10 @@ static unsigned int GetBlockScriptFlags(const CBlockIndex& block_index, const Ch
 {
     const Consensus::Params& consensusparams = chainman.GetConsensus();
 
+    // Note that any flags returned from this function (ie, specified
+    // here or in script_flag_exceptions) must also be included in
+    // MANDATORY_SCRIPT_VERIFY_FLAGS in policy/policy.h
+
     // BIP16 didn't become active until Apr 1 2012 (on mainnet, and
     // retroactively applied to testnet)
     // However, only one historical block violated the P2SH rules (on both

test/functional/p2p_segwit.py

@@ -1393,9 +1393,8 @@ def test_segwit_versions(self):
         # Now the node will no longer ask for getdata of this transaction when advertised by same txid
         self.std_node.announce_tx_and_wait_for_getdata(tx3, success=False)
 
-        # Spending a higher version witness output is not allowed by policy,
-        # even with the node that accepts non-standard txs.
-        test_transaction_acceptance(self.nodes[0], self.test_node, tx3, with_witness=True, accepted=False, reason="reserved for soft-fork upgrades")
+        # Spending a higher version witness output is allowed on the node with -acceptnonstdtxn
+        test_transaction_acceptance(self.nodes[0], self.test_node, tx3, with_witness=True, accepted=True)
 
         # Building a block with the transaction must be valid, however even without -acceptnonstdtxn.
         block = self.build_next_block()