Make witness v0 outputs non-standard before segwit activation

Github-Pull: #8381
Rebased-From: 1ffaff2f74

src/main.cpp

@@ -1144,13 +1144,14 @@ bool AcceptToMemoryPoolWorker(CTxMemPool& pool, CValidationState& state, const C
     }
 
     // Reject transactions with witness before segregated witness activates (override with -prematurewitness)
-    if (!GetBoolArg("-prematurewitness",false) && !tx.wit.IsNull() && !IsWitnessEnabled(chainActive.Tip(), Params().GetConsensus())) {
+    bool witnessEnabled = IsWitnessEnabled(chainActive.Tip(), Params().GetConsensus());
+    if (!GetBoolArg("-prematurewitness",false) && !tx.wit.IsNull() && !witnessEnabled) {
         return state.DoS(0, false, REJECT_NONSTANDARD, "no-witness-yet", true);
     }
 
     // Rather not work on nonstandard transactions (unless -testnet/-regtest)
     string reason;
-    if (fRequireStandard && !IsStandardTx(tx, reason))
+    if (fRequireStandard && !IsStandardTx(tx, reason, witnessEnabled))
         return state.DoS(0, false, REJECT_NONSTANDARD, reason);
 
     // Only accept nLockTime-using transactions that can be mined in the next

src/policy/policy.cpp

@@ -31,7 +31,7 @@
      *   DUP CHECKSIG DROP ... repeated 100 times... OP_1
      */
 
-bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType)
+bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType, const bool witnessEnabled)
 {
     std::vector<std::vector<unsigned char> > vSolutions;
     if (!Solver(scriptPubKey, whichType, vSolutions))
@@ -50,10 +50,13 @@ bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType)
                (!fAcceptDatacarrier || scriptPubKey.size() > nMaxDatacarrierBytes))
           return false;
           
+    else if (!witnessEnabled && (whichType == TX_WITNESS_V0_KEYHASH || whichType == TX_WITNESS_V0_SCRIPTHASH))
+        return false;
+
     return whichType != TX_NONSTANDARD;
 }
 
-bool IsStandardTx(const CTransaction& tx, std::string& reason)
+bool IsStandardTx(const CTransaction& tx, std::string& reason, const bool witnessEnabled)
 {
     if (tx.nVersion > CTransaction::MAX_STANDARD_VERSION || tx.nVersion < 1) {
         reason = "version";
@@ -92,7 +95,7 @@ bool IsStandardTx(const CTransaction& tx, std::string& reason)
     unsigned int nDataOut = 0;
     txnouttype whichType;
     BOOST_FOREACH(const CTxOut& txout, tx.vout) {
-        if (!::IsStandard(txout.scriptPubKey, whichType)) {
+        if (!::IsStandard(txout.scriptPubKey, whichType, witnessEnabled)) {
             reason = "scriptpubkey";
             return false;
         }

src/policy/policy.h

@@ -53,12 +53,12 @@ static const unsigned int STANDARD_NOT_MANDATORY_VERIFY_FLAGS = STANDARD_SCRIPT_
 static const unsigned int STANDARD_LOCKTIME_VERIFY_FLAGS = LOCKTIME_VERIFY_SEQUENCE |
                                                            LOCKTIME_MEDIAN_TIME_PAST;
 
-bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType);
+bool IsStandard(const CScript& scriptPubKey, txnouttype& whichType, const bool witnessEnabled = false);
     /**
      * Check for standard transaction types
      * @return True if all outputs (scriptPubKeys) use only standard transaction forms
      */
-bool IsStandardTx(const CTransaction& tx, std::string& reason);
+bool IsStandardTx(const CTransaction& tx, std::string& reason, const bool witnessEnabled = false);
     /**
      * Check for standard transaction types
      * @param[in] mapInputs    Map of previous transactions that have outputs we're spending