Enable seamless spending of timelocked coinbases through z_shieldcoinbase

src/miner.cpp

@@ -784,7 +784,7 @@ void static BitcoinMiner_noeq()
     do {
         curTip = chainActive.Tip();
         printf("Verifying block height %d         \n", chainActive.Tip()->nHeight);
-        MilliSleep(100 + rand() % 1900);
+        MilliSleep(1000 + rand() % 1900);
     } while (curTip != chainActive.Tip());
 
     SetThreadPriority(THREAD_PRIORITY_LOWEST);

src/script/sign.cpp

@@ -75,8 +75,25 @@ static bool SignStep(const BaseSignatureCreator& creator, const CScript& scriptP
     ret.clear();
 
     vector<valtype> vSolutions;
+
     if (!Solver(scriptPubKey, whichTypeRet, vSolutions))
-        return false;
+    {
+        // if this is a CLTV script, solve for the destination after CLTV
+        if (scriptPubKey.IsCheckLockTimeVerify())
+        {
+            uint8_t pushOp = scriptPubKey.data()[0];
+            uint32_t scriptStart = pushOp + 3;
+
+            // check post CLTV script
+            CScript postfix = CScript(scriptPubKey.size() > scriptStart ? scriptPubKey.begin() + scriptStart : scriptPubKey.end(), scriptPubKey.end());
+
+            // check again with only postfix subscript
+            if (!Solver(postfix, whichTypeRet, vSolutions))
+                return false;
+        }
+        else
+            return false;
+    }
 
     CKeyID keyID;
     switch (whichTypeRet)

src/wallet/asyncrpcoperation_shieldcoinbase.cpp

@@ -211,6 +211,7 @@ bool AsyncRPCOperation_shieldcoinbase::main_impl() {
     CMutableTransaction rawTx(tx_);
     for (ShieldCoinbaseUTXO & t : inputs_) {
         CTxIn in(COutPoint(t.txid, t.vout));
+        in.nSequence = 0;
         rawTx.vin.push_back(in);
     }
     tx_ = CTransaction(rawTx);

src/wallet/rpcwallet.cpp

@@ -3971,6 +3971,7 @@ UniValue z_shieldcoinbase(const UniValue& params, bool fHelp)
         if (!ExtractDestination(out.tx->vout[out.i].scriptPubKey, address)) {
             continue;
         }
+
         // If taddr is not wildcard "*", filter utxos
         if (setAddress.size()>0 && !setAddress.count(address)) {
             continue;
@@ -4035,6 +4036,7 @@ UniValue z_shieldcoinbase(const UniValue& params, bool fHelp)
     int nextBlockHeight = chainActive.Height() + 1;
     CMutableTransaction contextualTx = CreateNewContextualCMutableTransaction(
         Params().GetConsensus(), nextBlockHeight);
+    contextualTx.nLockTime = nextBlockHeight;
     if (contextualTx.nVersion == 1) {
         contextualTx.nVersion = 2; // Tx format should support vjoinsplits
     }

src/wallet/wallet.cpp

@@ -3916,9 +3916,10 @@ int CMerkleTx::GetBlocksToMaturity() const
     if (!IsCoinBase())
         return 0;
     int32_t depth = GetDepthInMainChain();
-    int32_t ui;
-    int32_t toMaturity = (ui = UnlockTime(0) - chainActive.Height()) < 0 ? 0 : ui;
-    return((ui = COINBASE_MATURITY - depth) < toMaturity ? toMaturity : ui);
+    int32_t ut = UnlockTime(0);
+    int32_t toMaturity = ut - chainActive.Height() < 0 ? 0 : ut - chainActive.Height();
+    ut = COINBASE_MATURITY - depth < 0 ? 0 : COINBASE_MATURITY - depth;
+    return(ut < toMaturity ? toMaturity : ut);
 }
 
 bool CMerkleTx::AcceptToMemoryPool(bool fLimitFree, bool fRejectAbsurdFee)