Allow to opt-into RBF when creating a transaction

Author: jonasschnelli

src/wallet/coincontrol.h

@@ -6,6 +6,7 @@
 #define BITCOIN_WALLET_COINCONTROL_H
 
 #include "primitives/transaction.h"
+#include "wallet/wallet.h"
 
 /** Coin Control Features. */
 class CCoinControl
@@ -24,6 +25,8 @@ class CCoinControl
     CFeeRate nFeeRate;
     //! Override the default confirmation target, 0 = use default
     int nConfirmTarget;
+    //! Signal BIP-125 replace by fee.
+    bool signalRbf;
 
     CCoinControl()
     {
@@ -40,6 +43,7 @@ class CCoinControl
         nFeeRate = CFeeRate(0);
         fOverrideFeeRate = false;
         nConfirmTarget = 0;
+        signalRbf = fWalletRbf;
     }
 
     bool HasSelected() const

src/wallet/wallet.cpp

@@ -2566,9 +2566,10 @@ bool CWallet::CreateTransaction(const vector<CRecipient>& vecSend, CWalletTx& wt
                 // to avoid conflicting with other possible uses of nSequence,
                 // and in the spirit of "smallest posible change from prior
                 // behavior."
+                bool rbf = coinControl ? coinControl->signalRbf : fWalletRbf;
                 for (const auto& coin : setCoins)
                     txNew.vin.push_back(CTxIn(coin.first->GetHash(),coin.second,CScript(),
-                                              std::numeric_limits<unsigned int>::max() - (fWalletRbf ? 2 : 1)));
+                                              std::numeric_limits<unsigned int>::max() - (rbf ? 2 : 1)));
 
                 // Fill in dummy signatures for fee calculation.
                 int nIn = 0;