1 files changed, 56 insertions, 54 deletions

diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 6cf4c53da5..13da7bb2c2 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2469,9 +2469,9 @@ bool CWallet::FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, int& nC
 
     CReserveKey reservekey(this);
     CWalletTx wtx;
-    if (!CreateTransaction(vecSend, wtx, reservekey, nFeeRet, nChangePosInOut, strFailReason, &coinControl, false))
+    if (!CreateTransaction(vecSend, wtx, reservekey, nFeeRet, nChangePosInOut, strFailReason, coinControl, false)) {
         return false;
-
+    }
     if (nChangePosInOut != -1)
         tx.vout.insert(tx.vout.begin() + nChangePosInOut, wtx.tx->vout[nChangePosInOut]);
 
@@ -2502,7 +2502,7 @@ bool CWallet::FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, int& nC
 }
 
 bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletTx& wtxNew, CReserveKey& reservekey, CAmount& nFeeRet,
-                                int& nChangePosInOut, std::string& strFailReason, const CCoinControl* coinControl, bool sign)
+                                int& nChangePosInOut, std::string& strFailReason, const CCoinControl& coin_control, bool sign)
 {
     CAmount nValue = 0;
     int nChangePosRequest = nChangePosInOut;
@@ -2567,7 +2567,7 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletT
         LOCK2(cs_main, cs_wallet);
         {
             std::vector<COutput> vAvailableCoins;
-            AvailableCoins(vAvailableCoins, true, coinControl);
+            AvailableCoins(vAvailableCoins, true, &coin_control);
 
             // Create change script that will be used if we need change
             // TODO: pass in scriptChange instead of reservekey so
@@ -2575,12 +2575,9 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletT
             CScript scriptChange;
 
             // coin control: send change to custom address
-            if (coinControl && !boost::get<CNoDestination>(&coinControl->destChange))
-                scriptChange = GetScriptForDestination(coinControl->destChange);
-
-            // no coin control: send change to newly generated address
-            else
-            {
+            if (!boost::get<CNoDestination>(&coin_control.destChange)) {
+                scriptChange = GetScriptForDestination(coin_control.destChange);
+            } else { // no coin control: send change to newly generated address
                 // Note: We use a new key here to keep it from being obvious which side is the change.
                 //  The drawback is that by not reusing a previous key, the change may be lost if a
                 //  backup is restored, if the backup doesn't have the new private key for the change.
@@ -2654,7 +2651,7 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletT
                 if (pick_new_inputs) {
                     nValueIn = 0;
                     setCoins.clear();
-                    if (!SelectCoins(vAvailableCoins, nValueToSelect, setCoins, nValueIn, coinControl))
+                    if (!SelectCoins(vAvailableCoins, nValueToSelect, setCoins, nValueIn, &coin_control))
                     {
                         strFailReason = _("Insufficient funds");
                         return false;
@@ -2705,8 +2702,7 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletT
                 // to avoid conflicting with other possible uses of nSequence,
                 // and in the spirit of "smallest possible change from prior
                 // behavior."
-                bool rbf = coinControl ? coinControl->signalRbf : fWalletRbf;
-                const uint32_t nSequence = rbf ? MAX_BIP125_RBF_SEQUENCE : (std::numeric_limits<unsigned int>::max() - 1);
+                const uint32_t nSequence = coin_control.signalRbf ? MAX_BIP125_RBF_SEQUENCE : (std::numeric_limits<unsigned int>::max() - 1);
                 for (const auto& coin : setCoins)
                     txNew.vin.push_back(CTxIn(coin.outpoint,CScript(),
                                               nSequence));
@@ -2725,17 +2721,7 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletT
                     vin.scriptWitness.SetNull();
                 }
 
-                // Allow to override the default confirmation target over the CoinControl instance
-                int currentConfirmationTarget = nTxConfirmTarget;
-                if (coinControl && coinControl->nConfirmTarget > 0)
-                    currentConfirmationTarget = coinControl->nConfirmTarget;
-
-                // Allow to override the default fee estimate mode over the CoinControl instance
-                bool conservative_estimate = CalculateEstimateType(coinControl ? coinControl->m_fee_mode : FeeEstimateMode::UNSET, rbf);
-
-                CAmount nFeeNeeded = GetMinimumFee(nBytes, currentConfirmationTarget, ::mempool, ::feeEstimator, &feeCalc, false /* ignoreGlobalPayTxFee */, conservative_estimate);
-                if (coinControl && coinControl->fOverrideFeeRate)
-                    nFeeNeeded = coinControl->nFeeRate.GetFee(nBytes);
+                CAmount nFeeNeeded = GetMinimumFee(nBytes, coin_control, ::mempool, ::feeEstimator, &feeCalc);
 
                 // If we made it here and we aren't even able to meet the relay fee on the next pass, give up
                 // because we must be at the maximum allowed fee.
@@ -2760,7 +2746,7 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletT
                     // new inputs. We now know we only need the smaller fee
                     // (because of reduced tx size) and so we should add a
                     // change output. Only try this once.
-                    CAmount fee_needed_for_change = GetMinimumFee(change_prototype_size, currentConfirmationTarget, ::mempool, ::feeEstimator, nullptr, false /* ignoreGlobalPayTxFee */, conservative_estimate);
+                    CAmount fee_needed_for_change = GetMinimumFee(change_prototype_size, coin_control, ::mempool, ::feeEstimator, nullptr);
                     CAmount minimum_value_for_change = GetDustThreshold(change_prototype_txout, ::dustRelayFee);
                     CAmount max_excess_fee = fee_needed_for_change + minimum_value_for_change;
                     if (nFeeRet > nFeeNeeded + max_excess_fee && nChangePosInOut == -1 && nSubtractFeeFromAmount == 0 && pick_new_inputs) {
@@ -2936,33 +2922,61 @@ CAmount CWallet::GetRequiredFee(unsigned int nTxBytes)
     return std::max(minTxFee.GetFee(nTxBytes), ::minRelayTxFee.GetFee(nTxBytes));
 }
 
-CAmount CWallet::GetMinimumFee(unsigned int nTxBytes, unsigned int nConfirmTarget, const CTxMemPool& pool, const CBlockPolicyEstimator& estimator, FeeCalculation *feeCalc, bool ignoreGlobalPayTxFee, bool conservative_estimate)
+CAmount CWallet::GetMinimumFee(unsigned int nTxBytes, const CCoinControl& coin_control, const CTxMemPool& pool, const CBlockPolicyEstimator& estimator, FeeCalculation *feeCalc)
 {
-    // payTxFee is the user-set global for desired feerate
-    CAmount nFeeNeeded = payTxFee.GetFee(nTxBytes);
-    // User didn't set: use -txconfirmtarget to estimate...
-    if (nFeeNeeded == 0 || ignoreGlobalPayTxFee) {
-        nFeeNeeded = estimator.estimateSmartFee(nConfirmTarget, feeCalc, pool, conservative_estimate).GetFee(nTxBytes);
-        // ... unless we don't have enough mempool data for estimatefee, then use fallbackFee
-        if (nFeeNeeded == 0) {
-            nFeeNeeded = fallbackFee.GetFee(nTxBytes);
+    /* User control of how to calculate fee uses the following parameter precedence:
+       1. coin_control.m_feerate
+       2. coin_control.m_confirm_target
+       3. payTxFee (user-set global variable)
+       4. nTxConfirmTarget (user-set global variable)
+       The first parameter that is set is used.
+    */
+    CAmount fee_needed;
+    if (coin_control.m_feerate) { // 1.
+        fee_needed = coin_control.m_feerate->GetFee(nTxBytes);
+        if (feeCalc) feeCalc->reason = FeeReason::PAYTXFEE;
+        // Allow to override automatic min/max check over coin control instance
+        if (coin_control.fOverrideFeeRate) return fee_needed;
+    }
+    else if (!coin_control.m_confirm_target && ::payTxFee != CFeeRate(0)) { // 3. TODO: remove magic value of 0 for global payTxFee
+        fee_needed = ::payTxFee.GetFee(nTxBytes);
+        if (feeCalc) feeCalc->reason = FeeReason::PAYTXFEE;
+    }
+    else { // 2. or 4.
+        // We will use smart fee estimation
+        unsigned int target = coin_control.m_confirm_target ? *coin_control.m_confirm_target : ::nTxConfirmTarget;
+        // By default estimates are economical iff we are signaling opt-in-RBF
+        bool conservative_estimate = !coin_control.signalRbf;
+        // Allow to override the default fee estimate mode over the CoinControl instance
+        if (coin_control.m_fee_mode == FeeEstimateMode::CONSERVATIVE) conservative_estimate = true;
+        else if (coin_control.m_fee_mode == FeeEstimateMode::ECONOMICAL) conservative_estimate = false;
+
+        fee_needed = estimator.estimateSmartFee(target, feeCalc, conservative_estimate).GetFee(nTxBytes);
+        if (fee_needed == 0) {
+            // if we don't have enough data for estimateSmartFee, then use fallbackFee
+            fee_needed = fallbackFee.GetFee(nTxBytes);
             if (feeCalc) feeCalc->reason = FeeReason::FALLBACK;
         }
-    } else {
-        if (feeCalc) feeCalc->reason = FeeReason::PAYTXFEE;
+        // Obey mempool min fee when using smart fee estimation
+        CAmount min_mempool_fee = pool.GetMinFee(GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000).GetFee(nTxBytes);
+        if (fee_needed < min_mempool_fee) {
+            fee_needed = min_mempool_fee;
+            if (feeCalc) feeCalc->reason = FeeReason::MEMPOOL_MIN;
+        }
     }
+
     // prevent user from paying a fee below minRelayTxFee or minTxFee
-    CAmount requiredFee = GetRequiredFee(nTxBytes);
-    if (requiredFee > nFeeNeeded) {
-        nFeeNeeded = requiredFee;
+    CAmount required_fee = GetRequiredFee(nTxBytes);
+    if (required_fee > fee_needed) {
+        fee_needed = required_fee;
         if (feeCalc) feeCalc->reason = FeeReason::REQUIRED;
     }
     // But always obey the maximum
-    if (nFeeNeeded > maxTxFee) {
-        nFeeNeeded = maxTxFee;
+    if (fee_needed > maxTxFee) {
+        fee_needed = maxTxFee;
         if (feeCalc) feeCalc->reason = FeeReason::MAXTXFEE;
     }
-    return nFeeNeeded;
+    return fee_needed;
 }
 
 
@@ -4200,15 +4214,3 @@ bool CMerkleTx::AcceptToMemoryPool(const CAmount& nAbsurdFee, CValidationState&
 {
     return ::AcceptToMemoryPool(mempool, state, tx, true, NULL, NULL, false, nAbsurdFee);
 }
-
-bool CalculateEstimateType(FeeEstimateMode mode, bool opt_in_rbf) {
-    switch (mode) {
-    case FeeEstimateMode::UNSET:
-        return !opt_in_rbf; // Allow for lower fees if RBF is an option
-    case FeeEstimateMode::CONSERVATIVE:
-        return true;
-    case FeeEstimateMode::ECONOMICAL:
-        return false;
-    }
-    return true;
-}