Make QT fee displays use GetMinimumFee instead of estimateSmartFee

Remove helper function (CalculateEstimateType) for determining whether
estimates should be conservative or not, now that this is only called
once from GetMinimumFee and incorporate the logic directly there.

src/qt/coincontroldialog.cpp

@@ -490,8 +490,6 @@ void CoinControlDialog::updateLabels(WalletModel *model, QDialog* dialog)
         else nBytesInputs += 148;
     }
 
-    bool conservative_estimate = CalculateEstimateType(FeeEstimateMode::UNSET, coinControl->signalRbf);
-
     // calculation
     if (nQuantity > 0)
     {
@@ -583,12 +581,8 @@ void CoinControlDialog::updateLabels(WalletModel *model, QDialog* dialog)
     QString toolTipDust = tr("This label turns red if any recipient receives an amount smaller than the current dust threshold.");
 
     // how many satoshis the estimated fee can vary per byte we guess wrong
-    double dFeeVary;
-    if (payTxFee.GetFeePerK() > 0)
-        dFeeVary = (double)std::max(CWallet::GetRequiredFee(1000), payTxFee.GetFeePerK()) / 1000;
-    else {
-        dFeeVary = (double)std::max(CWallet::GetRequiredFee(1000), ::feeEstimator.estimateSmartFee(*coinControl->m_confirm_target, NULL, ::mempool, conservative_estimate).GetFeePerK()) / 1000;
-    }
+    double dFeeVary = (double)nPayFee / nBytes;
+
     QString toolTip4 = tr("Can vary +/- %1 satoshi(s) per input.").arg(dFeeVary);
 
     l3->setToolTip(toolTip4);

src/qt/sendcoinsdialog.cpp

@@ -652,7 +652,7 @@ void SendCoinsDialog::updateCoinControlState(CCoinControl& ctrl)
     if (ui->radioCustomFee->isChecked()) {
         ctrl.m_feerate = CFeeRate(ui->customFee->value());
     } else {
-        ctrl.m_feerate = boost::none;
+        ctrl.m_feerate.reset();
     }
     // Avoid using global defaults when sending money from the GUI
     // Either custom fee will be used or if not selected, the confirmation target from dropdown box
@@ -666,15 +666,13 @@ void SendCoinsDialog::updateSmartFeeLabel()
         return;
     CCoinControl coin_control;
     updateCoinControlState(coin_control);
-    coin_control.m_feerate = boost::none; // Explicitly use only fee estimation rate for smart fee labels
+    coin_control.m_feerate.reset(); // Explicitly use only fee estimation rate for smart fee labels
     FeeCalculation feeCalc;
-    bool conservative_estimate = CalculateEstimateType(FeeEstimateMode::UNSET, coin_control.signalRbf);
-    CFeeRate feeRate = ::feeEstimator.estimateSmartFee(*coin_control.m_confirm_target, &feeCalc, ::mempool, conservative_estimate);
+    CFeeRate feeRate = CFeeRate(CWallet::GetMinimumFee(1000, coin_control, ::mempool, ::feeEstimator, &feeCalc));
 
-    if (feeRate <= CFeeRate(0)) // not enough data => minfee
-    {
-        ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(),
-                                                                std::max(CWallet::fallbackFee.GetFeePerK(), CWallet::GetRequiredFee(1000))) + "/kB");
+    ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), feeRate.GetFeePerK()) + "/kB");
+
+    if (feeCalc.reason == FeeReason::FALLBACK) {
         ui->labelSmartFee2->show(); // (Smart fee not initialized yet. This usually takes a few blocks...)
         ui->labelFeeEstimation->setText("");
         ui->fallbackFeeWarningLabel->setVisible(true);
@@ -685,8 +683,6 @@ void SendCoinsDialog::updateSmartFeeLabel()
     }
     else
     {
-        ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(),
-                                                                std::max(feeRate.GetFeePerK(), CWallet::GetRequiredFee(1000))) + "/kB");
         ui->labelSmartFee2->hide();
         ui->labelFeeEstimation->setText(tr("Estimated to begin confirmation within %n block(s).", "", feeCalc.returnedTarget));
         ui->fallbackFeeWarningLabel->setVisible(false);

src/wallet/coincontrol.h

@@ -43,9 +43,9 @@ public:
         fAllowOtherInputs = false;
         fAllowWatchOnly = false;
         setSelected.clear();
-        m_feerate = boost::none;
+        m_feerate.reset();
         fOverrideFeeRate = false;
-        m_confirm_target = boost::none;
+        m_confirm_target.reset();
         signalRbf = fWalletRbf;
         m_fee_mode = FeeEstimateMode::UNSET;
     }

src/wallet/wallet.cpp

@@ -2945,8 +2945,11 @@ CAmount CWallet::GetMinimumFee(unsigned int nTxBytes, const CCoinControl& coin_c
     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
-        bool conservative_estimate = CalculateEstimateType(coin_control.m_fee_mode, coin_control.signalRbf);
+        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, pool, conservative_estimate).GetFee(nTxBytes);
         if (fee_needed == 0) {
@@ -4194,15 +4197,3 @@ 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;
-}

src/wallet/wallet.h

@@ -1213,6 +1213,4 @@ bool CWallet::DummySignTx(CMutableTransaction &txNew, const ContainerType &coins
     return true;
 }
 
-bool CalculateEstimateType(FeeEstimateMode mode, bool opt_in_rbf);
-
 #endif // BITCOIN_WALLET_WALLET_H