Merge #10706: Improve wallet fee logic and fix GUI bugs

11590d3 Properly bound check conf_target in wallet RPC calls (Alex Morcos)
fd29d3d Remove checking of mempool min fee from estimateSmartFee. (Alex Morcos)
2fffaa9 Make QT fee displays use GetMinimumFee instead of estimateSmartFee (Alex Morcos)
1983ca6 Use CoinControl to pass custom fee setting from QT. (Alex Morcos)
03ee701 Refactor to use CoinControl in GetMinimumFee and FeeBumper (Alex Morcos)
ecd81df Make CoinControl a required argument to CreateTransaction (Alex Morcos)

Pull request description:

  This builds on #10589  (first 5 commits from that PR, last 5 commits are new)

  The first couple commits refactor to use the CCoinControl class to pass fee calculation parameters around.

  This allows for fixing the buggy interaction in QT between the global payTxFee which can be modified by the RPC call settxfee or temporarily modified by the QT custom fee settings.  Before these changes the GUI could sometimes send a transaction with a recently set payTxFee and not respect the settings displayed in the GUI.   After these changes, using the GUI does not involve the global transaction confirm target or payTxFee.

  The prospective fee displays in the smart fee slider and the coin control dialog are changed to use the fee calculation from GetMinimumFee, this simplifies the code and makes them slightly more correct in edge cases.

  Maxing the fee calculation with the mempool min fee is move from estimateSmartFee to GetMinimumFee.

  This fixes a long standing bug, and should be tagged for 0.15 as it is holding up finalizing the estimatesmartfee RPC API before release.

Tree-SHA512: 4d36a1bd5934aa62f3806d380fcafbef73e9fe5bdf190fc5259a3e3a13349e5ce796e50e7068c46dc630ccf56d061bce5804f0bfe2e082bb01ca725b63efd4c1

5 files changed, 37 insertions, 56 deletions

diff --git a/src/qt/coincontroldialog.cpp b/src/qt/coincontroldialog.cpp
index c19420beb5..f3ee0fbe39 100644
--- a/src/qt/coincontroldialog.cpp
+++ b/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)
     {
@@ -512,7 +510,7 @@ void CoinControlDialog::updateLabels(WalletModel *model, QDialog* dialog)
                 nBytes -= 34;
 
         // Fee
-        nPayFee = CWallet::GetMinimumFee(nBytes, coinControl->nConfirmTarget, ::mempool, ::feeEstimator, nullptr /* FeeCalculation */, false /* ignoreGlobalPayTxFee */, conservative_estimate);
+        nPayFee = CWallet::GetMinimumFee(nBytes, *coinControl, ::mempool, ::feeEstimator, nullptr /* FeeCalculation */);
 
         if (nPayAmount > 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->nConfirmTarget, 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);
diff --git a/src/qt/sendcoinsdialog.cpp b/src/qt/sendcoinsdialog.cpp
index 86401d3bb4..a01886c3ea 100644
--- a/src/qt/sendcoinsdialog.cpp
+++ b/src/qt/sendcoinsdialog.cpp
@@ -175,18 +175,13 @@ void SendCoinsDialog::setModel(WalletModel *_model)
             ui->confTargetSelector->addItem(tr("%1 (%2 blocks)").arg(GUIUtil::formatNiceTimeOffset(n*Params().GetConsensus().nPowTargetSpacing)).arg(n));
         }
         connect(ui->confTargetSelector, SIGNAL(currentIndexChanged(int)), this, SLOT(updateSmartFeeLabel()));
-        connect(ui->confTargetSelector, SIGNAL(currentIndexChanged(int)), this, SLOT(updateGlobalFeeVariables()));
         connect(ui->confTargetSelector, SIGNAL(currentIndexChanged(int)), this, SLOT(coinControlUpdateLabels()));
         connect(ui->groupFee, SIGNAL(buttonClicked(int)), this, SLOT(updateFeeSectionControls()));
-        connect(ui->groupFee, SIGNAL(buttonClicked(int)), this, SLOT(updateGlobalFeeVariables()));
         connect(ui->groupFee, SIGNAL(buttonClicked(int)), this, SLOT(coinControlUpdateLabels()));
-        connect(ui->groupCustomFee, SIGNAL(buttonClicked(int)), this, SLOT(updateGlobalFeeVariables()));
         connect(ui->groupCustomFee, SIGNAL(buttonClicked(int)), this, SLOT(coinControlUpdateLabels()));
-        connect(ui->customFee, SIGNAL(valueChanged()), this, SLOT(updateGlobalFeeVariables()));
         connect(ui->customFee, SIGNAL(valueChanged()), this, SLOT(coinControlUpdateLabels()));
         connect(ui->checkBoxMinimumFee, SIGNAL(stateChanged(int)), this, SLOT(setMinimumFee()));
         connect(ui->checkBoxMinimumFee, SIGNAL(stateChanged(int)), this, SLOT(updateFeeSectionControls()));
-        connect(ui->checkBoxMinimumFee, SIGNAL(stateChanged(int)), this, SLOT(updateGlobalFeeVariables()));
         connect(ui->checkBoxMinimumFee, SIGNAL(stateChanged(int)), this, SLOT(coinControlUpdateLabels()));
         connect(ui->optInRBF, SIGNAL(stateChanged(int)), this, SLOT(updateSmartFeeLabel()));
         connect(ui->optInRBF, SIGNAL(stateChanged(int)), this, SLOT(coinControlUpdateLabels()));
@@ -194,7 +189,6 @@ void SendCoinsDialog::setModel(WalletModel *_model)
         updateFeeSectionControls();
         updateMinFeeLabel();
         updateSmartFeeLabel();
-        updateGlobalFeeVariables();
 
         // set default rbf checkbox state
         ui->optInRBF->setCheckState(model->getDefaultWalletRbf() ? Qt::Checked : Qt::Unchecked);
@@ -274,14 +268,10 @@ void SendCoinsDialog::on_sendButton_clicked()
     CCoinControl ctrl;
     if (model->getOptionsModel()->getCoinControlFeatures())
         ctrl = *CoinControlDialog::coinControl;
-    if (ui->radioSmartFee->isChecked())
-        ctrl.nConfirmTarget = getConfTargetForIndex(ui->confTargetSelector->currentIndex());
-    else
-        ctrl.nConfirmTarget = 0;
 
-    ctrl.signalRbf = ui->optInRBF->isChecked();
+    updateCoinControlState(ctrl);
 
-    prepareStatus = model->prepareTransaction(currentTransaction, &ctrl);
+    prepareStatus = model->prepareTransaction(currentTransaction, ctrl);
 
     // process prepareStatus and on error generate message shown to user
     processSendCoinsReturn(prepareStatus,
@@ -636,18 +626,6 @@ void SendCoinsDialog::updateFeeSectionControls()
     ui->customFee               ->setEnabled(ui->radioCustomFee->isChecked() && !ui->checkBoxMinimumFee->isChecked());
 }
 
-void SendCoinsDialog::updateGlobalFeeVariables()
-{
-    if (ui->radioSmartFee->isChecked())
-    {
-        payTxFee = CFeeRate(0);
-    }
-    else
-    {
-        payTxFee = CFeeRate(ui->customFee->value());
-    }
-}
-
 void SendCoinsDialog::updateFeeMinimizedLabel()
 {
     if(!model || !model->getOptionsModel())
@@ -669,19 +647,32 @@ void SendCoinsDialog::updateMinFeeLabel()
         );
 }
 
+void SendCoinsDialog::updateCoinControlState(CCoinControl& ctrl)
+{
+    if (ui->radioCustomFee->isChecked()) {
+        ctrl.m_feerate = CFeeRate(ui->customFee->value());
+    } else {
+        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
+    ctrl.m_confirm_target = getConfTargetForIndex(ui->confTargetSelector->currentIndex());
+    ctrl.signalRbf = ui->optInRBF->isChecked();
+}
+
 void SendCoinsDialog::updateSmartFeeLabel()
 {
     if(!model || !model->getOptionsModel())
         return;
-
-    int nBlocksToConfirm = getConfTargetForIndex(ui->confTargetSelector->currentIndex());
+    CCoinControl coin_control;
+    updateCoinControlState(coin_control);
+    coin_control.m_feerate.reset(); // Explicitly use only fee estimation rate for smart fee labels
     FeeCalculation feeCalc;
-    bool conservative_estimate = CalculateEstimateType(FeeEstimateMode::UNSET, ui->optInRBF->isChecked());
-    CFeeRate feeRate = ::feeEstimator.estimateSmartFee(nBlocksToConfirm, &feeCalc, ::mempool, conservative_estimate);
-    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");
+    CFeeRate feeRate = CFeeRate(CWallet::GetMinimumFee(1000, coin_control, ::mempool, ::feeEstimator, &feeCalc));
+
+    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);
@@ -692,8 +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);
@@ -752,8 +741,6 @@ void SendCoinsDialog::coinControlFeatureChanged(bool checked)
     if (!checked && model) // coin control features disabled
         CoinControlDialog::coinControl->SetNull();
 
-    // make sure we set back the confirmation target
-    updateGlobalFeeVariables();
     coinControlUpdateLabels();
 }
 
@@ -844,15 +831,11 @@ void SendCoinsDialog::coinControlUpdateLabels()
     if (!model || !model->getOptionsModel())
         return;
 
+    updateCoinControlState(*CoinControlDialog::coinControl);
+
     // set pay amounts
     CoinControlDialog::payAmounts.clear();
     CoinControlDialog::fSubtractFeeFromAmount = false;
-    if (ui->radioSmartFee->isChecked()) {
-        CoinControlDialog::coinControl->nConfirmTarget = getConfTargetForIndex(ui->confTargetSelector->currentIndex());
-    } else {
-        CoinControlDialog::coinControl->nConfirmTarget = model->getDefaultConfirmTarget();
-    }
-    CoinControlDialog::coinControl->signalRbf = ui->optInRBF->isChecked();
 
     for(int i = 0; i < ui->entries->count(); ++i)
     {
diff --git a/src/qt/sendcoinsdialog.h b/src/qt/sendcoinsdialog.h
index ff7040ac5b..70b4aa5a03 100644
--- a/src/qt/sendcoinsdialog.h
+++ b/src/qt/sendcoinsdialog.h
@@ -68,6 +68,8 @@ private:
     void processSendCoinsReturn(const WalletModel::SendCoinsReturn &sendCoinsReturn, const QString &msgArg = QString());
     void minimizeFeeSection(bool fMinimize);
     void updateFeeMinimizedLabel();
+    // Update the passed in CCoinControl with state from the GUI
+    void updateCoinControlState(CCoinControl& ctrl);
 
 private Q_SLOTS:
     void on_sendButton_clicked();
@@ -91,7 +93,6 @@ private Q_SLOTS:
     void updateFeeSectionControls();
     void updateMinFeeLabel();
     void updateSmartFeeLabel();
-    void updateGlobalFeeVariables();
 
 Q_SIGNALS:
     // Fired when a message should be reported to the user
diff --git a/src/qt/walletmodel.cpp b/src/qt/walletmodel.cpp
index 60b55da3e7..ba0e1da0c7 100644
--- a/src/qt/walletmodel.cpp
+++ b/src/qt/walletmodel.cpp
@@ -24,6 +24,7 @@
 #include "sync.h"
 #include "ui_interface.h"
 #include "util.h" // for GetBoolArg
+#include "wallet/coincontrol.h"
 #include "wallet/feebumper.h"
 #include "wallet/wallet.h"
 #include "wallet/walletdb.h" // for BackupWallet
@@ -191,7 +192,7 @@ bool WalletModel::validateAddress(const QString &address)
     return addressParsed.IsValid();
 }
 
-WalletModel::SendCoinsReturn WalletModel::prepareTransaction(WalletModelTransaction &transaction, const CCoinControl *coinControl)
+WalletModel::SendCoinsReturn WalletModel::prepareTransaction(WalletModelTransaction &transaction, const CCoinControl& coinControl)
 {
     CAmount total = 0;
     bool fSubtractFeeFromAmount = false;
@@ -258,7 +259,7 @@ WalletModel::SendCoinsReturn WalletModel::prepareTransaction(WalletModelTransact
         return DuplicateAddress;
     }
 
-    CAmount nBalance = getBalance(coinControl);
+    CAmount nBalance = getBalance(&coinControl);
 
     if(total > nBalance)
     {
@@ -667,8 +668,10 @@ bool WalletModel::bumpFee(uint256 hash)
 {
     std::unique_ptr<CFeeBumper> feeBump;
     {
+        CCoinControl coin_control;
+        coin_control.signalRbf = true;
         LOCK2(cs_main, wallet->cs_wallet);
-        feeBump.reset(new CFeeBumper(wallet, hash, nTxConfirmTarget, false, 0, true, FeeEstimateMode::UNSET));
+        feeBump.reset(new CFeeBumper(wallet, hash, coin_control, 0));
     }
     if (feeBump->getResult() != BumpFeeResult::OK)
     {
diff --git a/src/qt/walletmodel.h b/src/qt/walletmodel.h
index 16b0caed4e..5258dc6699 100644
--- a/src/qt/walletmodel.h
+++ b/src/qt/walletmodel.h
@@ -154,7 +154,7 @@ public:
     };
 
     // prepare transaction for getting txfee before sending coins
-    SendCoinsReturn prepareTransaction(WalletModelTransaction &transaction, const CCoinControl *coinControl = NULL);
+    SendCoinsReturn prepareTransaction(WalletModelTransaction &transaction, const CCoinControl& coinControl);
 
     // Send coins to a list of recipients
     SendCoinsReturn sendCoins(WalletModelTransaction &transaction);