Merge pull request #7096

ff723da [Qt] improve minimum absolute fee option - Only display the minimum absolute fee control if CoinControl is enabled (Jonas Schnelli)
31b508a [Qt] make use of the nMinimumTotalFee (absolute) in coincontrols fee calculation (Jonas Schnelli)
80462dd [Qt] use ASYMP_UTF8 (≈) whenever we show a fee that is not absolute (Jonas Schnelli)
ecc7c82 Move fPayAtLeastCustomFee function to CC (Pieter Wuille)

src/coincontrol.h

@@ -16,6 +16,8 @@ public:
     bool fAllowOtherInputs;
     //! Includes watch only addresses which match the ISMINE_WATCH_SOLVABLE criteria
     bool fAllowWatchOnly;
+    //! Minimum absolute fee (not per kilobyte)
+    CAmount nMinimumTotalFee;
 
     CCoinControl()
     {
@@ -28,6 +30,7 @@ public:
         fAllowOtherInputs = false;
         fAllowWatchOnly = false;
         setSelected.clear();
+        nMinimumTotalFee = 0;
     }
 
     bool HasSelected() const

src/qt/coincontroldialog.cpp

@@ -549,6 +549,9 @@ void CoinControlDialog::updateLabels(WalletModel *model, QDialog* dialog)
 
         // Fee
         nPayFee = CWallet::GetMinimumFee(nBytes, nTxConfirmTarget, mempool);
+        if (nPayFee > 0 && coinControl->nMinimumTotalFee > nPayFee)
+            nPayFee = coinControl->nMinimumTotalFee;
+
 
         // Allow free? (require at least hard-coded threshold and default to that if no estimate)
         double dPriorityNeeded = std::max(mempoolEstimatePriority, AllowFreeThreshold());
@@ -619,7 +622,7 @@ void CoinControlDialog::updateLabels(WalletModel *model, QDialog* dialog)
     l6->setText(sPriorityLabel);                                             // Priority
     l7->setText(fDust ? tr("yes") : tr("no"));                               // Dust
     l8->setText(BitcoinUnits::formatWithUnit(nDisplayUnit, nChange));        // Change
-    if (nPayFee > 0 && !(payTxFee.GetFeePerK() > 0 && fPayAtLeastCustomFee && nBytes < 1000))
+    if (nPayFee > 0 && (coinControl->nMinimumTotalFee < nPayFee))
     {
         l3->setText(ASYMP_UTF8 + l3->text());
         l4->setText(ASYMP_UTF8 + l4->text());

src/qt/sendcoinsdialog.cpp

@@ -585,7 +585,7 @@ void SendCoinsDialog::updateFeeSectionControls()
     ui->checkBoxMinimumFee      ->setEnabled(ui->radioCustomFee->isChecked());
     ui->labelMinFeeWarning      ->setEnabled(ui->radioCustomFee->isChecked());
     ui->radioCustomPerKilobyte  ->setEnabled(ui->radioCustomFee->isChecked() && !ui->checkBoxMinimumFee->isChecked());
-    ui->radioCustomAtLeast      ->setEnabled(ui->radioCustomFee->isChecked() && !ui->checkBoxMinimumFee->isChecked());
+    ui->radioCustomAtLeast      ->setEnabled(ui->radioCustomFee->isChecked() && !ui->checkBoxMinimumFee->isChecked() && CoinControlDialog::coinControl->HasSelected());
     ui->customFee               ->setEnabled(ui->radioCustomFee->isChecked() && !ui->checkBoxMinimumFee->isChecked());
 }
 
@@ -600,7 +600,10 @@ void SendCoinsDialog::updateGlobalFeeVariables()
     {
         nTxConfirmTarget = defaultConfirmTarget;
         payTxFee = CFeeRate(ui->customFee->value());
-        fPayAtLeastCustomFee = ui->radioCustomAtLeast->isChecked();
+
+        // if user has selected to set a minimum absolute fee, pass the value to coincontrol
+        // set nMinimumTotalFee to 0 in case of user has selected that the fee is per KB
+        CoinControlDialog::coinControl->nMinimumTotalFee = ui->radioCustomAtLeast->isChecked() ? ui->customFee->value() : 0;
     }
 
     fSendFreeTransactions = ui->checkBoxFreeTx->isChecked();
@@ -707,7 +710,6 @@ void SendCoinsDialog::coinControlFeatureChanged(bool checked)
     if (!checked && model) // coin control features disabled
         CoinControlDialog::coinControl->SetNull();
 
-    if (checked)
     coinControlUpdateLabels();
 }
 
@@ -782,9 +784,24 @@ void SendCoinsDialog::coinControlChangeEdited(const QString& text)
 // Coin Control: update labels
 void SendCoinsDialog::coinControlUpdateLabels()
 {
-    if (!model || !model->getOptionsModel() || !model->getOptionsModel()->getCoinControlFeatures())
+    if (!model || !model->getOptionsModel())
         return;
 
+    if (model->getOptionsModel()->getCoinControlFeatures())
+    {
+        // enable minium absolute fee UI controls
+        ui->radioCustomAtLeast->setVisible(true);
+
+        // only enable the feature if inputs are selected
+        ui->radioCustomAtLeast->setEnabled(CoinControlDialog::coinControl->HasSelected());
+    }
+    else
+    {
+        // in case coin control is disabled (=default), hide minimum absolute fee UI controls
+        ui->radioCustomAtLeast->setVisible(false);
+        return;
+    }
+
     // set pay amounts
     CoinControlDialog::payAmounts.clear();
     CoinControlDialog::fSubtractFeeFromAmount = false;

src/wallet/wallet.cpp

@@ -41,7 +41,6 @@ CAmount maxTxFee = DEFAULT_TRANSACTION_MAXFEE;
 unsigned int nTxConfirmTarget = DEFAULT_TX_CONFIRM_TARGET;
 bool bSpendZeroConfChange = DEFAULT_SPEND_ZEROCONF_CHANGE;
 bool fSendFreeTransactions = DEFAULT_SEND_FREE_TRANSACTIONS;
-bool fPayAtLeastCustomFee = false;
 
 /**
  * Fees smaller than this (in satoshi) are considered zero fee (for transaction creation)
@@ -2096,6 +2095,9 @@ bool CWallet::CreateTransaction(const vector<CRecipient>& vecSend, CWalletTx& wt
                 }
 
                 CAmount nFeeNeeded = GetMinimumFee(nBytes, nTxConfirmTarget, mempool);
+                if (coinControl && nFeeNeeded > 0 && coinControl->nMinimumTotalFee > nFeeNeeded) {
+                    nFeeNeeded = coinControl->nMinimumTotalFee;
+                }
 
                 // 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.
@@ -2191,9 +2193,6 @@ CAmount CWallet::GetMinimumFee(unsigned int nTxBytes, unsigned int nConfirmTarge
 {
     // payTxFee is user-set "I want to pay this much"
     CAmount nFeeNeeded = payTxFee.GetFee(nTxBytes);
-    // user selected total at least (default=true)
-    if (fPayAtLeastCustomFee && nFeeNeeded > 0 && nFeeNeeded < payTxFee.GetFeePerK())
-        nFeeNeeded = payTxFee.GetFeePerK();
     // User didn't set: use -txconfirmtarget to estimate...
     if (nFeeNeeded == 0) {
         int estimateFoundTarget = nConfirmTarget;

src/wallet/wallet.h

@@ -35,7 +35,6 @@ extern CAmount maxTxFee;
 extern unsigned int nTxConfirmTarget;
 extern bool bSpendZeroConfChange;
 extern bool fSendFreeTransactions;
-extern bool fPayAtLeastCustomFee;
 
 static const unsigned int DEFAULT_KEYPOOL_SIZE = 100;
 //! -paytxfee default