Merge pull request #6887

53238ff Clarify what minrelaytxfee does (MarcoFalke)
abd8b76 [qt] Properly display required fee instead of minTxFee (MarcoFalke)

src/init.cpp

@@ -439,7 +439,7 @@ std::string HelpMessage(HelpMessageMode mode)
         strUsage += HelpMessageOpt("-relaypriority", strprintf("Require high priority for relaying free or low-fee transactions (default: %u)", 1));
         strUsage += HelpMessageOpt("-maxsigcachesize=<n>", strprintf("Limit size of signature cache to <n> entries (default: %u)", 50000));
     }
-    strUsage += HelpMessageOpt("-minrelaytxfee=<amt>", strprintf(_("Fees (in %s/kB) smaller than this are considered zero fee for relaying (default: %s)"),
+    strUsage += HelpMessageOpt("-minrelaytxfee=<amt>", strprintf(_("Fees (in %s/kB) smaller than this are considered zero fee for relaying, mining and transaction creation (default: %s)"),
         CURRENCY_UNIT, FormatMoney(::minRelayTxFee.GetFeePerK())));
     strUsage += HelpMessageOpt("-printtoconsole", _("Send trace/debug info to console instead of debug.log file"));
     if (showDebug)

src/main.cpp

@@ -74,7 +74,7 @@ size_t nCoinCacheUsage = 5000 * 300;
 uint64_t nPruneTarget = 0;
 bool fAlerts = DEFAULT_ALERTS;
 
-/** Fees smaller than this (in satoshi) are considered zero fee (for relaying and mining) */
+/** Fees smaller than this (in satoshi) are considered zero fee (for relaying, mining and transaction creation) */
 CFeeRate minRelayTxFee = CFeeRate(1000);
 
 CTxMemPool mempool(::minRelayTxFee);

src/qt/coincontroldialog.cpp

@@ -636,21 +636,21 @@ void CoinControlDialog::updateLabels(WalletModel *model, QDialog* dialog)
 
     // tool tips
     QString toolTip1 = tr("This label turns red if the transaction size is greater than 1000 bytes.") + "<br /><br />";
-    toolTip1 += tr("This means a fee of at least %1 per kB is required.").arg(BitcoinUnits::formatWithUnit(nDisplayUnit, CWallet::minTxFee.GetFeePerK())) + "<br /><br />";
+    toolTip1 += tr("This means a fee of at least %1 per kB is required.").arg(BitcoinUnits::formatWithUnit(nDisplayUnit, CWallet::GetRequiredFee(1000))) + "<br /><br />";
     toolTip1 += tr("Can vary +/- 1 byte per input.");
 
     QString toolTip2 = tr("Transactions with higher priority are more likely to get included into a block.") + "<br /><br />";
     toolTip2 += tr("This label turns red if the priority is smaller than \"medium\".") + "<br /><br />";
-    toolTip2 += tr("This means a fee of at least %1 per kB is required.").arg(BitcoinUnits::formatWithUnit(nDisplayUnit, CWallet::minTxFee.GetFeePerK()));
+    toolTip2 += tr("This means a fee of at least %1 per kB is required.").arg(BitcoinUnits::formatWithUnit(nDisplayUnit, CWallet::GetRequiredFee(1000)));
 
     QString toolTip3 = tr("This label turns red if any recipient receives an amount smaller than %1.").arg(BitcoinUnits::formatWithUnit(nDisplayUnit, ::minRelayTxFee.GetFee(546)));
 
     // how many satoshis the estimated fee can vary per byte we guess wrong
     double dFeeVary;
     if (payTxFee.GetFeePerK() > 0)
-        dFeeVary = (double)std::max(CWallet::minTxFee.GetFeePerK(), payTxFee.GetFeePerK()) / 1000;
+        dFeeVary = (double)std::max(CWallet::GetRequiredFee(1000), payTxFee.GetFeePerK()) / 1000;
     else
-        dFeeVary = (double)std::max(CWallet::minTxFee.GetFeePerK(), mempool.estimateFee(nTxConfirmTarget).GetFeePerK()) / 1000;
+        dFeeVary = (double)std::max(CWallet::GetRequiredFee(1000), mempool.estimateFee(nTxConfirmTarget).GetFeePerK()) / 1000;
     QString toolTip4 = tr("Can vary +/- %1 satoshi(s) per input.").arg(dFeeVary);
 
     l3->setToolTip(toolTip4);

src/qt/optionsdialog.cpp

@@ -18,7 +18,7 @@
 #include "txdb.h" // for -dbcache defaults
 
 #ifdef ENABLE_WALLET
-#include "wallet/wallet.h" // for CWallet::minTxFee
+#include "wallet/wallet.h" // for CWallet::GetRequiredFee()
 #endif
 
 #include <boost/thread.hpp>

src/qt/sendcoinsdialog.cpp

@@ -172,7 +172,7 @@ void SendCoinsDialog::setModel(WalletModel *model)
         connect(ui->checkBoxMinimumFee, SIGNAL(stateChanged(int)), this, SLOT(coinControlUpdateLabels()));
         connect(ui->checkBoxFreeTx, SIGNAL(stateChanged(int)), this, SLOT(updateGlobalFeeVariables()));
         connect(ui->checkBoxFreeTx, SIGNAL(stateChanged(int)), this, SLOT(coinControlUpdateLabels()));
-        ui->customFee->setSingleStep(CWallet::minTxFee.GetFeePerK());
+        ui->customFee->setSingleStep(CWallet::GetRequiredFee(1000));
         updateFeeSectionControls();
         updateMinFeeLabel();
         updateSmartFeeLabel();
@@ -569,7 +569,7 @@ void SendCoinsDialog::on_buttonMinimizeFee_clicked()
 void SendCoinsDialog::setMinimumFee()
 {
     ui->radioCustomPerKilobyte->setChecked(true);
-    ui->customFee->setValue(CWallet::minTxFee.GetFeePerK());
+    ui->customFee->setValue(CWallet::GetRequiredFee(1000));
 }
 
 void SendCoinsDialog::updateFeeSectionControls()
@@ -621,8 +621,8 @@ void SendCoinsDialog::updateFeeMinimizedLabel()
 void SendCoinsDialog::updateMinFeeLabel()
 {
     if (model && model->getOptionsModel())
-        ui->checkBoxMinimumFee->setText(tr("Pay only the minimum fee of %1").arg(
-            BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), CWallet::minTxFee.GetFeePerK()) + "/kB")
+        ui->checkBoxMinimumFee->setText(tr("Pay only the required fee of %1").arg(
+            BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), CWallet::GetRequiredFee(1000)) + "/kB")
         );
 }
 
@@ -635,7 +635,7 @@ void SendCoinsDialog::updateSmartFeeLabel()
     CFeeRate feeRate = mempool.estimateFee(nBlocksToConfirm);
     if (feeRate <= CFeeRate(0)) // not enough data => minfee
     {
-        ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), CWallet::minTxFee.GetFeePerK()) + "/kB");
+        ui->labelSmartFee->setText(BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), CWallet::GetRequiredFee(1000)) + "/kB");
         ui->labelSmartFee2->show(); // (Smart fee not initialized yet. This usually takes a few blocks...)
         ui->labelFeeEstimation->setText("");
     }

src/wallet/wallet.cpp

@@ -2118,6 +2118,11 @@ bool CWallet::CommitTransaction(CWalletTx& wtxNew, CReserveKey& reservekey)
     return true;
 }
 
+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)
 {
     // payTxFee is user-set "I want to pay this much"
@@ -2129,9 +2134,9 @@ CAmount CWallet::GetMinimumFee(unsigned int nTxBytes, unsigned int nConfirmTarge
     if (nFeeNeeded == 0)
         nFeeNeeded = pool.estimateFee(nConfirmTarget).GetFee(nTxBytes);
     // ... unless we don't have enough mempool data, in which case fall
-    // back to a hard-coded fee
+    // back to the required fee
     if (nFeeNeeded == 0)
-        nFeeNeeded = minTxFee.GetFee(nTxBytes);
+        nFeeNeeded = GetRequiredFee(nTxBytes);
     // prevent user from paying a non-sense fee (like 1 satoshi): 0 < fee < minRelayFee
     if (nFeeNeeded < ::minRelayTxFee.GetFee(nTxBytes))
         nFeeNeeded = ::minRelayTxFee.GetFee(nTxBytes);

src/wallet/wallet.h

@@ -657,7 +657,16 @@ public:
     bool CommitTransaction(CWalletTx& wtxNew, CReserveKey& reservekey);
 
     static CFeeRate minTxFee;
+    /**
+     * Estimate the minimum fee considering user set parameters
+     * and the required fee
+     */
     static CAmount GetMinimumFee(unsigned int nTxBytes, unsigned int nConfirmTarget, const CTxMemPool& pool);
+    /**
+     * Return the minimum required fee taking into account the
+     * floating relay fee and user set minimum transaction fee
+     */
+    static CAmount GetRequiredFee(unsigned int nTxBytes);
 
     bool NewKeyPool();
     bool TopUpKeyPool(unsigned int kpSize = 0);