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

2 files changed, 52 insertions, 60 deletions

diff --git a/src/policy/fees.cpp b/src/policy/fees.cpp
index dbdc5013f0..0f186fa845 100644
--- a/src/policy/fees.cpp
+++ b/src/policy/fees.cpp
@@ -826,8 +826,10 @@ double CBlockPolicyEstimator::estimateConservativeFee(unsigned int doubleTarget,
  * estimates, however, required the 95% threshold at 2 * target be met for any
  * longer time horizons also.
  */
-CFeeRate CBlockPolicyEstimator::estimateSmartFee(int confTarget, FeeCalculation *feeCalc, const CTxMemPool& pool, bool conservative) const
+CFeeRate CBlockPolicyEstimator::estimateSmartFee(int confTarget, FeeCalculation *feeCalc, bool conservative) const
 {
+    LOCK(cs_feeEstimator);
+
     if (feeCalc) {
         feeCalc->desiredTarget = confTarget;
         feeCalc->returnedTarget = confTarget;
@@ -835,80 +837,70 @@ CFeeRate CBlockPolicyEstimator::estimateSmartFee(int confTarget, FeeCalculation
 
     double median = -1;
     EstimationResult tempResult;
-    {
-        LOCK(cs_feeEstimator);
 
-        // Return failure if trying to analyze a target we're not tracking
-        if (confTarget <= 0 || (unsigned int)confTarget > longStats->GetMaxConfirms())
-            return CFeeRate(0);
+    // Return failure if trying to analyze a target we're not tracking
+    if (confTarget <= 0 || (unsigned int)confTarget > longStats->GetMaxConfirms())
+        return CFeeRate(0);
 
-        // It's not possible to get reasonable estimates for confTarget of 1
-        if (confTarget == 1)
-            confTarget = 2;
+    // It's not possible to get reasonable estimates for confTarget of 1
+    if (confTarget == 1)
+        confTarget = 2;
 
-        unsigned int maxUsableEstimate = MaxUsableEstimate();
-        if (maxUsableEstimate <= 1)
-            return CFeeRate(0);
+    unsigned int maxUsableEstimate = MaxUsableEstimate();
+    if (maxUsableEstimate <= 1)
+        return CFeeRate(0);
 
-        if ((unsigned int)confTarget > maxUsableEstimate) {
-            confTarget = maxUsableEstimate;
-        }
+    if ((unsigned int)confTarget > maxUsableEstimate) {
+        confTarget = maxUsableEstimate;
+    }
 
-        assert(confTarget > 0); //estimateCombinedFee and estimateConservativeFee take unsigned ints
-        /** true is passed to estimateCombined fee for target/2 and target so
-         * that we check the max confirms for shorter time horizons as well.
-         * This is necessary to preserve monotonically increasing estimates.
-         * For non-conservative estimates we do the same thing for 2*target, but
-         * for conservative estimates we want to skip these shorter horizons
-         * checks for 2*target because we are taking the max over all time
-         * horizons so we already have monotonically increasing estimates and
-         * the purpose of conservative estimates is not to let short term
-         * fluctuations lower our estimates by too much.
-         */
-        double halfEst = estimateCombinedFee(confTarget/2, HALF_SUCCESS_PCT, true, &tempResult);
+    assert(confTarget > 0); //estimateCombinedFee and estimateConservativeFee take unsigned ints
+    /** true is passed to estimateCombined fee for target/2 and target so
+     * that we check the max confirms for shorter time horizons as well.
+     * This is necessary to preserve monotonically increasing estimates.
+     * For non-conservative estimates we do the same thing for 2*target, but
+     * for conservative estimates we want to skip these shorter horizons
+     * checks for 2*target because we are taking the max over all time
+     * horizons so we already have monotonically increasing estimates and
+     * the purpose of conservative estimates is not to let short term
+     * fluctuations lower our estimates by too much.
+     */
+    double halfEst = estimateCombinedFee(confTarget/2, HALF_SUCCESS_PCT, true, &tempResult);
+    if (feeCalc) {
+        feeCalc->est = tempResult;
+        feeCalc->reason = FeeReason::HALF_ESTIMATE;
+    }
+    median = halfEst;
+    double actualEst = estimateCombinedFee(confTarget, SUCCESS_PCT, true, &tempResult);
+    if (actualEst > median) {
+        median = actualEst;
         if (feeCalc) {
             feeCalc->est = tempResult;
-            feeCalc->reason = FeeReason::HALF_ESTIMATE;
+            feeCalc->reason = FeeReason::FULL_ESTIMATE;
         }
-        median = halfEst;
-        double actualEst = estimateCombinedFee(confTarget, SUCCESS_PCT, true, &tempResult);
-        if (actualEst > median) {
-            median = actualEst;
-            if (feeCalc) {
-                feeCalc->est = tempResult;
-                feeCalc->reason = FeeReason::FULL_ESTIMATE;
-            }
+    }
+    double doubleEst = estimateCombinedFee(2 * confTarget, DOUBLE_SUCCESS_PCT, !conservative, &tempResult);
+    if (doubleEst > median) {
+        median = doubleEst;
+        if (feeCalc) {
+            feeCalc->est = tempResult;
+            feeCalc->reason = FeeReason::DOUBLE_ESTIMATE;
         }
-        double doubleEst = estimateCombinedFee(2 * confTarget, DOUBLE_SUCCESS_PCT, !conservative, &tempResult);
-        if (doubleEst > median) {
-            median = doubleEst;
+    }
+
+    if (conservative || median == -1) {
+        double consEst =  estimateConservativeFee(2 * confTarget, &tempResult);
+        if (consEst > median) {
+            median = consEst;
             if (feeCalc) {
                 feeCalc->est = tempResult;
-                feeCalc->reason = FeeReason::DOUBLE_ESTIMATE;
+                feeCalc->reason = FeeReason::CONSERVATIVE;
             }
         }
-
-        if (conservative || median == -1) {
-            double consEst =  estimateConservativeFee(2 * confTarget, &tempResult);
-            if (consEst > median) {
-                median = consEst;
-                if (feeCalc) {
-                    feeCalc->est = tempResult;
-                    feeCalc->reason = FeeReason::CONSERVATIVE;
-                }
-            }
-        }
-    } // Must unlock cs_feeEstimator before taking mempool locks
+    }
 
     if (feeCalc) feeCalc->returnedTarget = confTarget;
 
-    // If mempool is limiting txs , return at least the min feerate from the mempool
-    CAmount minPoolFee = pool.GetMinFee(GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000).GetFeePerK();
-    if (minPoolFee > 0 && minPoolFee > median) {
-        if (feeCalc) feeCalc->reason = FeeReason::MEMPOOL_MIN;
-        return CFeeRate(minPoolFee);
-    }
-
     if (median < 0)
         return CFeeRate(0);
 
diff --git a/src/policy/fees.h b/src/policy/fees.h
index 4c80371c5c..f4ef793643 100644
--- a/src/policy/fees.h
+++ b/src/policy/fees.h
@@ -208,7 +208,7 @@ public:
      *  the closest target where one can be given.  'conservative' estimates are
      *  valid over longer time horizons also.
      */
-    CFeeRate estimateSmartFee(int confTarget, FeeCalculation *feeCalc, const CTxMemPool& pool, bool conservative) const;
+    CFeeRate estimateSmartFee(int confTarget, FeeCalculation *feeCalc, bool conservative) const;
 
     /** Return a specific fee estimate calculation with a given success
      * threshold and time horizon, and optionally return detailed data about