Remove checking of mempool min fee from estimateSmartFee.

This check has been moved to the wallet logic GetMinimumFee. The rpc call to
estimatesmartfee will now no longer return a result maxed with the mempool min
fee, but automated fee calculations from the wallet will produce the same result
as before and coincontrol and sendcoins dialogs in the GUI will correctly
display the right prospective fee.

changes to policy/fees.cpp include a big whitespace indentation change.

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;
@@ -835,8 +837,6 @@ 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())
@@ -898,17 +898,9 @@ CFeeRate CBlockPolicyEstimator::estimateSmartFee(int confTarget, FeeCalculation
             }
         }
     }
-    } // 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);
 

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

src/rpc/mining.cpp

@@ -815,7 +815,6 @@ UniValue estimatesmartfee(const JSONRPCRequest& request)
             "\n"
             "A negative value is returned if not enough transactions and blocks\n"
             "have been observed to make an estimate for any number of blocks.\n"
-            "However it will not return a value below the mempool reject fee.\n"
             "\nExample:\n"
             + HelpExampleCli("estimatesmartfee", "6")
             );
@@ -831,7 +830,7 @@ UniValue estimatesmartfee(const JSONRPCRequest& request)
 
     UniValue result(UniValue::VOBJ);
     FeeCalculation feeCalc;
-    CFeeRate feeRate = ::feeEstimator.estimateSmartFee(nBlocks, &feeCalc, ::mempool, conservative);
+    CFeeRate feeRate = ::feeEstimator.estimateSmartFee(nBlocks, &feeCalc, conservative);
     result.push_back(Pair("feerate", feeRate == CFeeRate(0) ? -1.0 : ValueFromAmount(feeRate.GetFeePerK())));
     result.push_back(Pair("blocks", feeCalc.returnedTarget));
     return result;

src/test/policyestimator_tests.cpp

@@ -177,16 +177,6 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
     for (int i = 2; i < 9; i++) { // At 9, the original estimate was already at the bottom (b/c scale = 2)
         BOOST_CHECK(feeEst.estimateFee(i).GetFeePerK() < origFeeEst[i-1] - deltaFee);
     }
-
-    // Test that if the mempool is limited, estimateSmartFee won't return a value below the mempool min fee
-    mpool.addUnchecked(tx.GetHash(),  entry.Fee(feeV[5]).Time(GetTime()).Height(blocknum).FromTx(tx));
-    // evict that transaction which should set a mempool min fee of minRelayTxFee + feeV[5]
-    mpool.TrimToSize(1);
-    BOOST_CHECK(mpool.GetMinFee(1).GetFeePerK() > feeV[5]);
-    for (int i = 1; i < 10; i++) {
-        BOOST_CHECK(feeEst.estimateSmartFee(i, NULL, mpool, true).GetFeePerK() >= feeEst.estimateRawFee(i, 0.85, FeeEstimateHorizon::MED_HALFLIFE).GetFeePerK());
-        BOOST_CHECK(feeEst.estimateSmartFee(i, NULL, mpool, true).GetFeePerK() >= mpool.GetMinFee(1).GetFeePerK());
-    }
 }
 
 BOOST_AUTO_TEST_SUITE_END()

src/wallet/wallet.cpp

@@ -2951,12 +2951,18 @@ CAmount CWallet::GetMinimumFee(unsigned int nTxBytes, const CCoinControl& coin_c
         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);
+        fee_needed = estimator.estimateSmartFee(target, feeCalc, conservative_estimate).GetFee(nTxBytes);
         if (fee_needed == 0) {
             // if we don't have enough data for estimateSmartFee, then use fallbackFee
             fee_needed = fallbackFee.GetFee(nTxBytes);
             if (feeCalc) feeCalc->reason = FeeReason::FALLBACK;
         }
+        // Obey mempool min fee when using smart fee estimation
+        CAmount min_mempool_fee = pool.GetMinFee(GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000).GetFee(nTxBytes);
+        if (fee_needed < min_mempool_fee) {
+            fee_needed = min_mempool_fee;
+            if (feeCalc) feeCalc->reason = FeeReason::MEMPOOL_MIN;
+        }
     }
 
     // prevent user from paying a fee below minRelayTxFee or minTxFee