Undo GetMinFee-requires-extra-call-to-hit-0

src/test/mempool_tests.cpp

@@ -428,7 +428,6 @@ BOOST_AUTO_TEST_CASE(MempoolSizeLimitTest)
     // ... but feerate should never drop below 1000
 
     SetMockTime(42 + 8*CTxMemPool::ROLLING_FEE_HALFLIFE + CTxMemPool::ROLLING_FEE_HALFLIFE/2 + CTxMemPool::ROLLING_FEE_HALFLIFE/4);
-    pool.GetMinFee(1);
     BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(), 0);
     // ... unless it has gone all the way to 0 (after getting past 1000/2)
 

src/txmempool.cpp

@@ -879,8 +879,10 @@ CFeeRate CTxMemPool::GetMinFee(size_t sizelimit) const {
         rollingMinimumFeeRate = rollingMinimumFeeRate / pow(2.0, (time - lastRollingFeeUpdate) / halflife);
         lastRollingFeeUpdate = time;
 
-        if (rollingMinimumFeeRate < minReasonableRelayFee.GetFeePerK() / 2)
+        if (rollingMinimumFeeRate < minReasonableRelayFee.GetFeePerK() / 2) {
             rollingMinimumFeeRate = 0;
+            return CFeeRate(0);
+        }
     }
     return std::max(CFeeRate(rollingMinimumFeeRate), minReasonableRelayFee);
 }