Improve comments per review

src/rpcmining.cpp

@@ -45,16 +45,13 @@ Value GetNetworkHashPS(int lookup, int height) {
     if (pb == NULL || !pb->nHeight)
         return 0;
 
-    // If lookup is -1, then use difficulty averaging window.
+    // If lookup is nonpositive, then use difficulty averaging window.
     if (lookup <= 0)
         lookup = pb->nHeight - Params().GetConsensus().nPowAveragingWindow;
 
-    // If lookup is still negative, then use blocks since genesis.
-    if (lookup <= 0)
-        lookup = pb->nHeight;
-
-    // If lookup is larger than chain, then set it to chain length.
-    if (lookup > pb->nHeight)
+    // If lookup is still nonpositive, or is larger than chain, then set it to
+    // chain length.
+    if (lookup <= 0 || lookup > pb->nHeight)
         lookup = pb->nHeight;
 
     CBlockIndex *pb0 = pb;

src/test/miner_tests.cpp

@@ -158,7 +158,11 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
 
         CBlock *pblock = &pblocktemplate->block; // pointer for convenience
         pblock->nVersion = 4;
-        // Fake the blocks taking at least nPowTargetSpacing
+        // Fake the blocks taking at least nPowTargetSpacing to be mined.
+        // GetMedianTimePast() returns the median of 11 blocks, so the timestamp
+        // of the next block must be six spacings ahead of that to be at least
+        // one spacing ahead of the tip. Within 11 blocks of genesis, the median
+        // will be closer to the tip, and blocks will appear slower.
         pblock->nTime = chainActive.Tip()->GetMedianTimePast()+6*Params().GetConsensus().nPowTargetSpacing;
         CMutableTransaction txCoinbase(pblock->vtx[0]);
         txCoinbase.vin[0].scriptSig = CScript() << (chainActive.Height()+1) << OP_0;

src/test/pow_tests.cpp

@@ -22,7 +22,7 @@ BOOST_AUTO_TEST_CASE(get_next_work)
     int64_t nLastRetargetTime = 1262149169; // NOTE: Not an actual block time
     CBlockIndex pindexLast;
     pindexLast.nHeight = 32255;
-    pindexLast.nTime = 1262152739;  // Block #32255
+    pindexLast.nTime = 1262152739;  // Block #32255 of Bitcoin
     pindexLast.nBits = 0x1d00ffff;
     BOOST_CHECK_EQUAL(CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, params), 0x1d011998);
 }
@@ -33,10 +33,10 @@ BOOST_AUTO_TEST_CASE(get_next_work_pow_limit)
     SelectParams(CBaseChainParams::MAIN);
     const Consensus::Params& params = Params().GetConsensus();
 
-    int64_t nLastRetargetTime = 1231006505; // Block #0
+    int64_t nLastRetargetTime = 1231006505; // Block #0 of Bitcoin
     CBlockIndex pindexLast;
     pindexLast.nHeight = 2015;
-    pindexLast.nTime = 1233061996;  // Block #2015
+    pindexLast.nTime = 1233061996;  // Block #2015 of Bitcoin
     // TODO change once the harder genesis block is generated
     pindexLast.nBits = 0x207fffff;
     BOOST_CHECK_EQUAL(CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, params), 0x207fffff);
@@ -51,7 +51,7 @@ BOOST_AUTO_TEST_CASE(get_next_work_lower_limit_actual)
     int64_t nLastRetargetTime = 1279295950; // NOTE: Not an actual block time
     CBlockIndex pindexLast;
     pindexLast.nHeight = 68543;
-    pindexLast.nTime = 1279297671;  // Block #68543
+    pindexLast.nTime = 1279297671;  // Block #68543 of Bitcoin
     pindexLast.nBits = 0x1c05a3f4;
     BOOST_CHECK_EQUAL(CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, params), 0x1c05306f);
 }
@@ -65,7 +65,7 @@ BOOST_AUTO_TEST_CASE(get_next_work_upper_limit_actual)
     int64_t nLastRetargetTime = 1269207250; // NOTE: Not an actual block time
     CBlockIndex pindexLast;
     pindexLast.nHeight = 46367;
-    pindexLast.nTime = 1269211443;  // Block #46367
+    pindexLast.nTime = 1269211443;  // Block #46367 of Bitcoin
     pindexLast.nBits = 0x1c387f6f;
     BOOST_CHECK_EQUAL(CalculateNextWorkRequired(&pindexLast, nLastRetargetTime, params), 0x1c418995);
 }