2 files changed, 13 insertions, 3 deletions
diff --git a/src/consensus/consensus.h b/src/consensus/consensus.h
index 351911a3a4..58b2ed4b3e 100644
--- a/src/consensus/consensus.h
+++ b/src/consensus/consensus.h
@@ -12,7 +12,13 @@
 static const unsigned int MAX_BLOCK_SERIALIZED_SIZE = 4000000;
 /** The maximum allowed weight for a block, see BIP 141 (network rule) */
 static const unsigned int MAX_BLOCK_WEIGHT = 4000000;
-/** The maximum allowed size for a block excluding witness data, in bytes (network rule) */
+/**
+ * The maximum allowed size for a block excluding witness data, in bytes (network rule).
+ * This parameter is largely superfluous because it is directly implied by the above block
+ *  weight limit, even when BIP 141 is not active.  It continues to exist for use in
+ *  various early tests that run before the witness data has been checked.
+ * All tests related to it could be removed without breaking consensus compatibility.
+ */
 static const unsigned int MAX_BLOCK_BASE_SIZE = 1000000;
 /** The maximum allowed number of signature check operations in a block (network rule) */
 static const int64_t MAX_BLOCK_SIGOPS_COST = 80000;
diff --git a/src/consensus/tx_verify.cpp b/src/consensus/tx_verify.cpp
index bf68f8754b..0671cbc132 100644
--- a/src/consensus/tx_verify.cpp
+++ b/src/consensus/tx_verify.cpp
@@ -126,7 +126,9 @@ unsigned int GetP2SHSigOpCount(const CTransaction& tx, const CCoinsViewCache& in
     unsigned int nSigOps = 0;
     for (unsigned int i = 0; i < tx.vin.size(); i++)
     {
-        const CTxOut &prevout = inputs.AccessCoin(tx.vin[i].prevout).out;
+        const Coin& coin = inputs.AccessCoin(tx.vin[i].prevout);
+        assert(!coin.IsSpent());
+        const CTxOut &prevout = coin.out;
         if (prevout.scriptPubKey.IsPayToScriptHash())
             nSigOps += prevout.scriptPubKey.GetSigOpCount(tx.vin[i].scriptSig);
     }
@@ -146,7 +148,9 @@ int64_t GetTransactionSigOpCost(const CTransaction& tx, const CCoinsViewCache& i
 
     for (unsigned int i = 0; i < tx.vin.size(); i++)
     {
-        const CTxOut &prevout = inputs.AccessCoin(tx.vin[i].prevout).out;
+        const Coin& coin = inputs.AccessCoin(tx.vin[i].prevout);
+        assert(!coin.IsSpent());
+        const CTxOut &prevout = coin.out;
         nSigOps += CountWitnessSigOps(tx.vin[i].scriptSig, prevout.scriptPubKey, &tx.vin[i].scriptWitness, flags);
     }
     return nSigOps;