reenable rate limit on tx

src/core.h

@@ -215,7 +215,6 @@ public:
     }
 
     uint256 GetHash() const;
-    bool IsNewerThan(const CTransaction& old) const;
 
     bool IsSpamMessage() const
     {

src/main.cpp

@@ -923,8 +923,7 @@ bool CTxMemPool::accept(CValidationState &state, CTransaction &tx, bool fLimitFr
         // Continuously rate-limit free transactions
         // This mitigates 'penny-flooding' -- sending thousands of free transactions just to
         // be annoying or make others' transactions take longer to confirm.
-        /*
-        if (fLimitFree && nFees < CTransaction::nMinRelayTxFee)
+        if (fLimitFree)
         {
             static double dFreeCount;
             static int64 nLastTime;
@@ -943,7 +942,7 @@ bool CTxMemPool::accept(CValidationState &state, CTransaction &tx, bool fLimitFr
                 printf("Rate limit dFreeCount: %g => %g\n", dFreeCount, dFreeCount+nSize);
             dFreeCount += nSize;
         }
-        */
+
         // Check against previous transactions
         // This is done last to help prevent CPU exhaustion denial-of-service attacks.
         if (!CheckInputs(tx, state, view, true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_STRICTENC))