Improve debug logging, for mempool TXs that do not include sufficient fees

src/main.cpp

@@ -612,8 +612,11 @@ bool CTxMemPool::accept(CTxDB& txdb, CTransaction &tx, bool fCheckInputs,
         unsigned int nSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
 
         // Don't accept it if it can't get into a block
-        if (nFees < tx.GetMinFee(1000, true, GMF_RELAY))
-            return error("CTxMemPool::accept() : not enough fees");
+        int64 txMinFee = tx.GetMinFee(1000, true, GMF_RELAY);
+        if (nFees < txMinFee)
+            return error("CTxMemPool::accept() : not enough fees %s, %"PRI64d" < %"PRI64d,
+                         hash.ToString().substr(0,10).c_str(),
+                         nFees, txMinFee);
 
         // Continuously rate-limit free transactions
         // This mitigates 'penny-flooding' -- sending thousands of free transactions just to