Adding logging to investigate issue with very large eth_estimateGas v…

…alue (issue Consensys#461)

internal/ethapi/api.go

@@ -675,18 +675,21 @@ func (s *PublicBlockChainAPI) EstimateGas(ctx context.Context, args CallArgs) (*
 	)
 	if (*big.Int)(&args.Gas).Uint64() >= params.TxGas {
 		hi = (*big.Int)(&args.Gas).Uint64()
+		log.Info(fmt.Sprintf("======== estimateGas 1: hi = %v", hi))
 	} else {
 		// Retrieve the current pending block to act as the gas ceiling
 		block, err := s.b.BlockByNumber(ctx, rpc.PendingBlockNumber)
 		if err != nil {
 			return nil, err
 		}
 		hi = block.GasLimit().Uint64()
+		log.Info(fmt.Sprintf("======== estimateGas 2: hi = %v", hi))
 	}
 	for lo+1 < hi {
 		// Take a guess at the gas, and check transaction validity
 		mid := (hi + lo) / 2
 		(*big.Int)(&args.Gas).SetUint64(mid)
+		log.Info(fmt.Sprintf("======== estimateGas 3: mid = %v", mid))
 
 		_, _, failed, err := s.doCall(ctx, args, rpc.PendingBlockNumber, vm.Config{})
 
@@ -697,6 +700,7 @@ func (s *PublicBlockChainAPI) EstimateGas(ctx context.Context, args CallArgs) (*
 		}
 		// Otherwise assume the transaction succeeded, lower the gas limit
 		hi = mid
+		log.Info(fmt.Sprintf("======== estimateGas 4: set hi = %v", hi))
 	}
 	return (*hexutil.Big)(new(big.Int).SetUint64(hi)), nil
 }