From 49b0efb36307a999699705e095a963526ed6bb0d Mon Sep 17 00:00:00 2001
From: wighawag <wighawag@gmail.com>
Date: Mon, 11 Sep 2017 11:42:38 +0100
Subject: [PATCH] eth : return an error when block specified is not present

---
 eth/api_backend.go | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/eth/api_backend.go b/eth/api_backend.go
index 91f392f94f..38534ee381 100644
--- a/eth/api_backend.go
+++ b/eth/api_backend.go
@@ -18,7 +18,9 @@ package eth
 
 import (
 	"context"
+	"errors"
 	"math/big"
+	"strconv"
 
 	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/common"
@@ -89,9 +91,13 @@ func (b *EthApiBackend) StateAndHeaderByNumber(ctx context.Context, blockNr rpc.
 	}
 	// Otherwise resolve the block number and return its state
 	header, err := b.HeaderByNumber(ctx, blockNr)
-	if header == nil || err != nil {
+	if err != nil {
 		return nil, nil, err
 	}
+	// If can't find specified block return an error
+	if header == nil {
+		return nil, nil, errors.New("block " + strconv.FormatInt(int64(blockNr), 10) + " not found")
+	}
 	stateDb, err := b.eth.BlockChain().StateAt(header.Root)
 	return stateDb, header, err
 }