From 61a20cb56d5c135bc5525aa0089671da26572a78 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= <peterke@gmail.com>
Date: Thu, 18 Jul 2019 15:26:22 +0300
Subject: [PATCH] core: check error before accessing potentially nil block

---
 core/genesis.go | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/core/genesis.go b/core/genesis.go
index 57809fe73..87bab2520 100644
--- a/core/genesis.go
+++ b/core/genesis.go
@@ -164,7 +164,10 @@ func SetupGenesisBlock(db ethdb.Database, genesis *Genesis) (*params.ChainConfig
 			log.Info("Writing custom genesis block")
 		}
 		block, err := genesis.Commit(db)
-		return genesis.Config, block.Hash(), err
+		if err != nil {
+			return genesis.Config, common.Hash{}, err
+		}
+		return genesis.Config, block.Hash(), nil
 	}
 
 	// We have the genesis block in database(perhaps in ancient database)
@@ -180,7 +183,10 @@ func SetupGenesisBlock(db ethdb.Database, genesis *Genesis) (*params.ChainConfig
 			return genesis.Config, hash, &GenesisMismatchError{stored, hash}
 		}
 		block, err := genesis.Commit(db)
-		return genesis.Config, block.Hash(), err
+		if err != nil {
+			return genesis.Config, hash, err
+		}
+		return genesis.Config, block.Hash(), nil
 	}
 
 	// Check whether the genesis block is already written.