From 0b297a614f80214dbd826fe5af92b4eaa60911bb Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter.wuille@gmail.com>
Date: Sun, 28 Oct 2012 19:14:51 +0100
Subject: [PATCH] Bugfix: don't crash by trying to write unchanged best block

---
 src/txdb.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/txdb.cpp b/src/txdb.cpp
index 67d15cb5..6550f578 100644
--- a/src/txdb.cpp
+++ b/src/txdb.cpp
@@ -58,7 +58,8 @@ bool CCoinsViewDB::BatchWrite(const std::map<uint256, CCoins> &mapCoins, CBlockI
     CLevelDBBatch batch;
     for (std::map<uint256, CCoins>::const_iterator it = mapCoins.begin(); it != mapCoins.end(); it++)
         BatchWriteCoins(batch, it->first, it->second);
-    BatchWriteHashBestChain(batch, pindex->GetBlockHash());
+    if (pindex)
+        BatchWriteHashBestChain(batch, pindex->GetBlockHash());
 
     return db.WriteBatch(batch);
 }