From 2d2e5bdcf46d3b4b50d07edb2e010cf7e1cde1b1 Mon Sep 17 00:00:00 2001
From: Gregory Maxwell <greg@xiph.org>
Date: Wed, 24 Oct 2012 01:41:52 -0400
Subject: [PATCH] Fixes a race condition in CreateNewBlock.

CreateNewBlock was reading pindexBest at the start before taking the lock
so it was possible to have the the block content not match the prevheader.

(Partial of faff50d129b6d4b9e6397ac989218e83a26ae692)
---
 src/main.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/main.cpp b/src/main.cpp
index 26adbf71780..e740d8e3198 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3032,7 +3032,7 @@ public:
 
 CBlock* CreateNewBlock(CReserveKey& reservekey)
 {
-    CBlockIndex* pindexPrev = pindexBest;
+    CBlockIndex* pindexPrev;
 
     // Create new block
     auto_ptr<CBlock> pblock(new CBlock());
@@ -3054,6 +3054,7 @@ CBlock* CreateNewBlock(CReserveKey& reservekey)
     CRITICAL_BLOCK(cs_main)
     CRITICAL_BLOCK(cs_mapTransactions)
     {
+        pindexPrev = pindexBest;
         CTxDB txdb("r");
 
         // Priority order to process transactions