From 3c40a9a667424a164522e17ec18d810d53d7677d Mon Sep 17 00:00:00 2001
From: Michael Toutonghi <michaeltoutonghi@gmail.com>
Date: Fri, 10 Aug 2018 17:21:41 -0700
Subject: [PATCH] Fail on get_chainactive before lock if checks fail

---
 src/miner.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/miner.cpp b/src/miner.cpp
index f31d6bd7c..908fd601f 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -813,11 +813,13 @@ int32_t waitForPeers(const CChainParams &chainparams)
 #ifdef ENABLE_WALLET
 CBlockIndex *get_chainactive(int32_t height)
 {
-    LOCK(cs_main);
-    if ( chainActive.Tip() != 0 )
+    if ( chainActive.LastTip() != 0 )
     {
-        if ( height <= chainActive.Tip()->nHeight )
+        if ( height <= chainActive.LastTip()->nHeight )
+        {
+            LOCK(cs_main);
             return(chainActive[height]);
+        }
         // else fprintf(stderr,"get_chainactive height %d > active.%d\n",height,chainActive.Tip()->nHeight);
     }
     //fprintf(stderr,"get_chainactive null chainActive.Tip() height %d\n",height);