From 3a8029f0335dbdb039eccb7bddc88fb0cd1ff971 Mon Sep 17 00:00:00 2001
From: Luke Dashjr <luke-jr+git@utopios.org>
Date: Wed, 11 May 2011 16:50:14 -0400
Subject: [PATCH 1/3] Update nTime after nExtraNonce to avoid potential race
 (extraNonce being reset due to just-occurred time change after nTime is set)

---
 rpc.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/rpc.cpp b/rpc.cpp
index 90e7f15a9..2175dddb4 100644
--- a/rpc.cpp
+++ b/rpc.cpp
@@ -1330,15 +1330,15 @@ Value getwork(const Array& params, bool fHelp)
             vNewBlock.push_back(pblock);
         }
 
-        // Update nTime
-        pblock->nTime = max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
-        pblock->nNonce = 0;
-
         // Update nExtraNonce
         static unsigned int nExtraNonce = 0;
         static int64 nPrevTime = 0;
         IncrementExtraNonce(pblock, pindexPrev, nExtraNonce, nPrevTime);
 
+        // Update nTime
+        pblock->nTime = max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
+        pblock->nNonce = 0;
+
         // Save
         mapNewBlock[pblock->hashMerkleRoot] = make_pair(pblock, nExtraNonce);
 

From aa4a9c5250f94c82a9e4077a1b56ba634a9841fa Mon Sep 17 00:00:00 2001
From: Luke Dashjr <luke-jr+git@utopios.org>
Date: Wed, 11 May 2011 17:12:47 -0400
Subject: [PATCH 2/3] Reset extraNonce only every 15 seconds, just in case some
 miner is updating time himself and stuff

---
 main.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/main.cpp b/main.cpp
index 4c8f20c1e..bf7c99349 100644
--- a/main.cpp
+++ b/main.cpp
@@ -3448,7 +3448,7 @@ void IncrementExtraNonce(CBlock* pblock, CBlockIndex* pindexPrev, unsigned int&
 {
     // Update nExtraNonce
     int64 nNow = max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
-    if (++nExtraNonce >= 0x7f && nNow > nPrevTime+1)
+    if (++nExtraNonce >= 0x7f && nNow > nPrevTime+15)
     {
         nExtraNonce = 1;
         nPrevTime = nNow;

From 02d87b3aa375810bcd63dcf72637e788a75fc7d4 Mon Sep 17 00:00:00 2001
From: Luke Dashjr <luke-jr+git@utopios.org>
Date: Sun, 12 Jun 2011 20:16:54 -0400
Subject: [PATCH 3/3] Reset extraNonce only when prevBlock changes, so miners
 can continue updating the time on their work until it's stale

---
 main.cpp | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/main.cpp b/main.cpp
index bf7c99349..d71d41164 100644
--- a/main.cpp
+++ b/main.cpp
@@ -3447,12 +3447,13 @@ CBlock* CreateNewBlock(CReserveKey& reservekey)
 void IncrementExtraNonce(CBlock* pblock, CBlockIndex* pindexPrev, unsigned int& nExtraNonce, int64& nPrevTime)
 {
     // Update nExtraNonce
-    int64 nNow = max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
-    if (++nExtraNonce >= 0x7f && nNow > nPrevTime+15)
+    static uint256 hashPrevBlock;
+    if (hashPrevBlock != pblock->hashPrevBlock)
     {
-        nExtraNonce = 1;
-        nPrevTime = nNow;
+        nExtraNonce = 0;
+        hashPrevBlock = pblock->hashPrevBlock;
     }
+    ++nExtraNonce;
     pblock->vtx[0].vin[0].scriptSig = CScript() << pblock->nBits << CBigNum(nExtraNonce);
     pblock->hashMerkleRoot = pblock->BuildMerkleTree();
 }