X-Git-Url: https://git.novaco.in/?a=blobdiff_plain;f=src%2Fmain.cpp;h=01d99ebaf2c65efbd500e2b968722b43c008050b;hb=726b753c71c1ec24fd0f55a7badef4ef5a00769a;hp=2a633f6868c4021dbeab0d6ec348228e9eb18c39;hpb=5065be85c2dc1452e05c63d0017da0c096f68006;p=novacoin.git

diff --git a/src/main.cpp b/src/main.cpp
index 2a633f6..01d99eb 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,14 +1,16 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2012 The Bitcoin developers
-// Copyright (c) 2011-2012 The PPCoin developers
 // Distributed under the MIT/X11 software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include "alert.h"
 #include "checkpoints.h"
 #include "db.h"
 #include "net.h"
 #include "init.h"
 #include "ui_interface.h"
+#include "kernel.h"
+#include "scrypt_mine.h"
 #include <boost/algorithm/string/replace.hpp>
 #include <boost/filesystem.hpp>
 #include <boost/filesystem/fstream.hpp>
@@ -30,13 +32,24 @@ unsigned int nTransactionsUpdated = 0;
 
 map<uint256, CBlockIndex*> mapBlockIndex;
 set<pair<COutPoint, unsigned int> > setStakeSeen;
-uint256 hashGenesisBlock = hashGenesisBlockOfficial;
-static CBigNum bnProofOfWorkLimit(~uint256(0) >> 32);
-static CBigNum bnInitialHashTarget(~uint256(0) >> 40);
+
+CBigNum bnProofOfWorkLimit(~uint256(0) >> 20); // "standard" scrypt target limit for proof of work, results with 0,000244140625 proof-of-work difficulty
+CBigNum bnProofOfStakeLegacyLimit(~uint256(0) >> 24); // proof of stake target limit from block #15000 and until 20 June 2013, results with 0,00390625 proof of stake difficulty
+CBigNum bnProofOfStakeLimit(~uint256(0) >> 27); // proof of stake target limit since 20 June 2013, equal to 0.03125  proof of stake difficulty
+CBigNum bnProofOfStakeHardLimit(~uint256(0) >> 30); // disabled temporarily, will be used in the future to fix minimal proof of stake difficulty at 0.25
+
+CBigNum bnProofOfWorkLimitTestNet(~uint256(0) >> 16);
+
+unsigned int nStakeMinAge = 60 * 60 * 24 * 30; // 30 days as minimum age for coin age
+unsigned int nStakeMaxAge = 60 * 60 * 24 * 90; // 90 days as stake age of full weight
+unsigned int nStakeTargetSpacing = 10 * 60; // 10-minute stakes spacing
+unsigned int nModifierInterval = 6 * 60 * 60; // time to elapse before new modifier is computed
+
+int nCoinbaseMaturity = 500;
 CBlockIndex* pindexGenesisBlock = NULL;
 int nBestHeight = -1;
-uint64 nBestChainTrust = 0;
-uint64 nBestInvalidTrust = 0;
+CBigNum bnBestChainTrust = 0;
+CBigNum bnBestInvalidTrust = 0;
 uint256 hashBestChain = 0;
 CBlockIndex* pindexBest = NULL;
 int64 nTimeBestReceived = 0;
@@ -46,6 +59,7 @@ CMedianFilter<int> cPeerBlockCounts(5, 0); // Amount of blocks that other nodes
 map<uint256, CBlock*> mapOrphanBlocks;
 multimap<uint256, CBlock*> mapOrphanBlocksByPrev;
 set<pair<COutPoint, unsigned int> > setStakeSeenOrphan;
+map<uint256, uint256> mapProofOfStake;
 
 map<uint256, CDataStream*> mapOrphanTransactions;
 map<uint256, map<uint256, CDataStream*> > mapOrphanTransactionsByPrev;
@@ -53,7 +67,7 @@ map<uint256, map<uint256, CDataStream*> > mapOrphanTransactionsByPrev;
 // Constant stuff for coinbase transactions we create:
 CScript COINBASE_FLAGS;
 
-const string strMessageMagic = "PPCoin Signed Message:\n";
+const string strMessageMagic = "NovaCoin Signed Message:\n";
 
 double dHashesPerSec;
 int64 nHPSTimerStart;
@@ -62,7 +76,6 @@ int64 nHPSTimerStart;
 int64 nTransactionFee = MIN_TX_FEE;
 
 
-
 //////////////////////////////////////////////////////////////////////////////
 //
 // dispatching functions
@@ -113,7 +126,7 @@ void static EraseFromWallets(uint256 hash)
 }
 
 // make sure all wallets know about the given transaction, in the given block
-void static SyncWithWallets(const CTransaction& tx, const CBlock* pblock = NULL, bool fUpdate = false, bool fConnect = true)
+void SyncWithWallets(const CTransaction& tx, const CBlock* pblock, bool fUpdate, bool fConnect)
 {
     if (!fConnect)
     {
@@ -160,7 +173,7 @@ void static Inventory(const uint256& hash)
 }
 
 // ask wallets to resend their transactions
-void static ResendWalletTransactions()
+void ResendWalletTransactions()
 {
     BOOST_FOREACH(CWallet* pwallet, setpwalletRegistered)
         pwallet->ResendWalletTransactions();
@@ -196,7 +209,7 @@ bool AddOrphanTx(const CDataStream& vMsg)
     // at most 500 megabytes of orphans:
     if (pvMsg->size() > 5000)
     {
-        printf("ignoring large orphan tx (size: %u, hash: %s)\n", pvMsg->size(), hash.ToString().substr(0,10).c_str());
+        printf("ignoring large orphan tx (size: %"PRIszu", hash: %s)\n", pvMsg->size(), hash.ToString().substr(0,10).c_str());
         delete pvMsg;
         return false;
     }
@@ -205,7 +218,7 @@ bool AddOrphanTx(const CDataStream& vMsg)
     BOOST_FOREACH(const CTxIn& txin, tx.vin)
         mapOrphanTransactionsByPrev[txin.prevout.hash].insert(make_pair(hash, pvMsg));
 
-    printf("stored orphan tx %s (mapsz %u)\n", hash.ToString().substr(0,10).c_str(),
+    printf("stored orphan tx %s (mapsz %"PRIszu")\n", hash.ToString().substr(0,10).c_str(),
         mapOrphanTransactions.size());
     return true;
 }
@@ -284,6 +297,9 @@ bool CTransaction::ReadFromDisk(COutPoint prevout)
 
 bool CTransaction::IsStandard() const
 {
+    if (nVersion > CTransaction::CURRENT_VERSION)
+        return false;
+
     BOOST_FOREACH(const CTxIn& txin, vin)
     {
         // Biggest 'standard' txin is a 3-signature 3-of-3 CHECKMULTISIG
@@ -294,9 +310,12 @@ bool CTransaction::IsStandard() const
         if (!txin.scriptSig.IsPushOnly())
             return false;
     }
-    BOOST_FOREACH(const CTxOut& txout, vout)
+    BOOST_FOREACH(const CTxOut& txout, vout) {
         if (!::IsStandard(txout.scriptPubKey))
             return false;
+        if (txout.nValue == 0)
+            return false;
+    }
     return true;
 }
 
@@ -451,14 +470,18 @@ bool CTransaction::CheckTransaction() const
 
     // Check for negative or overflow output values
     int64 nValueOut = 0;
-    for (int i = 0; i < vout.size(); i++)
+    for (unsigned int i = 0; i < vout.size(); i++)
     {
         const CTxOut& txout = vout[i];
-        if (txout.IsEmpty() && (!IsCoinBase()) && (!IsCoinStake()))
+        if (txout.IsEmpty() && !IsCoinBase() && !IsCoinStake())
             return DoS(100, error("CTransaction::CheckTransaction() : txout empty for user transaction"));
-        // ppcoin: enforce minimum output amount
-        if ((!txout.IsEmpty()) && txout.nValue < MIN_TXOUT_AMOUNT)
+
+        // NovaCoin: enforce minimum output amount for user transactions
+        // (and for all transactions until 20 Sep 2013)
+        if ((!IsCoinBase() || nTime < CHAINCHECKS_SWITCH_TIME)
+                && (!txout.IsEmpty()) && txout.nValue < MIN_TXOUT_AMOUNT)
             return DoS(100, error("CTransaction::CheckTransaction() : txout.nValue below minimum"));
+
         if (txout.nValue > MAX_MONEY)
             return DoS(100, error("CTransaction::CheckTransaction() : txout.nValue too high"));
         nValueOut += txout.nValue;
@@ -478,7 +501,7 @@ bool CTransaction::CheckTransaction() const
     if (IsCoinBase())
     {
         if (vin[0].scriptSig.size() < 2 || vin[0].scriptSig.size() > 100)
-            return DoS(100, error("CTransaction::CheckTransaction() : coinbase script size"));
+            return DoS(100, error("CTransaction::CheckTransaction() : coinbase script size is invalid"));
     }
     else
     {
@@ -490,6 +513,38 @@ bool CTransaction::CheckTransaction() const
     return true;
 }
 
+int64 CTransaction::GetMinFee(unsigned int nBlockSize, bool fAllowFree,
+                              enum GetMinFee_mode mode) const
+{
+    // Base fee is either MIN_TX_FEE or MIN_RELAY_TX_FEE
+    int64 nBaseFee = (mode == GMF_RELAY) ? MIN_RELAY_TX_FEE : MIN_TX_FEE;
+
+    unsigned int nBytes = ::GetSerializeSize(*this, SER_NETWORK, PROTOCOL_VERSION);
+    unsigned int nNewBlockSize = nBlockSize + nBytes;
+    int64 nMinFee = (1 + (int64)nBytes / 1000) * nBaseFee;
+
+    // To limit dust spam, require MIN_TX_FEE/MIN_RELAY_TX_FEE if any output is less than 0.01
+    if (nMinFee < nBaseFee)
+    {
+        BOOST_FOREACH(const CTxOut& txout, vout)
+            if (txout.nValue < CENT)
+                nMinFee = nBaseFee;
+    }
+
+    // Raise the price as the block approaches full
+    if (nBlockSize != 1 && nNewBlockSize >= MAX_BLOCK_SIZE_GEN/2)
+    {
+        if (nNewBlockSize >= MAX_BLOCK_SIZE_GEN)
+            return MAX_MONEY;
+        nMinFee *= MAX_BLOCK_SIZE_GEN / (MAX_BLOCK_SIZE_GEN - nNewBlockSize);
+    }
+
+    if (!MoneyRange(nMinFee))
+        nMinFee = MAX_MONEY;
+    return nMinFee;
+}
+
+
 bool CTxMemPool::accept(CTxDB& txdb, CTransaction &tx, bool fCheckInputs,
                         bool* pfMissingInputs)
 {
@@ -502,6 +557,7 @@ bool CTxMemPool::accept(CTxDB& txdb, CTransaction &tx, bool fCheckInputs,
     // Coinbase is only valid in a block, not as a loose transaction
     if (tx.IsCoinBase())
         return tx.DoS(100, error("CTxMemPool::accept() : coinbase as individual tx"));
+
     // ppcoin: coinstake is also only valid in a block, not as a loose transaction
     if (tx.IsCoinStake())
         return tx.DoS(100, error("CTxMemPool::accept() : coinstake as individual tx"));
@@ -564,7 +620,7 @@ bool CTxMemPool::accept(CTxDB& txdb, CTransaction &tx, bool fCheckInputs,
                 return error("CTxMemPool::accept() : FetchInputs found invalid tx %s", hash.ToString().substr(0,10).c_str());
             if (pfMissingInputs)
                 *pfMissingInputs = true;
-            return error("CTxMemPool::accept() : FetchInputs failed %s", hash.ToString().substr(0,10).c_str());
+            return false;
         }
 
         // Check for non-standard pay-to-script-hash in inputs
@@ -579,12 +635,15 @@ bool CTxMemPool::accept(CTxDB& txdb, CTransaction &tx, bool fCheckInputs,
         unsigned int nSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
 
         // Don't accept it if it can't get into a block
-        if (nFees < tx.GetMinFee(1000, false, GMF_RELAY))
-            return error("CTxMemPool::accept() : not enough fees");
+        int64 txMinFee = tx.GetMinFee(1000, false, GMF_RELAY);
+        if (nFees < txMinFee)
+            return error("CTxMemPool::accept() : not enough fees %s, %"PRI64d" < %"PRI64d,
+                         hash.ToString().c_str(),
+                         nFees, txMinFee);
 
         // Continuously rate-limit free transactions
         // This mitigates 'penny-flooding' -- sending thousands of free transactions just to
-        // be annoying or make other's transactions take longer to confirm.
+        // be annoying or make others' transactions take longer to confirm.
         if (nFees < MIN_RELAY_TX_FEE)
         {
             static CCriticalSection cs;
@@ -623,7 +682,7 @@ bool CTxMemPool::accept(CTxDB& txdb, CTransaction &tx, bool fCheckInputs,
             printf("CTxMemPool::accept() : replacing tx %s with new version\n", ptxOld->GetHash().ToString().c_str());
             remove(*ptxOld);
         }
-        addUnchecked(tx);
+        addUnchecked(hash, tx);
     }
 
     ///// are we sure this is ok when loading transactions or restoring block txes
@@ -631,7 +690,9 @@ bool CTxMemPool::accept(CTxDB& txdb, CTransaction &tx, bool fCheckInputs,
     if (ptxOld)
         EraseFromWallets(ptxOld->GetHash());
 
-    printf("CTxMemPool::accept() : accepted %s\n", hash.ToString().substr(0,10).c_str());
+    printf("CTxMemPool::accept() : accepted %s (poolsz %"PRIszu")\n",
+           hash.ToString().substr(0,10).c_str(),
+           mapTx.size());
     return true;
 }
 
@@ -640,14 +701,11 @@ bool CTransaction::AcceptToMemoryPool(CTxDB& txdb, bool fCheckInputs, bool* pfMi
     return mempool.accept(txdb, *this, fCheckInputs, pfMissingInputs);
 }
 
-bool CTxMemPool::addUnchecked(CTransaction &tx)
+bool CTxMemPool::addUnchecked(const uint256& hash, CTransaction &tx)
 {
-    printf("addUnchecked(): size %lu\n",  mapTx.size());
     // Add to memory pool without checking anything.  Don't call this directly,
     // call CTxMemPool::accept to properly check the transaction first.
     {
-        LOCK(cs);
-        uint256 hash = tx.GetHash();
         mapTx[hash] = tx;
         for (unsigned int i = 0; i < tx.vin.size(); i++)
             mapNextTx[tx.vin[i].prevout] = CInPoint(&mapTx[hash], i);
@@ -674,7 +732,23 @@ bool CTxMemPool::remove(CTransaction &tx)
     return true;
 }
 
+void CTxMemPool::clear()
+{
+    LOCK(cs);
+    mapTx.clear();
+    mapNextTx.clear();
+    ++nTransactionsUpdated;
+}
+
+void CTxMemPool::queryHashes(std::vector<uint256>& vtxid)
+{
+    vtxid.clear();
 
+    LOCK(cs);
+    vtxid.reserve(mapTx.size());
+    for (map<uint256, CTransaction>::iterator mi = mapTx.begin(); mi != mapTx.end(); ++mi)
+        vtxid.push_back((*mi).first);
+}
 
 
 
@@ -709,7 +783,7 @@ int CMerkleTx::GetBlocksToMaturity() const
 {
     if (!(IsCoinBase() || IsCoinStake()))
         return 0;
-    return max(0, (COINBASE_MATURITY+20) - GetDepthInMainChain());
+    return max(0, (nCoinbaseMaturity+20) - GetDepthInMainChain());
 }
 
 
@@ -777,7 +851,31 @@ int CTxIndex::GetDepthInMainChain() const
     return 1 + nBestHeight - pindex->nHeight;
 }
 
-
+// Return transaction in tx, and if it was found inside a block, its hash is placed in hashBlock
+bool GetTransaction(const uint256 &hash, CTransaction &tx, uint256 &hashBlock)
+{
+    {
+        LOCK(cs_main);
+        {
+            LOCK(mempool.cs);
+            if (mempool.exists(hash))
+            {
+                tx = mempool.lookup(hash);
+                return true;
+            }
+        }
+        CTxDB txdb("r");
+        CTxIndex txindex;
+        if (tx.ReadFromDisk(txdb, COutPoint(hash, 0), txindex))
+        {
+            CBlock block;
+            if (block.ReadFromDisk(txindex.pos.nFile, txindex.pos.nBlockPos, false))
+                hashBlock = block.GetHash();
+            return true;
+        }
+    }
+    return false;
+}
 
 
 
@@ -791,6 +889,24 @@ int CTxIndex::GetDepthInMainChain() const
 // CBlock and CBlockIndex
 //
 
+static CBlockIndex* pblockindexFBBHLast;
+CBlockIndex* FindBlockByHeight(int nHeight)
+{
+    CBlockIndex *pblockindex;
+    if (nHeight < nBestHeight / 2)
+        pblockindex = pindexGenesisBlock;
+    else
+        pblockindex = pindexBest;
+    if (pblockindexFBBHLast && abs(nHeight - pblockindex->nHeight) > abs(nHeight - pblockindexFBBHLast->nHeight))
+        pblockindex = pblockindexFBBHLast;
+    while (pblockindex->nHeight > nHeight)
+        pblockindex = pblockindex->pprev;
+    while (pblockindex->nHeight < nHeight)
+        pblockindex = pblockindex->pnext;
+    pblockindexFBBHLast = pblockindex;
+    return pblockindex;
+}
+
 bool CBlock::ReadFromDisk(const CBlockIndex* pindex, bool fReadTransactions)
 {
     if (!fReadTransactions)
@@ -822,17 +938,38 @@ uint256 WantedByOrphan(const CBlock* pblockOrphan)
     return pblockOrphan->hashPrevBlock;
 }
 
-int64 static GetProofOfWorkReward(unsigned int nBits)
+// select stake target limit according to hard-coded conditions
+CBigNum static GetProofOfStakeLimit(int nHeight, unsigned int nTime)
+{
+    if(fTestNet) // separate proof of stake target limit for testnet
+        return bnProofOfStakeLimit;
+    if(nTime > TARGETS_SWITCH_TIME) // 27 bits since 20 July 2013
+        return bnProofOfStakeLimit;
+    if(nHeight + 1 > 15000) // 24 bits since block 15000
+        return bnProofOfStakeLegacyLimit;
+    if(nHeight + 1 > 14060) // 31 bits since block 14060 until 15000
+        return bnProofOfStakeHardLimit;
+
+    return bnProofOfWorkLimit; // return bnProofOfWorkLimit of none matched
+}
+
+// miner's coin base reward based on nBits
+int64 GetProofOfWorkReward(unsigned int nBits)
 {
     CBigNum bnSubsidyLimit = MAX_MINT_PROOF_OF_WORK;
+
     CBigNum bnTarget;
     bnTarget.SetCompact(nBits);
     CBigNum bnTargetLimit = bnProofOfWorkLimit;
     bnTargetLimit.SetCompact(bnTargetLimit.GetCompact());
 
-    // ppcoin: subsidy is cut in half every 16x multiply of difficulty
+    // NovaCoin: subsidy is cut in half every 64x multiply of PoW difficulty
     // A reasonably continuous curve is used to avoid shock to market
-    // (nSubsidyLimit / nSubsidy) ** 4 == bnProofOfWorkLimit / bnTarget
+    // (nSubsidyLimit / nSubsidy) ** 6 == bnProofOfWorkLimit / bnTarget
+    //
+    // Human readable form:
+    //
+    // nSubsidy = 100 / (diff ^ 1/6)
     CBigNum bnLowerBound = CENT;
     CBigNum bnUpperBound = bnSubsidyLimit;
     while (bnLowerBound + CENT <= bnUpperBound)
@@ -840,13 +977,14 @@ int64 static GetProofOfWorkReward(unsigned int nBits)
         CBigNum bnMidValue = (bnLowerBound + bnUpperBound) / 2;
         if (fDebug && GetBoolArg("-printcreation"))
             printf("GetProofOfWorkReward() : lower=%"PRI64d" upper=%"PRI64d" mid=%"PRI64d"\n", bnLowerBound.getuint64(), bnUpperBound.getuint64(), bnMidValue.getuint64());
-        if (bnMidValue * bnMidValue * bnMidValue * bnMidValue * bnTargetLimit > bnSubsidyLimit * bnSubsidyLimit * bnSubsidyLimit * bnSubsidyLimit * bnTarget)
+        if (bnMidValue * bnMidValue * bnMidValue * bnMidValue * bnMidValue * bnMidValue * bnTargetLimit > bnSubsidyLimit * bnSubsidyLimit * bnSubsidyLimit * bnSubsidyLimit * bnSubsidyLimit * bnSubsidyLimit * bnTarget)
             bnUpperBound = bnMidValue;
         else
             bnLowerBound = bnMidValue;
     }
 
     int64 nSubsidy = bnUpperBound.getuint64();
+
     nSubsidy = (nSubsidy / CENT) * CENT;
     if (fDebug && GetBoolArg("-printcreation"))
         printf("GetProofOfWorkReward() : create=%s nBits=0x%08x nSubsidy=%"PRI64d"\n", FormatMoney(nSubsidy).c_str(), nBits, nSubsidy);
@@ -854,20 +992,70 @@ int64 static GetProofOfWorkReward(unsigned int nBits)
     return min(nSubsidy, MAX_MINT_PROOF_OF_WORK);
 }
 
-// ppcoin: miner's coin stake is rewarded based on coin age spent (coin-days)
-int64 GetProofOfStakeReward(int64 nCoinAge)
+// miner's coin stake reward based on nBits and coin age spent (coin-days)
+int64 GetProofOfStakeReward(int64 nCoinAge, unsigned int nBits, unsigned int nTime)
 {
-    static int64 nRewardCoinYear = CENT;  // creation amount per coin-year
+    int64 nRewardCoinYear;
+
+    if(fTestNet || nTime > STAKE_SWITCH_TIME)
+    {
+        // Stage 2 of emission process is PoS-based. It will be active on mainNet since 20 Jun 2013.
+
+        CBigNum bnRewardCoinYearLimit = MAX_MINT_PROOF_OF_STAKE; // Base stake mint rate, 100% year interest
+        CBigNum bnTarget;
+        bnTarget.SetCompact(nBits);
+        CBigNum bnTargetLimit = GetProofOfStakeLimit(0, nTime);
+        bnTargetLimit.SetCompact(bnTargetLimit.GetCompact());
+
+        // NovaCoin: reward for coin-year is cut in half every 64x multiply of PoS difficulty
+        // A reasonably continuous curve is used to avoid shock to market
+        // (nRewardCoinYearLimit / nRewardCoinYear) ** 6 == bnProofOfStakeLimit / bnTarget
+        //
+        // Human readable form:
+        //
+        // nRewardCoinYear = 1 / (posdiff ^ 1/6)
+
+        CBigNum bnLowerBound = 1 * CENT; // Lower interest bound is 1% per year
+        CBigNum bnUpperBound = bnRewardCoinYearLimit;
+        while (bnLowerBound + CENT <= bnUpperBound)
+        {
+            CBigNum bnMidValue = (bnLowerBound + bnUpperBound) / 2;
+            if (fDebug && GetBoolArg("-printcreation"))
+                printf("GetProofOfStakeReward() : lower=%"PRI64d" upper=%"PRI64d" mid=%"PRI64d"\n", bnLowerBound.getuint64(), bnUpperBound.getuint64(), bnMidValue.getuint64());
+            if (bnMidValue * bnMidValue * bnMidValue * bnMidValue * bnMidValue * bnMidValue * bnTargetLimit > bnRewardCoinYearLimit * bnRewardCoinYearLimit * bnRewardCoinYearLimit * bnRewardCoinYearLimit * bnRewardCoinYearLimit * bnRewardCoinYearLimit * bnTarget)
+                bnUpperBound = bnMidValue;
+            else
+                bnLowerBound = bnMidValue;
+        }
+
+        nRewardCoinYear = bnUpperBound.getuint64();
+        nRewardCoinYear = min((nRewardCoinYear / CENT) * CENT, MAX_MINT_PROOF_OF_STAKE);
+    }
+    else
+    {
+        // Old creation amount per coin-year, 5% fixed stake mint rate
+        nRewardCoinYear = 5 * CENT;
+    }
+
     int64 nSubsidy = nCoinAge * 33 / (365 * 33 + 8) * nRewardCoinYear;
     if (fDebug && GetBoolArg("-printcreation"))
-        printf("GetProofOfStakeReward(): create=%s nCoinAge=%"PRI64d"\n", FormatMoney(nSubsidy).c_str(), nCoinAge);
+        printf("GetProofOfStakeReward(): create=%s nCoinAge=%"PRI64d" nBits=%d\n", FormatMoney(nSubsidy).c_str(), nCoinAge, nBits);
     return nSubsidy;
 }
 
 static const int64 nTargetTimespan = 7 * 24 * 60 * 60;  // one week
-static const int64 nTargetSpacingStake = 10 * 60;       // ten minutes
-static const int64 nTargetSpacingWorkMax = 2 * 60 * 60; // two hours
-static const int64 nMaxClockDrift = 2 * 60 * 60;        // two hours
+
+// get proof of work blocks max spacing according to hard-coded conditions
+int64 static GetTargetSpacingWorkMax(int nHeight, unsigned int nTime)
+{
+    if(nTime > TARGETS_SWITCH_TIME)
+        return 3 * nStakeTargetSpacing; // 30 minutes on mainNet since 20 Jul 2013 00:00:00
+
+    if(fTestNet)
+        return 3 * nStakeTargetSpacing; // 15 minutes on testNet
+
+    return 12 * nStakeTargetSpacing; // 2 hours otherwise
+}
 
 //
 // minimum amount of work that could possibly be required nTime after
@@ -875,17 +1063,19 @@ static const int64 nMaxClockDrift = 2 * 60 * 60;        // two hours
 //
 unsigned int ComputeMinWork(unsigned int nBase, int64 nTime)
 {
+    CBigNum bnTargetLimit = bnProofOfWorkLimit;
+
     CBigNum bnResult;
     bnResult.SetCompact(nBase);
     bnResult *= 2;
-    while (nTime > 0 && bnResult < bnProofOfWorkLimit)
+    while (nTime > 0 && bnResult < bnTargetLimit)
     {
         // Maximum 200% adjustment per day...
         bnResult *= 2;
         nTime -= 24 * 60 * 60;
     }
-    if (bnResult > bnProofOfWorkLimit)
-        bnResult = bnProofOfWorkLimit;
+    if (bnResult > bnTargetLimit)
+        bnResult = bnTargetLimit;
     return bnResult.GetCompact();
 }
 
@@ -897,17 +1087,19 @@ const CBlockIndex* GetLastBlockIndex(const CBlockIndex* pindex, bool fProofOfSta
     return pindex;
 }
 
-unsigned int static GetNextTargetRequired(const CBlockIndex* pindexLast, bool fProofOfStake)
+unsigned int GetNextTargetRequired(const CBlockIndex* pindexLast, bool fProofOfStake)
 {
+    CBigNum bnTargetLimit = !fProofOfStake ? bnProofOfWorkLimit : GetProofOfStakeLimit(pindexLast->nHeight, pindexLast->nTime);
+
     if (pindexLast == NULL)
-        return bnProofOfWorkLimit.GetCompact(); // genesis block
+        return bnTargetLimit.GetCompact(); // genesis block
 
     const CBlockIndex* pindexPrev = GetLastBlockIndex(pindexLast, fProofOfStake);
     if (pindexPrev->pprev == NULL)
-        return bnInitialHashTarget.GetCompact(); // first block
+        return bnTargetLimit.GetCompact(); // first block
     const CBlockIndex* pindexPrevPrev = GetLastBlockIndex(pindexPrev->pprev, fProofOfStake);
     if (pindexPrevPrev->pprev == NULL)
-        return bnInitialHashTarget.GetCompact(); // second block
+        return bnTargetLimit.GetCompact(); // second block
 
     int64 nActualSpacing = pindexPrev->GetBlockTime() - pindexPrevPrev->GetBlockTime();
 
@@ -915,13 +1107,13 @@ unsigned int static GetNextTargetRequired(const CBlockIndex* pindexLast, bool fP
     // ppcoin: retarget with exponential moving toward target spacing
     CBigNum bnNew;
     bnNew.SetCompact(pindexPrev->nBits);
-    int64 nTargetSpacing = fProofOfStake? nTargetSpacingStake : min(nTargetSpacingWorkMax, nTargetSpacingStake * (1 + pindexLast->nHeight - pindexPrev->nHeight));
+    int64 nTargetSpacing = fProofOfStake? nStakeTargetSpacing : min(GetTargetSpacingWorkMax(pindexLast->nHeight, pindexLast->nTime), (int64) nStakeTargetSpacing * (1 + pindexLast->nHeight - pindexPrev->nHeight));
     int64 nInterval = nTargetTimespan / nTargetSpacing;
     bnNew *= ((nInterval - 1) * nTargetSpacing + nActualSpacing + nActualSpacing);
     bnNew /= ((nInterval + 1) * nTargetSpacing);
 
-    if (bnNew > bnProofOfWorkLimit)
-        bnNew = bnProofOfWorkLimit;
+    if (bnNew > bnTargetLimit)
+        bnNew = bnTargetLimit;
 
     return bnNew.GetCompact();
 }
@@ -965,17 +1157,28 @@ bool IsInitialBlockDownload()
 
 void static InvalidChainFound(CBlockIndex* pindexNew)
 {
-    if (pindexNew->nChainTrust > nBestInvalidTrust)
+    if (pindexNew->bnChainTrust > bnBestInvalidTrust)
     {
-        nBestInvalidTrust = pindexNew->nChainTrust;
-        CTxDB().WriteBestInvalidTrust(nBestInvalidTrust);
-        MainFrameRepaint();
+        bnBestInvalidTrust = pindexNew->bnChainTrust;
+        CTxDB().WriteBestInvalidTrust(bnBestInvalidTrust);
+        uiInterface.NotifyBlocksChanged();
     }
-    printf("InvalidChainFound: invalid block=%s  height=%d  trust=%s\n", pindexNew->GetBlockHash().ToString().substr(0,20).c_str(), pindexNew->nHeight, CBigNum(pindexNew->nChainTrust).ToString().c_str());
-    printf("InvalidChainFound:  current best=%s  height=%d  trust=%s\n", hashBestChain.ToString().substr(0,20).c_str(), nBestHeight, CBigNum(nBestChainTrust).ToString().c_str());
-    // ppcoin: should not enter safe mode for longer invalid chain
+
+    CBigNum bnBestInvalidBlockTrust = pindexNew->bnChainTrust - pindexNew->pprev->bnChainTrust;
+    CBigNum bnBestBlockTrust = pindexBest->nHeight != 0 ? (pindexBest->bnChainTrust - pindexBest->pprev->bnChainTrust) : pindexBest->bnChainTrust;
+
+    printf("InvalidChainFound: invalid block=%s  height=%d  trust=%s  blocktrust=%s  date=%s\n",
+      pindexNew->GetBlockHash().ToString().substr(0,20).c_str(), pindexNew->nHeight,
+      pindexNew->bnChainTrust.ToString().c_str(), bnBestInvalidBlockTrust.ToString().c_str(),
+      DateTimeStrFormat("%x %H:%M:%S", pindexNew->GetBlockTime()).c_str());
+    printf("InvalidChainFound:  current best=%s  height=%d  trust=%s  blocktrust=%s  date=%s\n",
+      hashBestChain.ToString().substr(0,20).c_str(), nBestHeight, 
+      bnBestChainTrust.ToString().c_str(),
+      bnBestBlockTrust.ToString().c_str(),
+      DateTimeStrFormat("%x %H:%M:%S", pindexBest->GetBlockTime()).c_str());
 }
 
+
 void CBlock::UpdateTime(const CBlockIndex* pindexPrev)
 {
     nTime = max(GetBlockTime(), GetAdjustedTime());
@@ -1020,7 +1223,7 @@ bool CTransaction::DisconnectInputs(CTxDB& txdb)
     // Remove transaction from index
     // This can fail if a duplicate of this transaction was in a chain that got
     // reorganized away. This is only possible if this transaction was completely
-    // spent, so erasing it would be a no-op anway.
+    // spent, so erasing it would be a no-op anyway.
     txdb.EraseTxIndex(*this);
 
     return true;
@@ -1083,7 +1286,7 @@ bool CTransaction::FetchInputs(CTxDB& txdb, const map<uint256, CTxIndex>& mapTes
         }
     }
 
-    // Make sure all prevout.n's are valid:
+    // Make sure all prevout.n indexes are valid:
     for (unsigned int i = 0; i < vin.size(); i++)
     {
         const COutPoint prevout = vin[i].prevout;
@@ -1095,7 +1298,7 @@ bool CTransaction::FetchInputs(CTxDB& txdb, const map<uint256, CTxIndex>& mapTes
             // Revisit this if/when transaction replacement is implemented and allows
             // adding inputs:
             fInvalid = true;
-            return DoS(100, error("FetchInputs() : %s prevout.n out of range %d %d %d prev tx %s\n%s", GetHash().ToString().substr(0,10).c_str(), prevout.n, txPrev.vout.size(), txindex.vSpent.size(), prevout.hash.ToString().substr(0,10).c_str(), txPrev.ToString().c_str()));
+            return DoS(100, error("FetchInputs() : %s prevout.n out of range %d %"PRIszu" %"PRIszu" prev tx %s\n%s", GetHash().ToString().substr(0,10).c_str(), prevout.n, txPrev.vout.size(), txindex.vSpent.size(), prevout.hash.ToString().substr(0,10).c_str(), txPrev.ToString().c_str()));
         }
     }
 
@@ -1164,13 +1367,13 @@ bool CTransaction::ConnectInputs(CTxDB& txdb, MapPrevTx inputs,
             CTransaction& txPrev = inputs[prevout.hash].second;
 
             if (prevout.n >= txPrev.vout.size() || prevout.n >= txindex.vSpent.size())
-                return DoS(100, error("ConnectInputs() : %s prevout.n out of range %d %d %d prev tx %s\n%s", GetHash().ToString().substr(0,10).c_str(), prevout.n, txPrev.vout.size(), txindex.vSpent.size(), prevout.hash.ToString().substr(0,10).c_str(), txPrev.ToString().c_str()));
+                return DoS(100, error("ConnectInputs() : %s prevout.n out of range %d %"PRIszu" %"PRIszu" prev tx %s\n%s", GetHash().ToString().substr(0,10).c_str(), prevout.n, txPrev.vout.size(), txindex.vSpent.size(), prevout.hash.ToString().substr(0,10).c_str(), txPrev.ToString().c_str()));
 
-            // If prev is coinbase/coinstake, check that it's matured
+            // If prev is coinbase or coinstake, check that it's matured
             if (txPrev.IsCoinBase() || txPrev.IsCoinStake())
-                for (const CBlockIndex* pindex = pindexBlock; pindex && pindexBlock->nHeight - pindex->nHeight < COINBASE_MATURITY; pindex = pindex->pprev)
+                for (const CBlockIndex* pindex = pindexBlock; pindex && pindexBlock->nHeight - pindex->nHeight < nCoinbaseMaturity; pindex = pindex->pprev)
                     if (pindex->nBlockPos == txindex.pos.nBlockPos && pindex->nFile == txindex.pos.nFile)
-                        return error("ConnectInputs() : tried to spend coinbase/coinstake at depth %d", pindexBlock->nHeight - pindex->nHeight);
+                        return error("ConnectInputs() : tried to spend %s at depth %d", txPrev.IsCoinBase() ? "coinbase" : "coinstake", pindexBlock->nHeight - pindex->nHeight);
 
             // ppcoin: check transaction timestamp
             if (txPrev.nTime > nTime)
@@ -1232,7 +1435,7 @@ bool CTransaction::ConnectInputs(CTxDB& txdb, MapPrevTx inputs,
             if (!GetCoinAge(txdb, nCoinAge))
                 return error("ConnectInputs() : %s unable to get coin age for coinstake", GetHash().ToString().substr(0,10).c_str());
             int64 nStakeReward = GetValueOut() - nValueIn;
-            if (nStakeReward > GetProofOfStakeReward(nCoinAge))
+            if (nStakeReward > GetProofOfStakeReward(nCoinAge, pindexBlock->nBits, nTime) - GetMinFee() + MIN_TX_FEE)
                 return DoS(100, error("ConnectInputs() : %s stake reward exceeded", GetHash().ToString().substr(0,10).c_str()));
         }
         else
@@ -1247,6 +1450,7 @@ bool CTransaction::ConnectInputs(CTxDB& txdb, MapPrevTx inputs,
             // ppcoin: enforce transaction fees for every block
             if (nTxFee < GetMinFee())
                 return fBlock? DoS(100, error("ConnectInputs() : %s not paying required fee=%s, paid=%s", GetHash().ToString().substr(0,10).c_str(), FormatMoney(GetMinFee()).c_str(), FormatMoney(nTxFee).c_str())) : false;
+
             nFees += nTxFee;
             if (!MoneyRange(nFees))
                 return DoS(100, error("ConnectInputs() : nFees out of range"));
@@ -1330,10 +1534,10 @@ bool CBlock::DisconnectBlock(CTxDB& txdb, CBlockIndex* pindex)
     return true;
 }
 
-bool CBlock::ConnectBlock(CTxDB& txdb, CBlockIndex* pindex)
+bool CBlock::ConnectBlock(CTxDB& txdb, CBlockIndex* pindex, bool fJustCheck)
 {
     // Check it again in case a previous version let a bad block in
-    if (!CheckBlock())
+    if (!CheckBlock(!fJustCheck, !fJustCheck))
         return false;
 
     // Do not allow blocks that contain transactions which 'overwrite' older transactions,
@@ -1343,44 +1547,53 @@ bool CBlock::ConnectBlock(CTxDB& txdb, CBlockIndex* pindex)
     // being sent to another address.
     // See BIP30 and http://r6.ca/blog/20120206T005236Z.html for more information.
     // This logic is not necessary for memory pool transactions, as AcceptToMemoryPool
-    // already refuses previously-known transaction id's entirely.
-    // This rule applies to all blocks whose timestamp is after March 15, 2012, 0:00 UTC.
-    // On testnet it is enabled as of februari 20, 2012, 0:00 UTC.
-    if (pindex->nTime > 1331769600 || (fTestNet && pindex->nTime > 1329696000))
-    {
-        BOOST_FOREACH(CTransaction& tx, vtx)
-        {
-            CTxIndex txindexOld;
-            if (txdb.ReadTxIndex(tx.GetHash(), txindexOld))
-            {
-                BOOST_FOREACH(CDiskTxPos &pos, txindexOld.vSpent)
-                    if (pos.IsNull())
-                        return false;
-            }
-        }
-    }
-
-    // BIP16 didn't become active until Apr 1 2012 (Feb 15 on testnet)
-    int64 nBIP16SwitchTime = fTestNet ? 1329264000 : 1333238400;
-    bool fStrictPayToScriptHash = (pindex->nTime >= nBIP16SwitchTime);
+    // already refuses previously-known transaction ids entirely.
+    // This rule was originally applied all blocks whose timestamp was after March 15, 2012, 0:00 UTC.
+    // Now that the whole chain is irreversibly beyond that time it is applied to all blocks except the
+    // two in the chain that violate it. This prevents exploiting the issue against nodes in their
+    // initial block download.
+    bool fEnforceBIP30 = true; // Always active in NovaCoin
+    bool fStrictPayToScriptHash = true; // Always active in NovaCoin
 
     //// issue here: it doesn't know the version
-    unsigned int nTxPos = pindex->nBlockPos + ::GetSerializeSize(CBlock(), SER_DISK, CLIENT_VERSION) - (2 * GetSizeOfCompactSize(0)) + GetSizeOfCompactSize(vtx.size());
+    unsigned int nTxPos;
+    if (fJustCheck)
+        // FetchInputs treats CDiskTxPos(1,1,1) as a special "refer to memorypool" indicator
+        // Since we're just checking the block and not actually connecting it, it might not (and probably shouldn't) be on the disk to get the transaction from
+        nTxPos = 1;
+    else
+        nTxPos = pindex->nBlockPos + ::GetSerializeSize(CBlock(), SER_DISK, CLIENT_VERSION) - (2 * GetSizeOfCompactSize(0)) + GetSizeOfCompactSize(vtx.size());
 
     map<uint256, CTxIndex> mapQueuedChanges;
     int64 nFees = 0;
+    int64 nValueIn = 0;
+    int64 nValueOut = 0;
     unsigned int nSigOps = 0;
     BOOST_FOREACH(CTransaction& tx, vtx)
     {
+        uint256 hashTx = tx.GetHash();
+
+        if (fEnforceBIP30) {
+            CTxIndex txindexOld;
+            if (txdb.ReadTxIndex(hashTx, txindexOld)) {
+                BOOST_FOREACH(CDiskTxPos &pos, txindexOld.vSpent)
+                    if (pos.IsNull())
+                        return false;
+            }
+        }
+
         nSigOps += tx.GetLegacySigOpCount();
         if (nSigOps > MAX_BLOCK_SIGOPS)
             return DoS(100, error("ConnectBlock() : too many sigops"));
 
         CDiskTxPos posThisTx(pindex->nFile, pindex->nBlockPos, nTxPos);
-        nTxPos += ::GetSerializeSize(tx, SER_DISK, CLIENT_VERSION);
+        if (!fJustCheck)
+            nTxPos += ::GetSerializeSize(tx, SER_DISK, CLIENT_VERSION);
 
         MapPrevTx mapInputs;
-        if (!tx.IsCoinBase())
+        if (tx.IsCoinBase())
+            nValueOut += tx.GetValueOut();
+        else
         {
             bool fInvalid;
             if (!tx.FetchInputs(txdb, mapQueuedChanges, true, false, mapInputs, fInvalid))
@@ -1396,16 +1609,34 @@ bool CBlock::ConnectBlock(CTxDB& txdb, CBlockIndex* pindex)
                     return DoS(100, error("ConnectBlock() : too many sigops"));
             }
 
+            int64 nTxValueIn = tx.GetValueIn(mapInputs);
+            int64 nTxValueOut = tx.GetValueOut();
+            nValueIn += nTxValueIn;
+            nValueOut += nTxValueOut;
             if (!tx.IsCoinStake())
-                nFees += tx.GetValueIn(mapInputs)-tx.GetValueOut();
+                nFees += nTxValueIn - nTxValueOut;
 
             if (!tx.ConnectInputs(txdb, mapInputs, mapQueuedChanges, posThisTx, pindex, true, false, fStrictPayToScriptHash))
                 return false;
         }
 
-        mapQueuedChanges[tx.GetHash()] = CTxIndex(posThisTx, tx.vout.size());
+        mapQueuedChanges[hashTx] = CTxIndex(posThisTx, tx.vout.size());
     }
 
+    // ppcoin: track money supply and mint amount info
+    pindex->nMint = nValueOut - nValueIn + nFees;
+    pindex->nMoneySupply = (pindex->pprev? pindex->pprev->nMoneySupply : 0) + nValueOut - nValueIn;
+    if (!txdb.WriteBlockIndex(CDiskBlockIndex(pindex)))
+        return error("Connect() : WriteBlockIndex for pindex failed");
+
+    // ppcoin: fees are not collected by miners as in bitcoin
+    // ppcoin: fees are destroyed to compensate the entire network
+    if (fDebug && GetBoolArg("-printcreation"))
+        printf("ConnectBlock() : destroy=%s nFees=%"PRI64d"\n", FormatMoney(nFees).c_str(), nFees);
+
+    if (fJustCheck)
+        return true;
+
     // Write queued txindex changes
     for (map<uint256, CTxIndex>::iterator mi = mapQueuedChanges.begin(); mi != mapQueuedChanges.end(); ++mi)
     {
@@ -1413,13 +1644,6 @@ bool CBlock::ConnectBlock(CTxDB& txdb, CBlockIndex* pindex)
             return error("ConnectBlock() : UpdateTxIndex failed");
     }
 
-    // ppcoin: fees are not collected by miners as in bitcoin
-    // ppcoin: fees are destroyed to compensate the entire network
-    if (IsProofOfWork() && vtx[0].GetValueOut() > GetProofOfWorkReward(nBits))
-        return false;
-    if (fDebug && GetBoolArg("-printcreation"))
-        printf("ConnectBlock() : destroy=%s nFees=%"PRI64d"\n", FormatMoney(nFees).c_str(), nFees);
-
     // Update block index on disk without changing it in memory.
     // The memory index structure will be changed after the db commits.
     if (pindex->pprev)
@@ -1437,7 +1661,7 @@ bool CBlock::ConnectBlock(CTxDB& txdb, CBlockIndex* pindex)
     return true;
 }
 
-bool Reorganize(CTxDB& txdb, CBlockIndex* pindexNew)
+bool static Reorganize(CTxDB& txdb, CBlockIndex* pindexNew)
 {
     printf("REORGANIZE\n");
 
@@ -1466,8 +1690,8 @@ bool Reorganize(CTxDB& txdb, CBlockIndex* pindexNew)
         vConnect.push_back(pindex);
     reverse(vConnect.begin(), vConnect.end());
 
-    printf("REORGANIZE: Disconnect %i blocks; %s..%s\n", vDisconnect.size(), pfork->GetBlockHash().ToString().substr(0,20).c_str(), pindexBest->GetBlockHash().ToString().substr(0,20).c_str());
-    printf("REORGANIZE: Connect %i blocks; %s..%s\n", vConnect.size(), pfork->GetBlockHash().ToString().substr(0,20).c_str(), pindexNew->GetBlockHash().ToString().substr(0,20).c_str());
+    printf("REORGANIZE: Disconnect %"PRIszu" blocks; %s..%s\n", vDisconnect.size(), pfork->GetBlockHash().ToString().substr(0,20).c_str(), pindexBest->GetBlockHash().ToString().substr(0,20).c_str());
+    printf("REORGANIZE: Connect %"PRIszu" blocks; %s..%s\n", vConnect.size(), pfork->GetBlockHash().ToString().substr(0,20).c_str(), pindexNew->GetBlockHash().ToString().substr(0,20).c_str());
 
     // Disconnect shorter branch
     vector<CTransaction> vResurrect;
@@ -1496,7 +1720,6 @@ bool Reorganize(CTxDB& txdb, CBlockIndex* pindexNew)
         if (!block.ConnectBlock(txdb, pindex))
         {
             // Invalid block
-            txdb.TxnAbort();
             return error("Reorganize() : ConnectBlock %s failed", pindex->GetBlockHash().ToString().substr(0,20).c_str());
         }
 
@@ -1535,14 +1758,6 @@ bool Reorganize(CTxDB& txdb, CBlockIndex* pindexNew)
 }
 
 
-static void
-runCommand(std::string strCommand)
-{
-    int nErr = ::system(strCommand.c_str());
-    if (nErr)
-        printf("runCommand error: system(%s) returned %d\n", strCommand.c_str(), nErr);
-}
-
 // Called from inside SetBestChain: attaches a block to the new best chain being built
 bool CBlock::SetBestChainInner(CTxDB& txdb, CBlockIndex *pindexNew)
 {
@@ -1575,7 +1790,7 @@ bool CBlock::SetBestChain(CTxDB& txdb, CBlockIndex* pindexNew)
     if (!txdb.TxnBegin())
         return error("SetBestChain() : TxnBegin failed");
 
-    if (pindexGenesisBlock == NULL && hash == hashGenesisBlock)
+    if (pindexGenesisBlock == NULL && hash == (!fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet))
     {
         txdb.WriteHashBestChain(hash);
         if (!txdb.TxnCommit())
@@ -1597,14 +1812,14 @@ bool CBlock::SetBestChain(CTxDB& txdb, CBlockIndex* pindexNew)
 
         // Reorganize is costly in terms of db load, as it works in a single db transaction.
         // Try to limit how much needs to be done inside
-        while (pindexIntermediate->pprev && pindexIntermediate->pprev->nChainTrust > pindexBest->nChainTrust)
+        while (pindexIntermediate->pprev && pindexIntermediate->pprev->bnChainTrust > pindexBest->bnChainTrust)
         {
             vpindexSecondary.push_back(pindexIntermediate);
             pindexIntermediate = pindexIntermediate->pprev;
         }
 
         if (!vpindexSecondary.empty())
-            printf("Postponing %i reconnects\n", vpindexSecondary.size());
+            printf("Postponing %"PRIszu" reconnects\n", vpindexSecondary.size());
 
         // Switch to new best branch
         if (!Reorganize(txdb, pindexIntermediate))
@@ -1614,7 +1829,7 @@ bool CBlock::SetBestChain(CTxDB& txdb, CBlockIndex* pindexNew)
             return error("SetBestChain() : Reorganize failed");
         }
 
-        // Connect futher blocks
+        // Connect further blocks
         BOOST_REVERSE_FOREACH(CBlockIndex *pindex, vpindexSecondary)
         {
             CBlock block;
@@ -1644,11 +1859,36 @@ bool CBlock::SetBestChain(CTxDB& txdb, CBlockIndex* pindexNew)
     // New best block
     hashBestChain = hash;
     pindexBest = pindexNew;
+    pblockindexFBBHLast = NULL;
     nBestHeight = pindexBest->nHeight;
-    nBestChainTrust = pindexNew->nChainTrust;
+    bnBestChainTrust = pindexNew->bnChainTrust;
     nTimeBestReceived = GetTime();
     nTransactionsUpdated++;
-    printf("SetBestChain: new best=%s  height=%d  trust=%s\n", hashBestChain.ToString().substr(0,20).c_str(), nBestHeight, CBigNum(nBestChainTrust).ToString().c_str());
+
+    CBigNum bnBestBlockTrust = pindexBest->nHeight != 0 ? (pindexBest->bnChainTrust - pindexBest->pprev->bnChainTrust) : pindexBest->bnChainTrust;
+
+    printf("SetBestChain: new best=%s  height=%d  trust=%s  blocktrust=%s  date=%s\n",
+      hashBestChain.ToString().substr(0,20).c_str(), nBestHeight, bnBestChainTrust.ToString().c_str(),
+      bnBestBlockTrust.ToString().c_str(),
+      DateTimeStrFormat("%x %H:%M:%S", pindexBest->GetBlockTime()).c_str());
+
+    // Check the version of the last 100 blocks to see if we need to upgrade:
+    if (!fIsInitialDownload)
+    {
+        int nUpgraded = 0;
+        const CBlockIndex* pindex = pindexBest;
+        for (int i = 0; i < 100 && pindex != NULL; i++)
+        {
+            if (pindex->nVersion > CBlock::CURRENT_VERSION)
+                ++nUpgraded;
+            pindex = pindex->pprev;
+        }
+        if (nUpgraded > 0)
+            printf("SetBestChain: %d of last 100 blocks above version %d\n", nUpgraded, CBlock::CURRENT_VERSION);
+        if (nUpgraded > 100/2)
+            // strMiscWarning is read by GetWarnings(), called by Qt and the JSON-RPC code to warn the user:
+            strMiscWarning = _("Warning: This version is obsolete, upgrade required!");
+    }
 
     std::string strCmd = GetArg("-blocknotify", "");
 
@@ -1661,70 +1901,6 @@ bool CBlock::SetBestChain(CTxDB& txdb, CBlockIndex* pindexNew)
     return true;
 }
 
-
-// ppcoin: coinstake must meet hash target according to the protocol:
-// input 0 must meet the formula
-//     hash(nBits + txPrev.block.nTime + txPrev.offset + txPrev.nTime + txPrev.vout.n + nTime) < bnTarget * nCoinDay
-// this ensures that the chance of getting a coinstake is proportional to the
-// amount of coin age one owns.
-// The reason this hash is chosen is the following:
-//   nBits: encodes all past block timestamps, making computing hash in advance
-//          more difficult
-//   txPrev.block.nTime: prevent nodes from guessing a good timestamp to
-//                       generate transaction for future advantage
-//   txPrev.offset: offset of txPrev inside block, to reduce the chance of 
-//                  nodes generating coinstake at the same time
-//   txPrev.nTime: reduce the chance of nodes generating coinstake at the same
-//                 time
-//   txPrev.vout.n: output number of txPrev, to reduce the chance of nodes
-//                  generating coinstake at the same time
-//   block/tx hash should not be used here as they can be generated in vast
-//   quantities so as to generate blocks faster, degrading the system back into
-//   a proof-of-work situation.
-//
-bool CTransaction::CheckProofOfStake(unsigned int nBits) const
-{
-    CBigNum bnTargetPerCoinDay;
-    bnTargetPerCoinDay.SetCompact(nBits);
- 
-    if (!IsCoinStake())
-        return true;
-
-    // Input 0 must match the stake hash target per coin age (nBits)
-    const CTxIn& txin = vin[0];
-
-    // First try finding the previous transaction in database
-    CTxDB txdb("r");
-    CTransaction txPrev;
-    CTxIndex txindex;
-    if (!txPrev.ReadFromDisk(txdb, txin.prevout, txindex))
-        return false;  // previous transaction not in main chain
-    txdb.Close();
-    if (nTime < txPrev.nTime)
-        return false;  // Transaction timestamp violation
-
-    // Verify signature
-    if (!VerifySignature(txPrev, *this, 0, true, 0))
-        return DoS(100, error("CheckProofOfStake() : VerifySignature failed on coinstake %s", GetHash().ToString().c_str()));
-
-    // Read block header
-    CBlock block;
-    if (!block.ReadFromDisk(txindex.pos.nFile, txindex.pos.nBlockPos, false))
-        return false; // unable to read block of previous transaction
-    if (block.GetBlockTime() + STAKE_MIN_AGE > nTime)
-        return false; // only count coins meeting min age requirement
-
-    int64 nValueIn = txPrev.vout[txin.prevout.n].nValue;
-    CBigNum bnCoinDay = CBigNum(nValueIn) * (nTime-txPrev.nTime) / COIN / (24 * 60 * 60);
-    // Calculate hash
-    CDataStream ss(SER_GETHASH, 0);
-    ss << nBits << block.nTime << (txindex.pos.nTxPos - txindex.pos.nBlockPos) << txPrev.nTime << txin.prevout.n << nTime;
-    if (CBigNum(Hash(ss.begin(), ss.end())) <= bnCoinDay * bnTargetPerCoinDay)
-        return true;
-    else
-        return DoS(100, error("CheckProofOfStake() : check target failed on coinstake %s", GetHash().ToString().c_str()));
-}
-
 // ppcoin: total coin age spent in transaction, in the unit of coin-days.
 // Only those coins meeting minimum age requirement counts. As those
 // transactions not in main chain are not currently indexed so we
@@ -1754,14 +1930,14 @@ bool CTransaction::GetCoinAge(CTxDB& txdb, uint64& nCoinAge) const
         CBlock block;
         if (!block.ReadFromDisk(txindex.pos.nFile, txindex.pos.nBlockPos, false))
             return false; // unable to read block of previous transaction
-        if (block.GetBlockTime() + STAKE_MIN_AGE > nTime)
+        if (block.GetBlockTime() + nStakeMinAge > nTime)
             continue; // only count coins meeting min age requirement
 
         int64 nValueIn = txPrev.vout[txin.prevout.n].nValue;
         bnCentSecond += CBigNum(nValueIn) * (nTime-txPrev.nTime) / CENT;
 
         if (fDebug && GetBoolArg("-printcoinage"))
-            printf("coin age nValueIn=%-12I64d nTimeDiff=%d bnCentSecond=%s\n", nValueIn, nTime - txPrev.nTime, bnCentSecond.ToString().c_str());
+            printf("coin age nValueIn=%"PRI64d" nTimeDiff=%d bnCentSecond=%s\n", nValueIn, nTime - txPrev.nTime, bnCentSecond.ToString().c_str());
     }
 
     CBigNum bnCoinDay = bnCentSecond * CENT / COIN / (24 * 60 * 60);
@@ -1793,7 +1969,6 @@ bool CBlock::GetCoinAge(uint64& nCoinAge) const
     return true;
 }
 
-
 bool CBlock::AddToBlockIndex(unsigned int nFile, unsigned int nBlockPos)
 {
     // Check for duplicate
@@ -1805,11 +1980,7 @@ bool CBlock::AddToBlockIndex(unsigned int nFile, unsigned int nBlockPos)
     CBlockIndex* pindexNew = new CBlockIndex(nFile, nBlockPos, *this);
     if (!pindexNew)
         return error("AddToBlockIndex() : new CBlockIndex failed");
-    map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.insert(make_pair(hash, pindexNew)).first;
-    if (pindexNew->fProofOfStake) 
-        setStakeSeen.insert(make_pair(pindexNew->prevoutStake, pindexNew->nStakeTime));
-
-    pindexNew->phashBlock = &((*mi).first);
+    pindexNew->phashBlock = &hash;
     map<uint256, CBlockIndex*>::iterator miPrev = mapBlockIndex.find(hashPrevBlock);
     if (miPrev != mapBlockIndex.end())
     {
@@ -1818,11 +1989,37 @@ bool CBlock::AddToBlockIndex(unsigned int nFile, unsigned int nBlockPos)
     }
 
     // ppcoin: compute chain trust score
-    uint64 nCoinAge;
-    if (!GetCoinAge(nCoinAge))
-        return error("AddToBlockIndex() : invalid transaction in block");
-    pindexNew->nChainTrust = (pindexNew->pprev ? pindexNew->pprev->nChainTrust : 0) + nCoinAge;
+    pindexNew->bnChainTrust = (pindexNew->pprev ? pindexNew->pprev->bnChainTrust : 0) + pindexNew->GetBlockTrust();
+
+    // ppcoin: compute stake entropy bit for stake modifier
+    if (!pindexNew->SetStakeEntropyBit(GetStakeEntropyBit(pindexNew->nHeight)))
+        return error("AddToBlockIndex() : SetStakeEntropyBit() failed");
+
+    // ppcoin: record proof-of-stake hash value
+    if (pindexNew->IsProofOfStake())
+    {
+        if (!mapProofOfStake.count(hash))
+            return error("AddToBlockIndex() : hashProofOfStake not found in map");
+        pindexNew->hashProofOfStake = mapProofOfStake[hash];
+    }
 
+    // ppcoin: compute stake modifier
+    uint64 nStakeModifier = 0;
+    bool fGeneratedStakeModifier = false;
+    if (!ComputeNextStakeModifier(pindexNew->pprev, nStakeModifier, fGeneratedStakeModifier))
+        return error("AddToBlockIndex() : ComputeNextStakeModifier() failed");
+    pindexNew->SetStakeModifier(nStakeModifier, fGeneratedStakeModifier);
+    pindexNew->nStakeModifierChecksum = GetStakeModifierChecksum(pindexNew);
+    if (!CheckStakeModifierCheckpoints(pindexNew->nHeight, pindexNew->nStakeModifierChecksum))
+        return error("AddToBlockIndex() : Rejected by stake modifier checkpoint height=%d, modifier=0x%016"PRI64x, pindexNew->nHeight, nStakeModifier);
+
+    // Add to mapBlockIndex
+    map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.insert(make_pair(hash, pindexNew)).first;
+    if (pindexNew->IsProofOfStake())
+        setStakeSeen.insert(make_pair(pindexNew->prevoutStake, pindexNew->nStakeTime));
+    pindexNew->phashBlock = &((*mi).first);
+
+    // Write to disk block index
     CTxDB txdb;
     if (!txdb.TxnBegin())
         return false;
@@ -1831,7 +2028,7 @@ bool CBlock::AddToBlockIndex(unsigned int nFile, unsigned int nBlockPos)
         return false;
 
     // New best
-    if (pindexNew->nChainTrust > nBestChainTrust)
+    if (pindexNew->bnChainTrust > bnBestChainTrust)
         if (!SetBestChain(txdb, pindexNew))
             return false;
 
@@ -1845,14 +2042,14 @@ bool CBlock::AddToBlockIndex(unsigned int nFile, unsigned int nBlockPos)
         hashPrevBestCoinBase = vtx[0].GetHash();
     }
 
-    MainFrameRepaint();
+    uiInterface.NotifyBlocksChanged();
     return true;
 }
 
 
 
 
-bool CBlock::CheckBlock() const
+bool CBlock::CheckBlock(bool fCheckPOW, bool fCheckMerkleRoot) const
 {
     // These are checks that are independent of context
     // that can be verified before saving an orphan block.
@@ -1861,8 +2058,26 @@ bool CBlock::CheckBlock() const
     if (vtx.empty() || vtx.size() > MAX_BLOCK_SIZE || ::GetSerializeSize(*this, SER_NETWORK, PROTOCOL_VERSION) > MAX_BLOCK_SIZE)
         return DoS(100, error("CheckBlock() : size limits failed"));
 
+    // Special short-term limits to avoid 10,000 BDB lock limit:
+    if (GetBlockTime() < LOCKS_SWITCH_TIME)
+    {
+        // Rule is: #unique txids referenced <= 4,500
+        // ... to prevent 10,000 BDB lock exhaustion on old clients
+        set<uint256> setTxIn;
+        for (size_t i = 0; i < vtx.size(); i++)
+        {
+            setTxIn.insert(vtx[i].GetHash());
+            if (i == 0) continue; // skip coinbase txin
+            BOOST_FOREACH(const CTxIn& txin, vtx[i].vin)
+                    setTxIn.insert(txin.prevout.hash);
+        }
+        size_t nTxids = setTxIn.size();
+        if (nTxids > 4500)
+            return error("CheckBlock() : maxlocks violation");
+    }
+
     // Check proof of work matches claimed amount
-    if (IsProofOfWork() && !CheckProofOfWork(GetHash(), nBits))
+    if (fCheckPOW && IsProofOfWork() && !CheckProofOfWork(GetHash(), nBits))
         return DoS(50, error("CheckBlock() : proof of work failed"));
 
     // Check timestamp
@@ -1876,28 +2091,45 @@ bool CBlock::CheckBlock() const
         if (vtx[i].IsCoinBase())
             return DoS(100, error("CheckBlock() : more than one coinbase"));
 
-    // ppcoin: only the second transaction can be the optional coinstake
-    for (int i = 2; i < vtx.size(); i++)
-        if (vtx[i].IsCoinStake())
-            return DoS(100, error("CheckBlock() : coinstake in wrong position"));
-
-    // ppcoin: coinbase output should be empty if proof-of-stake block
-    if (IsProofOfStake() && !vtx[0].vout[0].IsEmpty())
-        return error("CheckBlock() : coinbase output not empty for proof-of-stake block");
-
     // Check coinbase timestamp
     if (GetBlockTime() > (int64)vtx[0].nTime + nMaxClockDrift)
         return DoS(50, error("CheckBlock() : coinbase timestamp is too early"));
 
-    // Check coinstake timestamp
-    if (IsProofOfStake() && GetBlockTime() > (int64)vtx[1].nTime + nMaxClockDrift)
-        return DoS(50, error("CheckBlock() : coinstake timestamp is too early"));
+    if (IsProofOfStake())
+    {
+        // ppcoin: coinbase output should be empty if proof-of-stake block
+        if (vtx[0].vout.size() != 1 || !vtx[0].vout[0].IsEmpty())
+            return error("CheckBlock() : coinbase output not empty for proof-of-stake block");
+
+        // Second transaction must be coinstake, the rest must not be
+        if (vtx.empty() || !vtx[1].IsCoinStake())
+            return DoS(100, error("CheckBlock() : second tx is not coinstake"));
+        for (unsigned int i = 2; i < vtx.size(); i++)
+            if (vtx[i].IsCoinStake())
+                return DoS(100, error("CheckBlock() : more than one coinstake"));
+
+        // Check coinstake timestamp
+        if (!CheckCoinStakeTimestamp(GetBlockTime(), (int64)vtx[1].nTime))
+            return DoS(50, error("CheckBlock() : coinstake timestamp violation nTimeBlock=%"PRI64d" nTimeTx=%u", GetBlockTime(), vtx[1].nTime));
+    }
+    else
+    {
+        // Coinbase fee paid until 20 Sep 2013
+        int64 nFee = GetBlockTime() < CHAINCHECKS_SWITCH_TIME ? vtx[0].GetMinFee() - MIN_TX_FEE : 0;
+
+        // Check coinbase reward
+        if (vtx[0].GetValueOut() > (GetProofOfWorkReward(nBits) - nFee))
+            return DoS(50, error("CheckBlock() : coinbase reward exceeded %s > %s", 
+                   FormatMoney(vtx[0].GetValueOut()).c_str(),
+                   FormatMoney(GetProofOfWorkReward(nBits) - nFee).c_str()));
+    }
 
     // Check transactions
     BOOST_FOREACH(const CTransaction& tx, vtx)
     {
         if (!tx.CheckTransaction())
             return DoS(tx.nDoS, error("CheckBlock() : CheckTransaction failed"));
+
         // ppcoin: check transaction timestamp
         if (GetBlockTime() < (int64)tx.nTime)
             return DoS(50, error("CheckBlock() : block timestamp earlier than transaction timestamp"));
@@ -1921,13 +2153,16 @@ bool CBlock::CheckBlock() const
     if (nSigOps > MAX_BLOCK_SIGOPS)
         return DoS(100, error("CheckBlock() : out-of-bounds SigOpCount"));
 
-    // Check merkleroot
-    if (hashMerkleRoot != BuildMerkleTree())
+    // Check merkle root
+    if (fCheckMerkleRoot && hashMerkleRoot != BuildMerkleTree())
         return DoS(100, error("CheckBlock() : hashMerkleRoot mismatch"));
 
-    // ppcoin: check block signature
-    if (!CheckBlockSignature())
-        return DoS(100, error("CheckBlock() : bad block signature"));
+    // NovaCoin: check proof-of-stake block signature
+    if (IsProofOfStake() || (!fTestNet && GetBlockTime() < CHAINCHECKS_SWITCH_TIME))
+    {
+        if (!CheckBlockSignature())
+            return DoS(100, error("CheckBlock() : bad block signature"));
+    }
 
     return true;
 }
@@ -1948,7 +2183,7 @@ bool CBlock::AcceptBlock()
 
     // Check proof-of-work or proof-of-stake
     if (nBits != GetNextTargetRequired(pindexPrev, IsProofOfStake()))
-        return DoS(100, error("AcceptBlock() : incorrect proof-of-work/proof-of-stake"));
+        return DoS(100, error("AcceptBlock() : incorrect %s", IsProofOfWork() ? "proof-of-work" : "proof-of-stake"));
 
     // Check timestamp against prev
     if (GetBlockTime() <= pindexPrev->GetMedianTimePast() || GetBlockTime() + nMaxClockDrift < pindexPrev->GetBlockTime())
@@ -1959,13 +2194,31 @@ bool CBlock::AcceptBlock()
         if (!tx.IsFinal(nHeight, GetBlockTime()))
             return DoS(10, error("AcceptBlock() : contains a non-final transaction"));
 
-    // Check that the block chain matches the known block chain up to a hardened checkpoint
+    // Check that the block chain matches the known block chain up to a checkpoint
     if (!Checkpoints::CheckHardened(nHeight, hash))
-        return DoS(100, error("AcceptBlock() : rejected by hardened checkpoint lockin at %d", nHeight));
+        return DoS(100, error("AcceptBlock() : rejected by hardened checkpoint lock-in at %d", nHeight));
 
     // ppcoin: check that the block satisfies synchronized checkpoint
     if (!Checkpoints::CheckSync(hash, pindexPrev))
-        return error("AcceptBlock() : rejected by synchronized checkpoint");
+    {
+        if(!GetBoolArg("-nosynccheckpoints", false))
+        {
+            return error("AcceptBlock() : rejected by synchronized checkpoint");
+        }
+        else
+        {
+            strMiscWarning = _("WARNING: syncronized checkpoint violation detected, but skipped!");
+        }
+    }
+
+    // Reject block.nVersion < 3 blocks since 95% threshold on mainNet and always on testNet:
+    if (nVersion < 3 && ((!fTestNet && nHeight > 14060) || (fTestNet && nHeight > 0)))
+        return error("CheckBlock() : rejected nVersion < 3 block");
+
+    // Enforce rule that the coinbase starts with serialized block height
+    CScript expect = CScript() << nHeight;
+    if (!std::equal(expect.begin(), expect.end(), vtx[0].vin[0].scriptSig.begin()))
+        return DoS(100, error("AcceptBlock() : block height mismatch in coinbase"));
 
     // Write block to history file
     if (!CheckDiskSpace(::GetSerializeSize(*this, SER_DISK, CLIENT_VERSION)))
@@ -1993,6 +2246,87 @@ bool CBlock::AcceptBlock()
     return true;
 }
 
+CBigNum CBlockIndex::GetBlockTrust() const
+{
+    CBigNum bnTarget;
+
+    // Old protocol
+    if (!fTestNet && GetBlockTime() < CHAINCHECKS_SWITCH_TIME)
+    {
+        CBigNum bnTarget;
+        bnTarget.SetCompact(nBits);
+
+        if (bnTarget <= 0)
+            return 0;
+        return (IsProofOfStake()? (CBigNum(1)<<256) / (bnTarget+1) : 1);
+    }
+
+    // New protocol
+    if (pprev == NULL || pprev->nHeight < 10)
+        return 1;
+
+    const CBlockIndex* currentIndex = pprev;
+
+    if(IsProofOfStake())
+    {
+        bnTarget.SetCompact(nBits);
+        if (bnTarget <= 0)
+            return 0;
+
+        if (!pprev->IsProofOfWork())
+            return (CBigNum(1)<<256) / (3 * (bnTarget+1));
+
+        int nPoWCount = 0;
+
+        // Check last 12 blocks type
+        while (pprev->nHeight - currentIndex->nHeight < 12)
+        {
+            if (currentIndex->IsProofOfWork())
+                nPoWCount++;
+            currentIndex = currentIndex->pprev;
+        }
+
+        // Return 1/3 of score if less than 3 PoW blocks found
+        if (nPoWCount < 3)
+            return (CBigNum(1)<<256) / (3 * (bnTarget+1));
+
+        return (CBigNum(1)<<256) / (bnTarget+1);
+    }
+    else
+    {
+        if (!(pprev->IsProofOfStake() && pprev->pprev->IsProofOfStake()))
+            return 1 + (2 * (pprev->bnChainTrust - pprev->pprev->bnChainTrust) / 3);
+
+        int nPoSCount = 0;
+
+        // Check last 12 blocks type
+        while (pprev->nHeight - currentIndex->nHeight < 12)
+        {
+            if (currentIndex->IsProofOfStake())
+                nPoSCount++;
+            currentIndex = currentIndex->pprev;
+        }
+
+        // Return 2/3 of previous block score if less than 7 PoS blocks found
+        if (nPoSCount < 7)
+            return 1 + (2 * (pprev->bnChainTrust - pprev->pprev->bnChainTrust) / 3);
+
+        return (pprev->bnChainTrust - pprev->pprev->bnChainTrust);
+    }
+}
+
+bool CBlockIndex::IsSuperMajority(int minVersion, const CBlockIndex* pstart, unsigned int nRequired, unsigned int nToCheck)
+{
+    unsigned int nFound = 0;
+    for (unsigned int i = 0; i < nToCheck && nFound < nRequired && pstart != NULL; i++)
+    {
+        if (pstart->nVersion >= minVersion)
+            ++nFound;
+        pstart = pstart->pprev;
+    }
+    return (nFound >= nRequired);
+}
+
 bool ProcessBlock(CNode* pfrom, CBlock* pblock)
 {
     // Check for duplicate
@@ -2013,10 +2347,16 @@ bool ProcessBlock(CNode* pfrom, CBlock* pblock)
         return error("ProcessBlock() : CheckBlock FAILED");
 
     // ppcoin: verify hash target and signature of coinstake tx
-    if (pblock->IsProofOfStake() && !pblock->vtx[1].CheckProofOfStake(pblock->nBits))
+    if (pblock->IsProofOfStake())
     {
-        printf("WARNING: ProcessBlock(): check proof-of-stake failed for block %s\n", hash.ToString().c_str());
-        return false; // do not error here as we expect this during initial block download
+        uint256 hashProofOfStake = 0;
+        if (!CheckProofOfStake(pblock->vtx[1], pblock->nBits, hashProofOfStake))
+        {
+            printf("WARNING: ProcessBlock(): check proof-of-stake failed for block %s\n", hash.ToString().c_str());
+            return false; // do not error here as we expect this during initial block download
+        }
+        if (!mapProofOfStake.count(hash)) // add to mapProofOfStake
+            mapProofOfStake.insert(make_pair(hash, hashProofOfStake));
     }
 
     CBlockIndex* pcheckpoint = Checkpoints::GetLastSyncCheckpoint();
@@ -2028,7 +2368,6 @@ bool ProcessBlock(CNode* pfrom, CBlock* pblock)
         bnNewBlock.SetCompact(pblock->nBits);
         CBigNum bnRequired;
         bnRequired.SetCompact(ComputeMinWork(GetLastBlockIndex(pcheckpoint, pblock->IsProofOfStake())->nBits, deltaTime));
-
         if (bnNewBlock > bnRequired)
         {
             if (pfrom)
@@ -2109,77 +2448,142 @@ bool CBlock::SignBlock(const CKeyStore& keystore)
 {
     vector<valtype> vSolutions;
     txnouttype whichType;
-    const CTxOut& txout = IsProofOfStake()? vtx[1].vout[1] : vtx[0].vout[0];
 
-    if (!Solver(txout.scriptPubKey, whichType, vSolutions))
-        return false;
-    if (whichType == TX_PUBKEY)
+    if(!IsProofOfStake())
     {
-        // Sign
-        const valtype& vchPubKey = vSolutions[0];
-        CKey key;
-        if (!keystore.GetKey(Hash160(vchPubKey), key))
-            return false;
-        if (key.GetPubKey() != vchPubKey)
+        for(unsigned int i = 0; i < vtx[0].vout.size(); i++)
+        {
+            const CTxOut& txout = vtx[0].vout[i];
+
+            if (!Solver(txout.scriptPubKey, whichType, vSolutions))
+                continue;
+
+            if (whichType == TX_PUBKEY)
+            {
+                // Sign
+                valtype& vchPubKey = vSolutions[0];
+                CKey key;
+
+                if (!keystore.GetKey(Hash160(vchPubKey), key))
+                    continue;
+                if (key.GetPubKey() != vchPubKey)
+                    continue;
+                if(!key.Sign(GetHash(), vchBlockSig))
+                    continue;
+
+                return true;
+            }
+        }
+    }
+    else
+    {
+        const CTxOut& txout = vtx[1].vout[1];
+
+        if (!Solver(txout.scriptPubKey, whichType, vSolutions))
             return false;
-        return key.Sign(GetHash(), vchBlockSig);
+
+        if (whichType == TX_PUBKEY)
+        {
+            // Sign
+            valtype& vchPubKey = vSolutions[0];
+            CKey key;
+
+            if (!keystore.GetKey(Hash160(vchPubKey), key))
+                return false;
+            if (key.GetPubKey() != vchPubKey)
+                return false;
+
+            return key.Sign(GetHash(), vchBlockSig);
+        }
     }
+
+    printf("Sign failed\n");
     return false;
 }
 
 // ppcoin: check block signature
 bool CBlock::CheckBlockSignature() const
 {
-    if (GetHash() == hashGenesisBlock)
+    if (GetHash() == (!fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet))
         return vchBlockSig.empty();
 
     vector<valtype> vSolutions;
     txnouttype whichType;
-    const CTxOut& txout = IsProofOfStake()? vtx[1].vout[1] : vtx[0].vout[0];
 
-    if (!Solver(txout.scriptPubKey, whichType, vSolutions))
-        return false;
-    if (whichType == TX_PUBKEY)
+    if(IsProofOfStake())
     {
-        const valtype& vchPubKey = vSolutions[0];
-        CKey key;
-        if (!key.SetPubKey(vchPubKey))
-            return false;
-        if (vchBlockSig.empty())
+        const CTxOut& txout = vtx[1].vout[1];
+
+        if (!Solver(txout.scriptPubKey, whichType, vSolutions))
             return false;
-        return key.Verify(GetHash(), vchBlockSig);
+        if (whichType == TX_PUBKEY)
+        {
+            valtype& vchPubKey = vSolutions[0];
+            CKey key;
+            if (!key.SetPubKey(vchPubKey))
+                return false;
+            if (vchBlockSig.empty())
+                return false;
+            return key.Verify(GetHash(), vchBlockSig);
+        }
     }
-    return false;
-}
-
-
+    else
+    {
+        for(unsigned int i = 0; i < vtx[0].vout.size(); i++)
+        {
+            const CTxOut& txout = vtx[0].vout[i];
 
+            if (!Solver(txout.scriptPubKey, whichType, vSolutions))
+                return false;
 
+            if (whichType == TX_PUBKEY)
+            {
+                // Verify
+                valtype& vchPubKey = vSolutions[0];
+                CKey key;
+                if (!key.SetPubKey(vchPubKey))
+                    continue;
+                if (vchBlockSig.empty())
+                    continue;
+                if(!key.Verify(GetHash(), vchBlockSig))
+                    continue;
 
+                return true;
+            }
+        }
+    }
+    return false;
+}
 
 bool CheckDiskSpace(uint64 nAdditionalBytes)
 {
     uint64 nFreeBytesAvailable = filesystem::space(GetDataDir()).available;
 
-    // Check for 15MB because database could create another 10MB log file at any time
-    if (nFreeBytesAvailable < (uint64)15000000 + nAdditionalBytes)
+    // Check for nMinDiskSpace bytes (currently 50MB)
+    if (nFreeBytesAvailable < nMinDiskSpace + nAdditionalBytes)
     {
         fShutdown = true;
-        string strMessage = _("Warning: Disk space is low");
+        string strMessage = _("Warning: Disk space is low!");
         strMiscWarning = strMessage;
         printf("*** %s\n", strMessage.c_str());
-        ThreadSafeMessageBox(strMessage, "PPCoin", wxOK | wxICON_EXCLAMATION | wxMODAL);
+        uiInterface.ThreadSafeMessageBox(strMessage, "NovaCoin", CClientUIInterface::OK | CClientUIInterface::ICON_EXCLAMATION | CClientUIInterface::MODAL);
         StartShutdown();
         return false;
     }
     return true;
 }
 
+static filesystem::path BlockFilePath(unsigned int nFile)
+{
+    string strBlockFn = strprintf("blk%04u.dat", nFile);
+    return GetDataDir() / strBlockFn;
+}
+
 FILE* OpenBlockFile(unsigned int nFile, unsigned int nBlockPos, const char* pszMode)
 {
-    if (nFile == -1)
+    if ((nFile < 1) || (nFile == (unsigned int) -1))
         return NULL;
-    FILE* file = fopen((GetDataDir() / strprintf("blk%04d.dat", nFile)).string().c_str(), pszMode);
+    FILE* file = fopen(BlockFilePath(nFile).string().c_str(), pszMode);
     if (!file)
         return NULL;
     if (nBlockPos != 0 && !strchr(pszMode, 'a') && !strchr(pszMode, 'w'))
@@ -2205,8 +2609,8 @@ FILE* AppendBlockFile(unsigned int& nFileRet)
             return NULL;
         if (fseek(file, 0, SEEK_END) != 0)
             return NULL;
-        // FAT32 filesize max 4GB, fseek and ftell max 2GB, so we must stay under 2GB
-        if (ftell(file) < 0x7F000000 - MAX_SIZE)
+        // FAT32 file size max 4GB, fseek and ftell max 2GB, so we must stay under 2GB
+        if (ftell(file) < (long)(0x7F000000 - MAX_SIZE))
         {
             nFileRet = nCurrentBlockFile;
             return file;
@@ -2220,12 +2624,16 @@ bool LoadBlockIndex(bool fAllowNew)
 {
     if (fTestNet)
     {
-        hashGenesisBlock = hashGenesisBlockTestNet;
-        bnProofOfWorkLimit = CBigNum(~uint256(0) >> 28);
-        pchMessageStart[0] = 0xfa;
-        pchMessageStart[1] = 0xbf;
-        pchMessageStart[2] = 0xb5;
-        pchMessageStart[3] = 0xda;
+        pchMessageStart[0] = 0xcd;
+        pchMessageStart[1] = 0xf2;
+        pchMessageStart[2] = 0xc0;
+        pchMessageStart[3] = 0xef;
+
+        bnProofOfWorkLimit = bnProofOfWorkLimitTestNet; // 16 bits PoW target limit for testnet
+        nStakeMinAge = 2 * 60 * 60; // test net min age is 2 hours
+        nModifierInterval = 20 * 60; // test modifier interval is 20 minutes
+        nCoinbaseMaturity = 10; // test maturity is 10 blocks
+        nStakeTargetSpacing = 5 * 60; // test block spacing is 5 minutes
     }
 
     //
@@ -2244,17 +2652,27 @@ bool LoadBlockIndex(bool fAllowNew)
         if (!fAllowNew)
             return false;
 
-        // Genesis Block:
-        // CBlock(hash=000000000019d6, ver=1, hashPrevBlock=00000000000000, hashMerkleRoot=4a5e1e, nTime=1231006505, nBits=1d00ffff, nNonce=2083236893, vtx=1)
-        //   CTransaction(hash=4a5e1e, ver=1, vin.size=1, vout.size=1, nLockTime=0)
-        //     CTxIn(COutPoint(000000, -1), coinbase 04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73)
-        //     CTxOut(nValue=50.00000000, scriptPubKey=0x5F1DF16B2B704C8A578D0B)
-        //   vMerkleTree: 4a5e1e
-
         // Genesis block
-        const char* pszTimestamp = "Matonis 07-AUG-2012 Parallel Currencies And The Roadmap To Monetary Freedom";
+
+        // MainNet:
+
+        //CBlock(hash=00000a060336cbb72fe969666d337b87198b1add2abaa59cca226820b32933a4, ver=1, hashPrevBlock=0000000000000000000000000000000000000000000000000000000000000000, hashMerkleRoot=4cb33b3b6a861dcbc685d3e614a9cafb945738d6833f182855679f2fad02057b, nTime=1360105017, nBits=1e0fffff, nNonce=1575379, vtx=1, vchBlockSig=)
+        //  Coinbase(hash=4cb33b3b6a, nTime=1360105017, ver=1, vin.size=1, vout.size=1, nLockTime=0)
+        //    CTxIn(COutPoint(0000000000, 4294967295), coinbase 04ffff001d020f274468747470733a2f2f626974636f696e74616c6b2e6f72672f696e6465782e7068703f746f7069633d3133343137392e6d736731353032313936236d736731353032313936)
+        //    CTxOut(empty)
+        //  vMerkleTree: 4cb33b3b6a
+
+        // TestNet:
+
+        //CBlock(hash=0000c763e402f2436da9ed36c7286f62c3f6e5dbafce9ff289bd43d7459327eb, ver=1, hashPrevBlock=0000000000000000000000000000000000000000000000000000000000000000, hashMerkleRoot=4cb33b3b6a861dcbc685d3e614a9cafb945738d6833f182855679f2fad02057b, nTime=1360105017, nBits=1f00ffff, nNonce=46534, vtx=1, vchBlockSig=)
+        //  Coinbase(hash=4cb33b3b6a, nTime=1360105017, ver=1, vin.size=1, vout.size=1, nLockTime=0)
+        //    CTxIn(COutPoint(0000000000, 4294967295), coinbase 04ffff001d020f274468747470733a2f2f626974636f696e74616c6b2e6f72672f696e6465782e7068703f746f7069633d3133343137392e6d736731353032313936236d736731353032313936)
+        //    CTxOut(empty)
+        //  vMerkleTree: 4cb33b3b6a
+
+        const char* pszTimestamp = "https://bitcointalk.org/index.php?topic=134179.msg1502196#msg1502196";
         CTransaction txNew;
-        txNew.nTime = 1345083810;
+        txNew.nTime = 1360105017;
         txNew.vin.resize(1);
         txNew.vout.resize(1);
         txNew.vin[0].scriptSig = CScript() << 486604799 << CBigNum(9999) << vector<unsigned char>((const unsigned char*)pszTimestamp, (const unsigned char*)pszTimestamp + strlen(pszTimestamp));
@@ -2264,23 +2682,14 @@ bool LoadBlockIndex(bool fAllowNew)
         block.hashPrevBlock = 0;
         block.hashMerkleRoot = block.BuildMerkleTree();
         block.nVersion = 1;
-        block.nTime    = 1345084287;
+        block.nTime    = 1360105017;
         block.nBits    = bnProofOfWorkLimit.GetCompact();
-        block.nNonce   = 2179302059;
-
-        if (fTestNet)
-        {
-            block.nTime    = 1345090000;
-            block.nNonce   = 122894938;
-        }
+        block.nNonce   = !fTestNet ? 1575379 : 46534;
 
         //// debug print
-        printf("%s\n", block.GetHash().ToString().c_str());
-        printf("%s\n", hashGenesisBlock.ToString().c_str());
-        printf("%s\n", block.hashMerkleRoot.ToString().c_str());
-        assert(block.hashMerkleRoot == uint256("0x3c2d8f85fab4d17aac558cc648a1a58acff0de6deb890c29985690052c5993c2"));
+        assert(block.hashMerkleRoot == uint256("0x4cb33b3b6a861dcbc685d3e614a9cafb945738d6833f182855679f2fad02057b"));
         block.print();
-        assert(block.GetHash() == hashGenesisBlock);
+        assert(block.GetHash() == (!fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet));
         assert(block.CheckBlock());
 
         // Start new block file
@@ -2292,7 +2701,7 @@ bool LoadBlockIndex(bool fAllowNew)
             return error("LoadBlockIndex() : genesis block not accepted");
 
         // ppcoin: initialize synchronized checkpoint
-        if (!Checkpoints::WriteSyncCheckpoint(hashGenesisBlock))
+        if (!Checkpoints::WriteSyncCheckpoint((!fTestNet ? hashGenesisBlock : hashGenesisBlockTestNet)))
             return error("LoadBlockIndex() : failed to init sync checkpoint");
     }
 
@@ -2308,7 +2717,7 @@ bool LoadBlockIndex(bool fAllowNew)
                 return error("LoadBlockIndex() : failed to write new checkpoint master key to db");
             if (!txdb.TxnCommit())
                 return error("LoadBlockIndex() : failed to commit new checkpoint master key to db");
-            if (!Checkpoints::ResetSyncCheckpoint())
+            if ((!fTestNet) && !Checkpoints::ResetSyncCheckpoint())
                 return error("LoadBlockIndex() : failed to reset sync-checkpoint");
         }
         txdb.Close();
@@ -2321,7 +2730,7 @@ bool LoadBlockIndex(bool fAllowNew)
 
 void PrintBlockTree()
 {
-    // precompute tree structure
+    // pre-compute tree structure
     map<CBlockIndex*, vector<CBlockIndex*> > mapNext;
     for (map<uint256, CBlockIndex*>::iterator mi = mapBlockIndex.begin(); mi != mapBlockIndex.end(); ++mi)
     {
@@ -2364,18 +2773,19 @@ void PrintBlockTree()
         // print item
         CBlock block;
         block.ReadFromDisk(pindex);
-        printf("%d (%u,%u) %s  %08lx  %s  tx %d",
+        printf("%d (%u,%u) %s  %08x  %s  mint %7s  tx %"PRIszu"",
             pindex->nHeight,
             pindex->nFile,
             pindex->nBlockPos,
-            block.GetHash().ToString().substr(0,20).c_str(),
+            block.GetHash().ToString().c_str(),
             block.nBits,
-            DateTimeStrFormat(block.GetBlockTime()).c_str(),
+            DateTimeStrFormat("%x %H:%M:%S", block.GetBlockTime()).c_str(),
+            FormatMoney(pindex->nMint).c_str(),
             block.vtx.size());
 
         PrintWallets(block);
 
-        // put the main timechain first
+        // put the main time-chain first
         vector<CBlockIndex*>& vNext = mapNext[pindex];
         for (unsigned int i = 0; i < vNext.size(); i++)
         {
@@ -2392,6 +2802,65 @@ void PrintBlockTree()
     }
 }
 
+bool LoadExternalBlockFile(FILE* fileIn)
+{
+    int64 nStart = GetTimeMillis();
+
+    int nLoaded = 0;
+    {
+        LOCK(cs_main);
+        try {
+            CAutoFile blkdat(fileIn, SER_DISK, CLIENT_VERSION);
+            unsigned int nPos = 0;
+            while (nPos != (unsigned int)-1 && blkdat.good() && !fRequestShutdown)
+            {
+                unsigned char pchData[65536];
+                do {
+                    fseek(blkdat, nPos, SEEK_SET);
+                    int nRead = fread(pchData, 1, sizeof(pchData), blkdat);
+                    if (nRead <= 8)
+                    {
+                        nPos = (unsigned int)-1;
+                        break;
+                    }
+                    void* nFind = memchr(pchData, pchMessageStart[0], nRead+1-sizeof(pchMessageStart));
+                    if (nFind)
+                    {
+                        if (memcmp(nFind, pchMessageStart, sizeof(pchMessageStart))==0)
+                        {
+                            nPos += ((unsigned char*)nFind - pchData) + sizeof(pchMessageStart);
+                            break;
+                        }
+                        nPos += ((unsigned char*)nFind - pchData) + 1;
+                    }
+                    else
+                        nPos += sizeof(pchData) - sizeof(pchMessageStart) + 1;
+                } while(!fRequestShutdown);
+                if (nPos == (unsigned int)-1)
+                    break;
+                fseek(blkdat, nPos, SEEK_SET);
+                unsigned int nSize;
+                blkdat >> nSize;
+                if (nSize > 0 && nSize <= MAX_BLOCK_SIZE)
+                {
+                    CBlock block;
+                    blkdat >> block;
+                    if (ProcessBlock(NULL,&block))
+                    {
+                        nLoaded++;
+                        nPos += 4 + nSize;
+                    }
+                }
+            }
+        }
+        catch (std::exception &e) {
+            printf("%s() : Deserialize or I/O error caught during load\n",
+                   __PRETTY_FUNCTION__);
+        }
+    }
+    printf("Loaded %i blocks from external file in %"PRI64d"ms\n", nLoaded, GetTimeMillis() - nStart);
+    return nLoaded > 0;
+}
 
 
 
@@ -2406,10 +2875,10 @@ void PrintBlockTree()
 // CAlert
 //
 
-map<uint256, CAlert> mapAlerts;
-CCriticalSection cs_mapAlerts;
+extern map<uint256, CAlert> mapAlerts;
+extern CCriticalSection cs_mapAlerts;
 
-static string strMintMessage = _("Info: Minting suspended due to locked wallet."); 
+static string strMintMessage = "Info: Minting suspended due to locked wallet.";
 static string strMintWarning;
 
 string GetWarnings(string strFor)
@@ -2417,6 +2886,7 @@ string GetWarnings(string strFor)
     int nPriority = 0;
     string strStatusBar;
     string strRPC;
+
     if (GetBoolArg("-testsafemode"))
         strRPC = "test";
 
@@ -2435,18 +2905,18 @@ string GetWarnings(string strFor)
     }
 
     // ppcoin: should not enter safe mode for longer invalid chain
-    // ppcoin: if sync-checkpoint too old enter safe mode
-    if (Checkpoints::IsMatureSyncCheckpoint())
+    // ppcoin: if sync-checkpoint is too old do not enter safe mode
+    if (Checkpoints::IsSyncCheckpointTooOld(60 * 60 * 24 * 10) && !fTestNet && !IsInitialBlockDownload())
     {
-        nPriority = 2000;
-        strStatusBar = strRPC = "WARNING: Checkpoint is too old. Wait for block chain to download, or notify developers of the issue.";
+        nPriority = 100;
+        strStatusBar = "WARNING: Checkpoint is too old. Wait for block chain to download, or notify developers.";
     }
 
     // ppcoin: if detected invalid checkpoint enter safe mode
     if (Checkpoints::hashInvalidCheckpoint != 0)
     {
         nPriority = 3000;
-        strStatusBar = strRPC = "WARNING: Invalid checkpoint found! Displayed transactions may not be correct! You may need to upgrade, or notify developers of the issue.";
+        strStatusBar = strRPC = "WARNING: Invalid checkpoint found! Displayed transactions may not be correct! You may need to upgrade, or notify developers.";
     }
 
     // Alerts
@@ -2473,53 +2943,6 @@ string GetWarnings(string strFor)
     return "error";
 }
 
-bool CAlert::ProcessAlert()
-{
-    if (!CheckSignature())
-        return false;
-    if (!IsInEffect())
-        return false;
-
-    {
-        LOCK(cs_mapAlerts);
-        // Cancel previous alerts
-        for (map<uint256, CAlert>::iterator mi = mapAlerts.begin(); mi != mapAlerts.end();)
-        {
-            const CAlert& alert = (*mi).second;
-            if (Cancels(alert))
-            {
-                printf("cancelling alert %d\n", alert.nID);
-                mapAlerts.erase(mi++);
-            }
-            else if (!alert.IsInEffect())
-            {
-                printf("expiring alert %d\n", alert.nID);
-                mapAlerts.erase(mi++);
-            }
-            else
-                mi++;
-        }
-
-        // Check if this alert has been cancelled
-        BOOST_FOREACH(PAIRTYPE(const uint256, CAlert)& item, mapAlerts)
-        {
-            const CAlert& alert = item.second;
-            if (alert.Cancels(*this))
-            {
-                printf("alert already cancelled by %d\n", alert.nID);
-                return false;
-            }
-        }
-
-        // Add to mapAlerts
-        mapAlerts.insert(make_pair(GetHash(), *this));
-    }
-
-    printf("accepted alert %d, AppliesToMe()=%d\n", nID, AppliesToMe());
-    MainFrameRepaint();
-    return true;
-}
-
 
 
 
@@ -2561,19 +2984,16 @@ bool static AlreadyHave(CTxDB& txdb, const CInv& inv)
 
 
 // The message start string is designed to be unlikely to occur in normal data.
-// The characters are rarely used upper ascii, not valid as UTF-8, and produce
+// The characters are rarely used upper ASCII, not valid as UTF-8, and produce
 // a large 4-byte int at any alignment.
-unsigned char pchMessageStart[4] = { 0xf9, 0xbe, 0xb4, 0xd9 };
-
+unsigned char pchMessageStart[4] = { 0xe4, 0xe8, 0xe9, 0xe5 };
 
 bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
 {
-    static map<CService, vector<unsigned char> > mapReuseKey;
+    static map<CService, CPubKey> mapReuseKey;
     RandAddSeedPerfmon();
-    if (fDebug) {
-        printf("%s ", DateTimeStrFormat(GetTime()).c_str());
-        printf("received: %s (%d bytes)\n", strCommand.c_str(), vRecv.size());
-    }
+    if (fDebug)
+        printf("received: %s (%"PRIszu" bytes)\n", strCommand.c_str(), vRecv.size());
     if (mapArgs.count("-dropmessagestest") && GetRand(atoi(mapArgs["-dropmessagestest"])) == 0)
     {
         printf("dropmessagestest DROPPING RECV MESSAGE\n");
@@ -2616,6 +3036,12 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
         if (!vRecv.empty())
             vRecv >> pfrom->nStartingHeight;
 
+        if (pfrom->fInbound && addrMe.IsRoutable())
+        {
+            pfrom->addrLocal = addrMe;
+            SeenLocal(addrMe);
+        }
+
         // Disconnect if we connected to ourself
         if (nNonce == nLocalHostNonce && nNonce > 1)
         {
@@ -2643,16 +3069,15 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
         if (!pfrom->fInbound)
         {
             // Advertise our address
-            if (!fNoListen && !fUseProxy && addrLocalHost.IsRoutable() &&
-                !IsInitialBlockDownload())
+            if (!fNoListen && !IsInitialBlockDownload())
             {
-                CAddress addr(addrLocalHost);
-                addr.nTime = GetAdjustedTime();
-                pfrom->PushAddress(addr);
+                CAddress addr = GetLocalAddress(&pfrom->addr);
+                if (addr.IsRoutable())
+                    pfrom->PushAddress(addr);
             }
 
             // Get recent addresses
-            if (pfrom->nVersion >= CADDR_TIME_VERSION || addrman.size() < 1000)
+            if (pfrom->fOneShot || pfrom->nVersion >= CADDR_TIME_VERSION || addrman.size() < 1000)
             {
                 pfrom->PushMessage("getaddr");
                 pfrom->fGetAddr = true;
@@ -2668,7 +3093,8 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
 
         // Ask the first connected node for block updates
         static int nAskedForBlocks = 0;
-        if (!pfrom->fClient &&
+        if (!pfrom->fClient && !pfrom->fOneShot &&
+            (pfrom->nStartingHeight > (nBestHeight - 144)) &&
             (pfrom->nVersion < NOBLKS_VERSION_START ||
              pfrom->nVersion >= NOBLKS_VERSION_END) &&
              (nAskedForBlocks < 1 || vNodes.size() <= 1))
@@ -2693,7 +3119,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
 
         pfrom->fSuccessfullyConnected = true;
 
-        printf("version message: version %d, blocks=%d\n", pfrom->nVersion, pfrom->nStartingHeight);
+        printf("receive version message: version %d, blocks=%d, us=%s, them=%s, peer=%s\n", pfrom->nVersion, pfrom->nStartingHeight, addrMe.ToString().c_str(), addrFrom.ToString().c_str(), pfrom->addr.ToString().c_str());
 
         cPeerBlockCounts.input(pfrom->nStartingHeight);
 
@@ -2728,22 +3154,21 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
         if (vAddr.size() > 1000)
         {
             pfrom->Misbehaving(20);
-            return error("message addr size() = %d", vAddr.size());
+            return error("message addr size() = %"PRIszu"", vAddr.size());
         }
 
         // Store the new addresses
+        vector<CAddress> vAddrOk;
         int64 nNow = GetAdjustedTime();
         int64 nSince = nNow - 10 * 60;
         BOOST_FOREACH(CAddress& addr, vAddr)
         {
             if (fShutdown)
                 return true;
-            // ignore IPv6 for now, since it isn't implemented anyway
-            if (!addr.IsIPv4())
-                continue;
             if (addr.nTime <= 100000000 || addr.nTime > nNow + 10 * 60)
                 addr.nTime = nNow - 5 * 24 * 60 * 60;
             pfrom->AddAddressKnown(addr);
+            bool fReachable = IsReachable(addr);
             if (addr.nTime > nSince && !pfrom->fGetAddr && vAddr.size() <= 10 && addr.IsRoutable())
             {
                 // Relay to a limited number of other nodes
@@ -2754,7 +3179,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
                     static uint256 hashSalt;
                     if (hashSalt == 0)
                         hashSalt = GetRandHash();
-                    int64 hashAddr = addr.GetHash();
+                    uint64 hashAddr = addr.GetHash();
                     uint256 hashRand = hashSalt ^ (hashAddr<<32) ^ ((GetTime()+hashAddr)/(24*60*60));
                     hashRand = Hash(BEGIN(hashRand), END(hashRand));
                     multimap<uint256, CNode*> mapMix;
@@ -2768,15 +3193,20 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
                         hashKey = Hash(BEGIN(hashKey), END(hashKey));
                         mapMix.insert(make_pair(hashKey, pnode));
                     }
-                    int nRelayNodes = 2;
+                    int nRelayNodes = fReachable ? 2 : 1; // limited relaying of addresses outside our network(s)
                     for (multimap<uint256, CNode*>::iterator mi = mapMix.begin(); mi != mapMix.end() && nRelayNodes-- > 0; ++mi)
                         ((*mi).second)->PushAddress(addr);
                 }
             }
+            // Do not store addresses outside our network
+            if (fReachable)
+                vAddrOk.push_back(addr);
         }
-        addrman.Add(vAddr, pfrom->addr, 2 * 60 * 60);
+        addrman.Add(vAddrOk, pfrom->addr, 2 * 60 * 60);
         if (vAddr.size() < 1000)
             pfrom->fGetAddr = false;
+        if (pfrom->fOneShot)
+            pfrom->fDisconnect = true;
     }
 
 
@@ -2784,10 +3214,10 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
     {
         vector<CInv> vInv;
         vRecv >> vInv;
-        if (vInv.size() > 50000)
+        if (vInv.size() > MAX_INV_SZ)
         {
             pfrom->Misbehaving(20);
-            return error("message inv size() = %d", vInv.size());
+            return error("message inv size() = %"PRIszu"", vInv.size());
         }
 
         // find last block in inv vector
@@ -2819,7 +3249,6 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
                 // In case we are on a very long side-chain, it is possible that we already have
                 // the last block in an inv bundle sent in response to getblocks. Try to detect
                 // this situation and push another getblocks to continue.
-                std::vector<CInv> vGetData(1,inv);
                 pfrom->PushGetBlocks(mapBlockIndex[inv.hash], uint256(0));
                 if (fDebug)
                     printf("force request: %s\n", inv.ToString().c_str());
@@ -2835,17 +3264,21 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
     {
         vector<CInv> vInv;
         vRecv >> vInv;
-        if (vInv.size() > 50000)
+        if (vInv.size() > MAX_INV_SZ)
         {
             pfrom->Misbehaving(20);
-            return error("message getdata size() = %d", vInv.size());
+            return error("message getdata size() = %"PRIszu"", vInv.size());
         }
 
+        if (fDebugNet || (vInv.size() != 1))
+            printf("received getdata (%"PRIszu" invsz)\n", vInv.size());
+
         BOOST_FOREACH(const CInv& inv, vInv)
         {
             if (fShutdown)
                 return true;
-            printf("received getdata for: %s\n", inv.ToString().c_str());
+            if (fDebugNet || (vInv.size() == 1))
+                printf("received getdata for: %s\n", inv.ToString().c_str());
 
             if (inv.type == MSG_BLOCK)
             {
@@ -2860,9 +3293,6 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
                     // Trigger them to send a getblocks request for the next batch of inventory
                     if (inv.hash == pfrom->hashContinue)
                     {
-                        // Bypass PushInventory, this must send even if redundant,
-                        // and we want it right after the last block so they don't
-                        // wait for other stuff first.
                         // ppcoin: send latest proof-of-work block to allow the
                         // download node to accept as orphan (proof-of-stake 
                         // block might be rejected by stake connection check)
@@ -2876,11 +3306,24 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
             else if (inv.IsKnownType())
             {
                 // Send stream from relay memory
+                bool pushed = false;
                 {
                     LOCK(cs_mapRelay);
                     map<CInv, CDataStream>::iterator mi = mapRelay.find(inv);
-                    if (mi != mapRelay.end())
+                    if (mi != mapRelay.end()) {
                         pfrom->PushMessage(inv.GetCommand(), (*mi).second);
+                        pushed = true;
+                    }
+                }
+                if (!pushed && inv.type == MSG_TX) {
+                    LOCK(mempool.cs);
+                    if (mempool.exists(inv.hash)) {
+                        CTransaction tx = mempool.lookup(inv.hash);
+                        CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
+                        ss.reserve(1000);
+                        ss << tx;
+                        pfrom->PushMessage("tx", ss);
+                    }
                 }
             }
 
@@ -2902,35 +3345,44 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
         // Send the rest of the chain
         if (pindex)
             pindex = pindex->pnext;
-        int nLimit = 500 + locator.GetDistanceBack();
-        unsigned int nBytes = 0;
+        int nLimit = 500;
         printf("getblocks %d to %s limit %d\n", (pindex ? pindex->nHeight : -1), hashStop.ToString().substr(0,20).c_str(), nLimit);
         for (; pindex; pindex = pindex->pnext)
         {
             if (pindex->GetBlockHash() == hashStop)
             {
-                printf("  getblocks stopping at %d %s (%u bytes)\n", pindex->nHeight, pindex->GetBlockHash().ToString().substr(0,20).c_str(), nBytes);
+                printf("  getblocks stopping at %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString().substr(0,20).c_str());
                 // ppcoin: tell downloading node about the latest block if it's
                 // without risk being rejected due to stake connection check
-                if (hashStop != hashBestChain && pindex->GetBlockTime() + STAKE_MIN_AGE > pindexBest->GetBlockTime())
+                if (hashStop != hashBestChain && pindex->GetBlockTime() + nStakeMinAge > pindexBest->GetBlockTime())
                     pfrom->PushInventory(CInv(MSG_BLOCK, hashBestChain));
                 break;
             }
             pfrom->PushInventory(CInv(MSG_BLOCK, pindex->GetBlockHash()));
-            CBlock block;
-            block.ReadFromDisk(pindex, true);
-            nBytes += block.GetSerializeSize(SER_NETWORK, PROTOCOL_VERSION);
-            if (--nLimit <= 0 || nBytes >= SendBufferSize()/2)
+            if (--nLimit <= 0)
             {
                 // When this block is requested, we'll send an inv that'll make them
                 // getblocks the next batch of inventory.
-                printf("  getblocks stopping at limit %d %s (%u bytes)\n", pindex->nHeight, pindex->GetBlockHash().ToString().substr(0,20).c_str(), nBytes);
+                printf("  getblocks stopping at limit %d %s\n", pindex->nHeight, pindex->GetBlockHash().ToString().substr(0,20).c_str());
                 pfrom->hashContinue = pindex->GetBlockHash();
                 break;
             }
         }
     }
+    else if (strCommand == "checkpoint")
+    {
+        CSyncCheckpoint checkpoint;
+        vRecv >> checkpoint;
 
+        if (checkpoint.ProcessSyncCheckpoint(pfrom))
+        {
+            // Relay
+            pfrom->hashCheckpointKnown = checkpoint.hashCheckpoint;
+            LOCK(cs_vNodes);
+            BOOST_FOREACH(CNode* pnode, vNodes)
+                checkpoint.RelayTo(pnode);
+        }
+    }
 
     else if (strCommand == "getheaders")
     {
@@ -3063,6 +3515,22 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
     }
 
 
+    else if (strCommand == "mempool")
+    {
+        std::vector<uint256> vtxid;
+        mempool.queryHashes(vtxid);
+        vector<CInv> vInv;
+        for (unsigned int i = 0; i < vtxid.size(); i++) {
+            CInv inv(MSG_TX, vtxid[i]);
+            vInv.push_back(inv);
+            if (i == (MAX_INV_SZ - 1))
+                    break;
+        }
+        if (vInv.size() > 0)
+            pfrom->PushMessage("inv", vInv);
+    }
+
+
     else if (strCommand == "checkorder")
     {
         uint256 hashReply;
@@ -3137,32 +3605,31 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
         CAlert alert;
         vRecv >> alert;
 
-        if (alert.ProcessAlert())
+        uint256 alertHash = alert.GetHash();
+        if (pfrom->setKnown.count(alertHash) == 0)
         {
-            // Relay
-            pfrom->setKnown.insert(alert.GetHash());
+            if (alert.ProcessAlert())
             {
-                LOCK(cs_vNodes);
-                BOOST_FOREACH(CNode* pnode, vNodes)
-                    alert.RelayTo(pnode);
+                // Relay
+                pfrom->setKnown.insert(alertHash);
+                {
+                    LOCK(cs_vNodes);
+                    BOOST_FOREACH(CNode* pnode, vNodes)
+                        alert.RelayTo(pnode);
+                }
+            }
+            else {
+                // Small DoS penalty so peers that send us lots of
+                // duplicate/expired/invalid-signature/whatever alerts
+                // eventually get banned.
+                // This isn't a Misbehaving(100) (immediate ban) because the
+                // peer might be an older or different implementation with
+                // a different signature key, etc.
+                pfrom->Misbehaving(10);
             }
         }
     }
 
-    else if (strCommand == "checkpoint")
-    {
-        CSyncCheckpoint checkpoint;
-        vRecv >> checkpoint;
-
-        if (checkpoint.ProcessSyncCheckpoint(pfrom))
-        {
-            // Relay
-            pfrom->hashCheckpointKnown = checkpoint.hashCheckpoint;
-            LOCK(cs_vNodes);
-            BOOST_FOREACH(CNode* pnode, vNodes)
-                checkpoint.RelayTo(pnode);
-        }
-    }
 
     else
     {
@@ -3198,6 +3665,10 @@ bool ProcessMessages(CNode* pfrom)
 
     loop
     {
+        // Don't bother if send buffer is too full to respond anyway
+        if (pfrom->vSend.size() >= SendBufferSize())
+            break;
+
         // Scan for message start
         CDataStream::iterator pstart = search(vRecv.begin(), vRecv.end(), BEGIN(pchMessageStart), END(pchMessageStart));
         int nHeaderSize = vRecv.GetSerializeSize(CMessageHeader());
@@ -3211,7 +3682,7 @@ bool ProcessMessages(CNode* pfrom)
             break;
         }
         if (pstart - vRecv.begin() > 0)
-            printf("\n\nPROCESSMESSAGE SKIPPED %d BYTES\n\n", pstart - vRecv.begin());
+            printf("\n\nPROCESSMESSAGE SKIPPED %"PRIpdd" BYTES\n\n", pstart - vRecv.begin());
         vRecv.erase(vRecv.begin(), pstart);
 
         // Read header
@@ -3269,12 +3740,12 @@ bool ProcessMessages(CNode* pfrom)
         {
             if (strstr(e.what(), "end of data"))
             {
-                // Allow exceptions from underlength message on vRecv
+                // Allow exceptions from under-length message on vRecv
                 printf("ProcessMessages(%s, %u bytes) : Exception '%s' caught, normally caused by a message being shorter than its stated length\n", strCommand.c_str(), nMessageSize, e.what());
             }
             else if (strstr(e.what(), "size too large"))
             {
-                // Allow exceptions from overlong size
+                // Allow exceptions from over-long size
                 printf("ProcessMessages(%s, %u bytes) : Exception '%s' caught\n", strCommand.c_str(), nMessageSize, e.what());
             }
             else
@@ -3331,11 +3802,11 @@ bool SendMessages(CNode* pto, bool fSendTrickle)
                         pnode->setAddrKnown.clear();
 
                     // Rebroadcast our address
-                    if (!fNoListen && !fUseProxy && addrLocalHost.IsRoutable())
+                    if (!fNoListen)
                     {
-                        CAddress addr(addrLocalHost);
-                        addr.nTime = GetAdjustedTime();
-                        pnode->PushAddress(addr);
+                        CAddress addr = GetLocalAddress(&pnode->addr);
+                        if (addr.IsRoutable())
+                            pnode->PushAddress(addr);
                     }
                 }
             }
@@ -3438,15 +3909,16 @@ bool SendMessages(CNode* pto, bool fSendTrickle)
             const CInv& inv = (*pto->mapAskFor.begin()).second;
             if (!AlreadyHave(txdb, inv))
             {
-                printf("sending getdata: %s\n", inv.ToString().c_str());
+                if (fDebugNet)
+                    printf("sending getdata: %s\n", inv.ToString().c_str());
                 vGetData.push_back(inv);
                 if (vGetData.size() >= 1000)
                 {
                     pto->PushMessage("getdata", vGetData);
                     vGetData.clear();
                 }
+                mapAlreadyAskedFor[inv] = nNow;
             }
-            mapAlreadyAskedFor[inv] = nNow;
             pto->mapAskFor.erase(pto->mapAskFor.begin());
         }
         if (!vGetData.empty())
@@ -3510,39 +3982,6 @@ void SHA256Transform(void* pstate, void* pinput, const void* pinit)
         ((uint32_t*)pstate)[i] = ctx.h[i];
 }
 
-//
-// ScanHash scans nonces looking for a hash with at least some zero bits.
-// It operates on big endian data.  Caller does the byte reversing.
-// All input buffers are 16-byte aligned.  nNonce is usually preserved
-// between calls, but periodically or if nNonce is 0xffff0000 or above,
-// the block is rebuilt and nNonce starts over at zero.
-//
-unsigned int static ScanHash_CryptoPP(char* pmidstate, char* pdata, char* phash1, char* phash, unsigned int& nHashesDone)
-{
-    unsigned int& nNonce = *(unsigned int*)(pdata + 12);
-    for (;;)
-    {
-        // Crypto++ SHA-256
-        // Hash pdata using pmidstate as the starting state into
-        // preformatted buffer phash1, then hash phash1 into phash
-        nNonce++;
-        SHA256Transform(phash1, pdata, pmidstate);
-        SHA256Transform(phash, phash1, pSHA256InitState);
-
-        // Return the nonce if the hash has at least some zero bits,
-        // caller will check if it has enough to reach the target
-        if (((unsigned short*)phash)[14] == 0)
-            return nNonce;
-
-        // If nothing found after trying for a while, return -1
-        if ((nNonce & 0xffff) == 0)
-        {
-            nHashesDone = 0xffff+1;
-            return (unsigned int) -1;
-        }
-    }
-}
-
 // Some explaining would be appreciated
 class COrphan
 {
@@ -3550,16 +3989,18 @@ public:
     CTransaction* ptx;
     set<uint256> setDependsOn;
     double dPriority;
+    double dFeePerKb;
 
     COrphan(CTransaction* ptxIn)
     {
         ptx = ptxIn;
-        dPriority = 0;
+        dPriority = dFeePerKb = 0;
     }
 
     void print() const
     {
-        printf("COrphan(hash=%s, dPriority=%.1f)\n", ptx->GetHash().ToString().substr(0,10).c_str(), dPriority);
+        printf("COrphan(hash=%s, dPriority=%.1f, dFeePerKb=%.1f)\n",
+               ptx->GetHash().ToString().substr(0,10).c_str(), dPriority, dFeePerKb);
         BOOST_FOREACH(uint256 hash, setDependsOn)
             printf("   setDependsOn %s\n", hash.ToString().substr(0,10).c_str());
     }
@@ -3568,6 +4009,31 @@ public:
 
 uint64 nLastBlockTx = 0;
 uint64 nLastBlockSize = 0;
+int64 nLastCoinStakeSearchInterval = 0;
+ 
+// We want to sort transactions by priority and fee, so:
+typedef boost::tuple<double, double, CTransaction*> TxPriority;
+class TxPriorityCompare
+{
+    bool byFee;
+public:
+    TxPriorityCompare(bool _byFee) : byFee(_byFee) { }
+    bool operator()(const TxPriority& a, const TxPriority& b)
+    {
+        if (byFee)
+        {
+            if (a.get<1>() == b.get<1>())
+                return a.get<0>() < b.get<0>();
+            return a.get<1>() < b.get<1>();
+        }
+        else
+        {
+            if (a.get<0>() == b.get<0>())
+                return a.get<1>() < b.get<1>();
+            return a.get<0>() < b.get<0>();
+        }
+    }
+};
 
 // CreateNewBlock:
 //   fProofOfStake: try (best effort) to make a proof-of-stake block
@@ -3590,32 +4056,57 @@ CBlock* CreateNewBlock(CWallet* pwallet, bool fProofOfStake)
     // Add our coinbase tx as first transaction
     pblock->vtx.push_back(txNew);
 
+    // Largest block you're willing to create:
+    unsigned int nBlockMaxSize = GetArg("-blockmaxsize", MAX_BLOCK_SIZE_GEN/2);
+    // Limit to betweeen 1K and MAX_BLOCK_SIZE-1K for sanity:
+    nBlockMaxSize = std::max((unsigned int)1000, std::min((unsigned int)(MAX_BLOCK_SIZE-1000), nBlockMaxSize));
+
+    // Special compatibility rule before 20 Aug: limit size to 500,000 bytes:
+    if (GetAdjustedTime() < LOCKS_SWITCH_TIME)
+        nBlockMaxSize = std::min(nBlockMaxSize, (unsigned int)(MAX_BLOCK_SIZE_GEN));
+
+    // How much of the block should be dedicated to high-priority transactions,
+    // included regardless of the fees they pay
+    unsigned int nBlockPrioritySize = GetArg("-blockprioritysize", 27000);
+    nBlockPrioritySize = std::min(nBlockMaxSize, nBlockPrioritySize);
+
+    // Minimum block size you want to create; block will be filled with free transactions
+    // until there are no more or the block reaches this size:
+    unsigned int nBlockMinSize = GetArg("-blockminsize", 0);
+    nBlockMinSize = std::min(nBlockMaxSize, nBlockMinSize);
+
+    // Fee-per-kilobyte amount considered the same as "free"
+    // Be careful setting this: if you set it to zero then
+    // a transaction spammer can cheaply fill blocks using
+    // 1-satoshi-fee transactions. It should be set above the real
+    // cost to you of processing a transaction.
+    int64 nMinTxFee = MIN_TX_FEE;
+    if (mapArgs.count("-mintxfee"))
+        ParseMoney(mapArgs["-mintxfee"], nMinTxFee);
+
     // ppcoin: if coinstake available add coinstake tx
-    static unsigned int nLastCoinStakeCheckTime = GetAdjustedTime() - nMaxClockDrift / 2;  // only initialized at startup
+    static int64 nLastCoinStakeSearchTime = GetAdjustedTime();  // only initialized at startup
     CBlockIndex* pindexPrev = pindexBest;
 
-    if (fProofOfStake)  // attemp to find a coinstake
+    if (fProofOfStake)  // attempt to find a coinstake
     {
-        while (nLastCoinStakeCheckTime < GetAdjustedTime())
+        pblock->nBits = GetNextTargetRequired(pindexPrev, true);
+        CTransaction txCoinStake;
+        int64 nSearchTime = txCoinStake.nTime; // search to current time
+        if (nSearchTime > nLastCoinStakeSearchTime)
         {
-            pindexPrev = pindexBest;  // get best block again to avoid getting stale
-            pblock->nBits = GetNextTargetRequired(pindexPrev, true);
-            CTransaction txCoinStake;
-            {
-                static CCriticalSection cs;
-                LOCK(cs);
-                // mining may have been suspended for a while so 
-                // need to take max to satisfy the timestamp protocol
-                nLastCoinStakeCheckTime++;
-                nLastCoinStakeCheckTime = max(nLastCoinStakeCheckTime, (unsigned int) (GetAdjustedTime() - nMaxClockDrift / 2));
-                txCoinStake.nTime = nLastCoinStakeCheckTime;
-            }
-            if (pwallet->CreateCoinStake(pblock->nBits, txCoinStake))
+            if (pwallet->CreateCoinStake(*pwallet, pblock->nBits, nSearchTime-nLastCoinStakeSearchTime, txCoinStake))
             {
-                pblock->vtx.push_back(txCoinStake);
-                pblock->vtx[0].vout[0].SetEmpty();
-                break;
+                if (txCoinStake.nTime >= max(pindexPrev->GetMedianTimePast()+1, pindexPrev->GetBlockTime() - nMaxClockDrift))
+                {   // make sure coinstake would meet timestamp protocol
+                    // as it would be the same as the block timestamp
+                    pblock->vtx[0].vout[0].SetEmpty();
+                    pblock->vtx[0].nTime = txCoinStake.nTime;
+                    pblock->vtx.push_back(txCoinStake);
+                }
             }
+            nLastCoinStakeSearchInterval = nSearchTime - nLastCoinStakeSearchTime;
+            nLastCoinStakeSearchTime = nSearchTime;
         }
     }
 
@@ -3625,12 +4116,16 @@ CBlock* CreateNewBlock(CWallet* pwallet, bool fProofOfStake)
     int64 nFees = 0;
     {
         LOCK2(cs_main, mempool.cs);
+        CBlockIndex* pindexPrev = pindexBest;
         CTxDB txdb("r");
 
         // Priority order to process transactions
         list<COrphan> vOrphan; // list memory doesn't move
         map<uint256, vector<COrphan*> > mapDependers;
-        multimap<double, CTransaction*> mapPriority;
+
+        // This vector will be sorted into a priority queue:
+        vector<TxPriority> vecPriority;
+        vecPriority.reserve(mempool.mapTx.size());
         for (map<uint256, CTransaction>::iterator mi = mempool.mapTx.begin(); mi != mempool.mapTx.end(); ++mi)
         {
             CTransaction& tx = (*mi).second;
@@ -3639,6 +4134,8 @@ CBlock* CreateNewBlock(CWallet* pwallet, bool fProofOfStake)
 
             COrphan* porphan = NULL;
             double dPriority = 0;
+            int64 nTotalIn = 0;
+            bool fMissingInputs = false;
             BOOST_FOREACH(const CTxIn& txin, tx.vin)
             {
                 // Read prev transaction
@@ -3646,6 +4143,19 @@ CBlock* CreateNewBlock(CWallet* pwallet, bool fProofOfStake)
                 CTxIndex txindex;
                 if (!txPrev.ReadFromDisk(txdb, txin.prevout, txindex))
                 {
+                    // This should never happen; all transactions in the memory
+                    // pool should connect to either transactions in the chain
+                    // or other transactions in the memory pool.
+                    if (!mempool.mapTx.count(txin.prevout.hash))
+                    {
+                        printf("ERROR: mempool transaction missing input\n");
+                        if (fDebug) assert("mempool transaction missing input" == 0);
+                        fMissingInputs = true;
+                        if (porphan)
+                            vOrphan.pop_back();
+                        break;
+                    }
+
                     // Has to wait for dependencies
                     if (!porphan)
                     {
@@ -3655,34 +4165,33 @@ CBlock* CreateNewBlock(CWallet* pwallet, bool fProofOfStake)
                     }
                     mapDependers[txin.prevout.hash].push_back(porphan);
                     porphan->setDependsOn.insert(txin.prevout.hash);
+                    nTotalIn += mempool.mapTx[txin.prevout.hash].vout[txin.prevout.n].nValue;
                     continue;
                 }
                 int64 nValueIn = txPrev.vout[txin.prevout.n].nValue;
+                nTotalIn += nValueIn;
 
-                // Read block header
                 int nConf = txindex.GetDepthInMainChain();
-
                 dPriority += (double)nValueIn * nConf;
-
-                if (fDebug && GetBoolArg("-printpriority"))
-                    printf("priority     nValueIn=%-12"PRI64d" nConf=%-5d dPriority=%-20.1f\n", nValueIn, nConf, dPriority);
             }
+            if (fMissingInputs) continue;
 
             // Priority is sum(valuein * age) / txsize
-            dPriority /= ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
+            unsigned int nTxSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
+            dPriority /= nTxSize;
 
-            if (porphan)
-                porphan->dPriority = dPriority;
-            else
-                mapPriority.insert(make_pair(-dPriority, &(*mi).second));
+            // This is a more accurate fee-per-kilobyte than is used by the client code, because the
+            // client code rounds up the size to the nearest 1K. That's good, because it gives an
+            // incentive to create smaller transactions.
+            double dFeePerKb =  double(nTotalIn-tx.GetValueOut()) / (double(nTxSize)/1000.0);
 
-            if (fDebug && GetBoolArg("-printpriority"))
+            if (porphan)
             {
-                printf("priority %-20.1f %s\n%s", dPriority, tx.GetHash().ToString().substr(0,10).c_str(), tx.ToString().c_str());
-                if (porphan)
-                    porphan->print();
-                printf("\n");
+                porphan->dPriority = dPriority;
+                porphan->dFeePerKb = dFeePerKb;
             }
+            else
+                vecPriority.push_back(TxPriority(dPriority, dFeePerKb, &(*mi).second));
         }
 
         // Collect transactions into block
@@ -3690,15 +4199,24 @@ CBlock* CreateNewBlock(CWallet* pwallet, bool fProofOfStake)
         uint64 nBlockSize = 1000;
         uint64 nBlockTx = 0;
         int nBlockSigOps = 100;
-        while (!mapPriority.empty())
+        bool fSortedByFee = (nBlockPrioritySize <= 0);
+
+        TxPriorityCompare comparer(fSortedByFee);
+        std::make_heap(vecPriority.begin(), vecPriority.end(), comparer);
+
+        while (!vecPriority.empty())
         {
-            // Take highest priority transaction off priority queue
-            CTransaction& tx = *(*mapPriority.begin()).second;
-            mapPriority.erase(mapPriority.begin());
+            // Take highest priority transaction off the priority queue:
+            double dPriority = vecPriority.front().get<0>();
+            double dFeePerKb = vecPriority.front().get<1>();
+            CTransaction& tx = *(vecPriority.front().get<2>());
+
+            std::pop_heap(vecPriority.begin(), vecPriority.end(), comparer);
+            vecPriority.pop_back();
 
             // Size limits
             unsigned int nTxSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
-            if (nBlockSize + nTxSize >= MAX_BLOCK_SIZE_GEN)
+            if (nBlockSize + nTxSize >= nBlockMaxSize)
                 continue;
 
             // Legacy limits on sigOps:
@@ -3707,12 +4225,26 @@ CBlock* CreateNewBlock(CWallet* pwallet, bool fProofOfStake)
                 continue;
 
             // Timestamp limit
-            if (tx.nTime > GetAdjustedTime())
+            if (tx.nTime > GetAdjustedTime() || (pblock->IsProofOfStake() && tx.nTime > pblock->vtx[1].nTime))
                 continue;
 
             // ppcoin: simplify transaction fee - allow free = false
             int64 nMinFee = tx.GetMinFee(nBlockSize, false, GMF_BLOCK);
 
+            // Skip free transactions if we're past the minimum block size:
+            if (fSortedByFee && (dFeePerKb < nMinTxFee) && (nBlockSize + nTxSize >= nBlockMinSize))
+                continue;
+
+            // Prioritize by fee once past the priority size or we run out of high-priority
+            // transactions:
+            if (!fSortedByFee &&
+                ((nBlockSize + nTxSize >= nBlockPrioritySize) || (dPriority < COIN * 144 / 250)))
+            {
+                fSortedByFee = true;
+                comparer = TxPriorityCompare(fSortedByFee);
+                std::make_heap(vecPriority.begin(), vecPriority.end(), comparer);
+            }
+
             // Connecting shouldn't fail due to dependency on other memory pool transactions
             // because we're already processing them in order of dependency
             map<uint256, CTxIndex> mapTestPoolTmp(mapTestPool);
@@ -3741,6 +4273,12 @@ CBlock* CreateNewBlock(CWallet* pwallet, bool fProofOfStake)
             nBlockSigOps += nTxSigOps;
             nFees += nTxFees;
 
+            if (fDebug && GetBoolArg("-printpriority"))
+            {
+                printf("priority %.1f feeperkb %.1f txid %s\n",
+                       dPriority, dFeePerKb, tx.GetHash().ToString().c_str());
+            }
+
             // Add transactions that depend on this one to the priority queue
             uint256 hash = tx.GetHash();
             if (mapDependers.count(hash))
@@ -3751,7 +4289,10 @@ CBlock* CreateNewBlock(CWallet* pwallet, bool fProofOfStake)
                     {
                         porphan->setDependsOn.erase(hash);
                         if (porphan->setDependsOn.empty())
-                            mapPriority.insert(make_pair(-porphan->dPriority, porphan->ptx));
+                        {
+                            vecPriority.push_back(TxPriority(porphan->dPriority, porphan->dFeePerKb, porphan->ptx));
+                            std::push_heap(vecPriority.begin(), vecPriority.end(), comparer);
+                        }
                     }
                 }
             }
@@ -3759,20 +4300,23 @@ CBlock* CreateNewBlock(CWallet* pwallet, bool fProofOfStake)
 
         nLastBlockTx = nBlockTx;
         nLastBlockSize = nBlockSize;
-        if (fDebug && GetBoolArg("-printpriority"))
-            printf("CreateNewBlock(): total size %lu\n", nBlockSize);
 
+        if (fDebug && GetBoolArg("-printpriority"))
+            printf("CreateNewBlock(): total size %"PRI64u"\n", nBlockSize);
+
+        if (pblock->IsProofOfWork())
+            pblock->vtx[0].vout[0].nValue = GetProofOfWorkReward(pblock->nBits);
+
+        // Fill in header
+        pblock->hashPrevBlock  = pindexPrev->GetBlockHash();
+        if (pblock->IsProofOfStake())
+            pblock->nTime      = pblock->vtx[1].nTime; //same as coinstake timestamp
+        pblock->nTime          = max(pindexPrev->GetMedianTimePast()+1, pblock->GetMaxTransactionTime());
+        pblock->nTime          = max(pblock->GetBlockTime(), pindexPrev->GetBlockTime() - nMaxClockDrift);
+        if (pblock->IsProofOfWork())
+            pblock->UpdateTime(pindexPrev);
+        pblock->nNonce         = 0;
     }
-    if (pblock->IsProofOfWork())
-        pblock->vtx[0].vout[0].nValue = GetProofOfWorkReward(pblock->nBits);
-
-    // Fill in header
-    pblock->hashPrevBlock  = pindexPrev->GetBlockHash();
-    pblock->hashMerkleRoot = pblock->BuildMerkleTree();
-    pblock->nTime          = max(pindexPrev->GetMedianTimePast()+1, pblock->GetMaxTransactionTime());
-    pblock->nTime          = max(pblock->GetBlockTime(), pindexPrev->GetBlockTime() - nMaxClockDrift);
-    pblock->UpdateTime(pindexPrev);
-    pblock->nNonce         = 0;
 
     return pblock.release();
 }
@@ -3788,7 +4332,8 @@ void IncrementExtraNonce(CBlock* pblock, CBlockIndex* pindexPrev, unsigned int&
         hashPrevBlock = pblock->hashPrevBlock;
     }
     ++nExtraNonce;
-    pblock->vtx[0].vin[0].scriptSig = (CScript() << pblock->nTime << CBigNum(nExtraNonce)) + COINBASE_FLAGS;
+    unsigned int nHeight = pindexPrev->nHeight+1; // Height first in coinbase required for block.version=2
+    pblock->vtx[0].vin[0].scriptSig = (CScript() << nHeight << CBigNum(nExtraNonce)) + COINBASE_FLAGS;
     assert(pblock->vtx[0].vin[0].scriptSig.size() <= 100);
 
     pblock->hashMerkleRoot = pblock->BuildMerkleTree();
@@ -3798,7 +4343,7 @@ void IncrementExtraNonce(CBlock* pblock, CBlockIndex* pindexPrev, unsigned int&
 void FormatHashBuffers(CBlock* pblock, char* pmidstate, char* pdata, char* phash1)
 {
     //
-    // Prebuild hash buffers
+    // Pre-build hash buffers
     //
     struct
     {
@@ -3853,7 +4398,6 @@ bool CheckWork(CBlock* pblock, CWallet& wallet, CReserveKey& reservekey)
     printf("BitcoinMiner:\n");
     printf("new block found  \n  hash: %s  \ntarget: %s\n", hash.GetHex().c_str(), hashTarget.GetHex().c_str());
     pblock->print();
-    printf("%s ", DateTimeStrFormat(GetTime()).c_str());
     printf("generated %s\n", FormatMoney(pblock->vtx[0].vout[0].nValue).c_str());
 
     // Found a solution
@@ -3879,22 +4423,18 @@ bool CheckWork(CBlock* pblock, CWallet& wallet, CReserveKey& reservekey)
     return true;
 }
 
-void static ThreadBitcoinMiner(void* parg);
-
-static bool fGenerateBitcoins = false;
-static bool fLimitProcessors = false;
-static int nLimitProcessors = -1;
-
 void BitcoinMiner(CWallet *pwallet, bool fProofOfStake)
 {
-    printf("CPUMiner started for proof-of-%s\n", fProofOfStake? "stake" : "work");
     SetThreadPriority(THREAD_PRIORITY_LOWEST);
 
+    // Make this thread recognisable as the mining thread
+    RenameThread("bitcoin-miner");
+
     // Each thread has its own key and counter
     CReserveKey reservekey(pwallet);
     unsigned int nExtraNonce = 0;
 
-    while (fGenerateBitcoins || fProofOfStake)
+    while (fProofOfStake)
     {
         if (fShutdown)
             return;
@@ -3903,7 +4443,7 @@ void BitcoinMiner(CWallet *pwallet, bool fProofOfStake)
             Sleep(1000);
             if (fShutdown)
                 return;
-            if ((!fGenerateBitcoins) && !fProofOfStake)
+            if (!fProofOfStake)
                 return;
         }
 
@@ -3917,18 +4457,16 @@ void BitcoinMiner(CWallet *pwallet, bool fProofOfStake)
         //
         // Create new block
         //
-        unsigned int nTransactionsUpdatedLast = nTransactionsUpdated;
         CBlockIndex* pindexPrev = pindexBest;
 
         auto_ptr<CBlock> pblock(CreateNewBlock(pwallet, fProofOfStake));
         if (!pblock.get())
             return;
-
         IncrementExtraNonce(pblock.get(), pindexPrev, nExtraNonce);
 
-        // ppcoin: if proof-of-stake block found then process block
         if (fProofOfStake)
         {
+            // ppcoin: if proof-of-stake block found then process block
             if (pblock->IsProofOfStake())
             {
                 if (!pblock->SignBlock(*pwalletMain))
@@ -3937,7 +4475,7 @@ void BitcoinMiner(CWallet *pwallet, bool fProofOfStake)
                     continue;
                 }
                 strMintWarning = "";
-                printf("CPUMiner : proof-of-stake block found %s\n", pblock->GetHash().ToString().c_str()); 
+                printf("StakeMiner : proof-of-stake block found %s\n", pblock->GetHash().ToString().c_str()); 
                 SetThreadPriority(THREAD_PRIORITY_NORMAL);
                 CheckWork(pblock.get(), *pwalletMain, reservekey);
                 SetThreadPriority(THREAD_PRIORITY_LOWEST);
@@ -3945,166 +4483,6 @@ void BitcoinMiner(CWallet *pwallet, bool fProofOfStake)
             Sleep(500);
             continue;
         }
-
-        printf("Running BitcoinMiner with %d transactions in block\n", pblock->vtx.size());
-
-
-        //
-        // Prebuild hash buffers
-        //
-        char pmidstatebuf[32+16]; char* pmidstate = alignup<16>(pmidstatebuf);
-        char pdatabuf[128+16];    char* pdata     = alignup<16>(pdatabuf);
-        char phash1buf[64+16];    char* phash1    = alignup<16>(phash1buf);
-
-        FormatHashBuffers(pblock.get(), pmidstate, pdata, phash1);
-
-        unsigned int& nBlockTime = *(unsigned int*)(pdata + 64 + 4);
-        unsigned int& nBlockNonce = *(unsigned int*)(pdata + 64 + 12);
-
-
-        //
-        // Search
-        //
-        int64 nStart = GetTime();
-        uint256 hashTarget = CBigNum().SetCompact(pblock->nBits).getuint256();
-        uint256 hashbuf[2];
-        uint256& hash = *alignup<16>(hashbuf);
-        loop
-        {
-            unsigned int nHashesDone = 0;
-            unsigned int nNonceFound;
-
-            // Crypto++ SHA-256
-            nNonceFound = ScanHash_CryptoPP(pmidstate, pdata + 64, phash1,
-                                            (char*)&hash, nHashesDone);
-
-            // Check if something found
-            if (nNonceFound != (unsigned int) -1)
-            {
-                for (unsigned int i = 0; i < sizeof(hash)/4; i++)
-                    ((unsigned int*)&hash)[i] = ByteReverse(((unsigned int*)&hash)[i]);
-
-                if (hash <= hashTarget)
-                {
-                    // Found a solution
-                    pblock->nNonce = ByteReverse(nNonceFound);
-                    assert(hash == pblock->GetHash());
-                    if (!pblock->SignBlock(*pwalletMain))
-                    {
-                        strMintWarning = strMintMessage;
-                        break;
-                    }
-                    strMintWarning = "";
-                    SetThreadPriority(THREAD_PRIORITY_NORMAL);
-                    CheckWork(pblock.get(), *pwalletMain, reservekey);
-                    SetThreadPriority(THREAD_PRIORITY_LOWEST);
-                    break;
-                }
-            }
-
-            // Meter hashes/sec
-            static int64 nHashCounter;
-            if (nHPSTimerStart == 0)
-            {
-                nHPSTimerStart = GetTimeMillis();
-                nHashCounter = 0;
-            }
-            else
-                nHashCounter += nHashesDone;
-            if (GetTimeMillis() - nHPSTimerStart > 4000)
-            {
-                static CCriticalSection cs;
-                {
-                    LOCK(cs);
-                    if (GetTimeMillis() - nHPSTimerStart > 4000)
-                    {
-                        dHashesPerSec = 1000.0 * nHashCounter / (GetTimeMillis() - nHPSTimerStart);
-                        nHPSTimerStart = GetTimeMillis();
-                        nHashCounter = 0;
-                        static int64 nLogTime;
-                        if (GetTime() - nLogTime > 30 * 60)
-                        {
-                            nLogTime = GetTime();
-                            printf("%s ", DateTimeStrFormat(GetTime()).c_str());
-                            printf("hashmeter %3d CPUs %6.0f khash/s\n", vnThreadsRunning[THREAD_MINER], dHashesPerSec/1000.0);
-                        }
-                    }
-                }
-            }
-
-            // Check for stop or if block needs to be rebuilt
-            if (fShutdown)
-                return;
-            if (!fGenerateBitcoins)
-                return;
-            if (fLimitProcessors && vnThreadsRunning[THREAD_MINER] > nLimitProcessors)
-                return;
-            if (vNodes.empty())
-                break;
-            if (nBlockNonce >= 0xffff0000)
-                break;
-            if (nTransactionsUpdated != nTransactionsUpdatedLast && GetTime() - nStart > 60)
-                break;
-            if (pindexPrev != pindexBest)
-                break;
-
-            // Update nTime every few seconds
-            pblock->nTime = max(pindexPrev->GetMedianTimePast()+1, pblock->GetMaxTransactionTime());
-            pblock->nTime = max(pblock->GetBlockTime(), pindexPrev->GetBlockTime() - nMaxClockDrift);
-            pblock->UpdateTime(pindexPrev);
-            nBlockTime = ByteReverse(pblock->nTime);
-            if (pblock->GetBlockTime() >= (int64)pblock->vtx[0].nTime + nMaxClockDrift)
-                break;  // need to update coinbase timestamp
-        }
     }
 }
 
-void static ThreadBitcoinMiner(void* parg)
-{
-    CWallet* pwallet = (CWallet*)parg;
-    try
-    {
-        vnThreadsRunning[THREAD_MINER]++;
-        BitcoinMiner(pwallet, false);
-        vnThreadsRunning[THREAD_MINER]--;
-    }
-    catch (std::exception& e) {
-        vnThreadsRunning[THREAD_MINER]--;
-        PrintException(&e, "ThreadBitcoinMiner()");
-    } catch (...) {
-        vnThreadsRunning[THREAD_MINER]--;
-        PrintException(NULL, "ThreadBitcoinMiner()");
-    }
-    nHPSTimerStart = 0;
-    if (vnThreadsRunning[THREAD_MINER] == 0)
-        dHashesPerSec = 0;
-    printf("ThreadBitcoinMiner exiting, %d threads remaining\n", vnThreadsRunning[THREAD_MINER]);
-}
-
-
-void GenerateBitcoins(bool fGenerate, CWallet* pwallet)
-{
-    fGenerateBitcoins = fGenerate;
-    nLimitProcessors = GetArg("-genproclimit", -1);
-    if (nLimitProcessors == 0)
-        fGenerateBitcoins = false;
-    fLimitProcessors = (nLimitProcessors != -1);
-
-    if (fGenerate)
-    {
-        int nProcessors = boost::thread::hardware_concurrency();
-        printf("%d processors\n", nProcessors);
-        if (nProcessors < 1)
-            nProcessors = 1;
-        if (fLimitProcessors && nProcessors > nLimitProcessors)
-            nProcessors = nLimitProcessors;
-        int nAddThreads = nProcessors - vnThreadsRunning[THREAD_MINER];
-        printf("Starting %d BitcoinMiner threads\n", nAddThreads);
-        for (int i = 0; i < nAddThreads; i++)
-        {
-            if (!CreateThread(ThreadBitcoinMiner, pwallet))
-                printf("Error: CreateThread(ThreadBitcoinMiner) failed\n");
-            Sleep(10);
-        }
-    }
-}