Merge branch '1.14-branding'

6 files changed, 367 insertions, 315 deletions

diff --git a/src/primitives/block.cpp b/src/primitives/block.cpp
index 7bd64d77c..1df912d35 100644
--- a/src/primitives/block.cpp
+++ b/src/primitives/block.cpp
@@ -1,5 +1,5 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2014 The Bitcoin Core developers
+// Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -15,125 +15,36 @@ void CBlockHeader::SetAuxpow (CAuxPow* apow)
     if (apow)
     {
         auxpow.reset(apow);
-        nVersion.SetAuxpow(true);
+        SetAuxpowFlag(true);
     } else
     {
         auxpow.reset();
-        nVersion.SetAuxpow(false);
+        SetAuxpowFlag(false);
     }
 }
 
-uint256 CBlock::BuildMerkleTree(bool* fMutated) const
-{
-    /* WARNING! If you're reading this because you're learning about crypto
-       and/or designing a new system that will use merkle trees, keep in mind
-       that the following merkle tree algorithm has a serious flaw related to
-       duplicate txids, resulting in a vulnerability (CVE-2012-2459).
-
-       The reason is that if the number of hashes in the list at a given time
-       is odd, the last one is duplicated before computing the next level (which
-       is unusual in Merkle trees). This results in certain sequences of
-       transactions leading to the same merkle root. For example, these two
-       trees:
-
-                    A               A
-                  /  \            /   \
-                B     C         B       C
-               / \    |        / \     / \
-              D   E   F       D   E   F   F
-             / \ / \ / \     / \ / \ / \ / \
-             1 2 3 4 5 6     1 2 3 4 5 6 5 6
-
-       for transaction lists [1,2,3,4,5,6] and [1,2,3,4,5,6,5,6] (where 5 and
-       6 are repeated) result in the same root hash A (because the hash of both
-       of (F) and (F,F) is C).
-
-       The vulnerability results from being able to send a block with such a
-       transaction list, with the same merkle root, and the same block hash as
-       the original without duplication, resulting in failed validation. If the
-       receiving node proceeds to mark that block as permanently invalid
-       however, it will fail to accept further unmodified (and thus potentially
-       valid) versions of the same block. We defend against this by detecting
-       the case where we would hash two identical hashes at the end of the list
-       together, and treating that identically to the block having an invalid
-       merkle root. Assuming no double-SHA256 collisions, this will detect all
-       known ways of changing the transactions without affecting the merkle
-       root.
-    */
-    vMerkleTree.clear();
-    vMerkleTree.reserve(vtx.size() * 2 + 16); // Safe upper bound for the number of total nodes.
-    for (std::vector<CTransaction>::const_iterator it(vtx.begin()); it != vtx.end(); ++it)
-        vMerkleTree.push_back(it->GetHash());
-    int j = 0;
-    bool mutated = false;
-    for (int nSize = vtx.size(); nSize > 1; nSize = (nSize + 1) / 2)
-    {
-        for (int i = 0; i < nSize; i += 2)
-        {
-            int i2 = std::min(i+1, nSize-1);
-            if (i2 == i + 1 && i2 + 1 == nSize && vMerkleTree[j+i] == vMerkleTree[j+i2]) {
-                // Two identical hashes at the end of the list at a particular level.
-                mutated = true;
-            }
-            vMerkleTree.push_back(Hash(BEGIN(vMerkleTree[j+i]),  END(vMerkleTree[j+i]),
-                                       BEGIN(vMerkleTree[j+i2]), END(vMerkleTree[j+i2])));
-        }
-        j += nSize;
-    }
-    if (fMutated) {
-        *fMutated = mutated;
-    }
-    return (vMerkleTree.empty() ? uint256() : vMerkleTree.back());
-}
-
-std::vector<uint256> CBlock::GetMerkleBranch(int nIndex) const
-{
-    if (vMerkleTree.empty())
-        BuildMerkleTree();
-    std::vector<uint256> vMerkleBranch;
-    int j = 0;
-    for (int nSize = vtx.size(); nSize > 1; nSize = (nSize + 1) / 2)
-    {
-        int i = std::min(nIndex^1, nSize-1);
-        vMerkleBranch.push_back(vMerkleTree[j+i]);
-        nIndex >>= 1;
-        j += nSize;
-    }
-    return vMerkleBranch;
-}
-
-uint256 CBlock::CheckMerkleBranch(uint256 hash, const std::vector<uint256>& vMerkleBranch, int nIndex)
-{
-    if (nIndex == -1)
-        return uint256();
-    for (std::vector<uint256>::const_iterator it(vMerkleBranch.begin()); it != vMerkleBranch.end(); ++it)
-    {
-        if (nIndex & 1)
-            hash = Hash(BEGIN(*it), END(*it), BEGIN(hash), END(hash));
-        else
-            hash = Hash(BEGIN(hash), END(hash), BEGIN(*it), END(*it));
-        nIndex >>= 1;
-    }
-    return hash;
-}
-
 std::string CBlock::ToString() const
 {
     std::stringstream s;
-    s << strprintf("CBlock(hash=%s, ver=%d, hashPrevBlock=%s, hashMerkleRoot=%s, nTime=%u, nBits=%08x, nNonce=%u, vtx=%u)\n",
+    s << strprintf("CBlock(hash=%s, ver=0x%08x, hashPrevBlock=%s, hashMerkleRoot=%s, nTime=%u, nBits=%08x, nNonce=%u, vtx=%u)\n",
         GetHash().ToString(),
-        nVersion.GetFullVersion(),
+        nVersion,
         hashPrevBlock.ToString(),
         hashMerkleRoot.ToString(),
         nTime, nBits, nNonce,
         vtx.size());
     for (unsigned int i = 0; i < vtx.size(); i++)
     {
-        s << "  " << vtx[i].ToString() << "\n";
+        s << "  " << vtx[i]->ToString() << "\n";
     }
-    s << "  vMerkleTree: ";
-    for (unsigned int i = 0; i < vMerkleTree.size(); i++)
-        s << " " << vMerkleTree[i].ToString();
-    s << "\n";
     return s.str();
 }
+
+int64_t GetBlockWeight(const CBlock& block)
+{
+    // This implements the weight = (stripped_size * 4) + witness_size formula,
+    // using only serialization with and without witness data. As witness_size
+    // is equal to total_size - stripped_size, this formula is identical to:
+    // weight = (stripped_size * 3) + total_size.
+    return ::GetSerializeSize(block, SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) * (WITNESS_SCALE_FACTOR - 1) + ::GetSerializeSize(block, SER_NETWORK, PROTOCOL_VERSION);
+}
diff --git a/src/primitives/block.h b/src/primitives/block.h
index d59ac4427..dcde500ab 100644
--- a/src/primitives/block.h
+++ b/src/primitives/block.h
@@ -1,5 +1,5 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2013 The Bitcoin Core developers
+// Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -35,11 +35,11 @@ public:
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+    inline void SerializationOp(Stream& s, Operation ser_action) {
         READWRITE(*(CPureBlockHeader*)this);
-        nVersion = this->nVersion;
 
-        if (this->nVersion.IsAuxpow()) {
+        if (this->IsAuxpow())
+        {
             if (ser_action.ForRead())
                 auxpow.reset(new CAuxPow());
             assert(auxpow);
@@ -54,11 +54,6 @@ public:
         auxpow.reset();
     }
 
-    int64_t GetBlockTime() const
-    {
-        return (int64_t)nTime;
-    }
-
     /**
      * Set the block's auxpow (or unset it).  This takes care of updating
      * the version accordingly.
@@ -72,10 +67,10 @@ class CBlock : public CBlockHeader
 {
 public:
     // network and disk
-    std::vector<CTransaction> vtx;
+    std::vector<CTransactionRef> vtx;
 
     // memory only
-    mutable std::vector<uint256> vMerkleTree;
+    mutable bool fChecked;
 
     CBlock()
     {
@@ -91,7 +86,7 @@ public:
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+    inline void SerializationOp(Stream& s, Operation ser_action) {
         READWRITE(*(CBlockHeader*)this);
         READWRITE(vtx);
     }
@@ -100,7 +95,7 @@ public:
     {
         CBlockHeader::SetNull();
         vtx.clear();
-        vMerkleTree.clear();
+        fChecked = false;
     }
 
     CBlockHeader GetBlockHeader() const
@@ -127,7 +122,6 @@ public:
     std::string ToString() const;
 };
 
-
 /** Describes a place in the block chain to another node such that if the
  * other node doesn't have the same branch, it can find a recent common trunk.
  * The further back it is, the further before the fork it may be.
@@ -146,8 +140,9 @@ struct CBlockLocator
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
-        if (!(nType & SER_GETHASH))
+    inline void SerializationOp(Stream& s, Operation ser_action) {
+        int nVersion = s.GetVersion();
+        if (!(s.GetType() & SER_GETHASH))
             READWRITE(nVersion);
         READWRITE(vHave);
     }
@@ -163,4 +158,7 @@ struct CBlockLocator
     }
 };
 
+/** Compute the consensus-critical block weight (see BIP 141). */
+int64_t GetBlockWeight(const CBlock& tx);
+
 #endif // BITCOIN_PRIMITIVES_BLOCK_H
diff --git a/src/primitives/pureheader.cpp b/src/primitives/pureheader.cpp
index 94f14499b..9a339bf1f 100644
--- a/src/primitives/pureheader.cpp
+++ b/src/primitives/pureheader.cpp
@@ -10,6 +10,13 @@
 #include "hash.h"
 #include "utilstrencodings.h"
 
+void CPureBlockHeader::SetBaseVersion(int32_t nBaseVersion, int32_t nChainId)
+{
+    assert(nBaseVersion >= 1 && nBaseVersion < VERSION_AUXPOW);
+    assert(!IsAuxpow());
+    nVersion = nBaseVersion | (nChainId * VERSION_CHAIN_START);
+}
+
 uint256 CPureBlockHeader::GetHash() const
 {
     return SerializeHash(*this);
diff --git a/src/primitives/pureheader.h b/src/primitives/pureheader.h
index 25f1ce98b..841743632 100644
--- a/src/primitives/pureheader.h
+++ b/src/primitives/pureheader.h
@@ -10,24 +10,30 @@
 #include "uint256.h"
 
 /**
- * Encapsulate a block version.  This takes care of building it up
- * from a base version, the modifier flags (like auxpow) and
- * also the auxpow chain ID.
+ * A block header without auxpow information.  This "intermediate step"
+ * in constructing the full header is useful, because it breaks the cyclic
+ * dependency between auxpow (referencing a parent block header) and
+ * the block header (referencing an auxpow).  The parent block header
+ * does not have auxpow itself, so it is a pure header.
  */
-class CBlockVersion
+class CPureBlockHeader
 {
-private:
+public:
     /* Modifiers to the version.  */
     static const int32_t VERSION_AUXPOW = (1 << 8);
 
     /** Bits above are reserved for the auxpow chain ID.  */
     static const int32_t VERSION_CHAIN_START = (1 << 16);
 
-    /** The version as integer.  Should not be accessed directly.  */
-    int nVersion;
+    // header
+    int32_t nVersion;
+    uint256 hashPrevBlock;
+    uint256 hashMerkleRoot;
+    uint32_t nTime;
+    uint32_t nBits;
+    uint32_t nNonce;
 
-public:
-    inline CBlockVersion()
+    CPureBlockHeader()
     {
         SetNull();
     }
@@ -35,17 +41,69 @@ public:
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion)
+    inline void SerializationOp(Stream& s, Operation ser_action)
     {
         READWRITE(this->nVersion);
+        READWRITE(hashPrevBlock);
+        READWRITE(hashMerkleRoot);
+        READWRITE(nTime);
+        READWRITE(nBits);
+        READWRITE(nNonce);
     }
 
-    inline void SetNull()
+    void SetNull()
     {
         nVersion = 0;
+        hashPrevBlock.SetNull();
+        hashMerkleRoot.SetNull();
+        nTime = 0;
+        nBits = 0;
+        nNonce = 0;
+    }
+
+    bool IsNull() const
+    {
+        return (nBits == 0);
+    }
+
+    uint256 GetHash() const;
+
+    uint256 GetPoWHash() const;
+
+    int64_t GetBlockTime() const
+    {
+        return (int64_t)nTime;
+    }
+
+    /* Below are methods to interpret the version with respect to
+       auxpow data and chain ID.  This used to be in the CBlockVersion
+       class, but was moved here when we switched back to nVersion being
+       a pure int member as preparation to undoing the "abuse" and
+       allowing BIP9 to work.  */
+
+    /**
+     * Extract the base version (without modifiers and chain ID).
+     * @return The base version./
+     */
+    inline int32_t GetBaseVersion() const
+    {
+        return GetBaseVersion(nVersion);
+    }
+    static inline int32_t GetBaseVersion(int32_t ver)
+    {
+        return ver % VERSION_AUXPOW;
     }
 
     /**
+     * Set the base version (apart from chain ID and auxpow flag) to
+     * the one given.  This should only be called when auxpow is not yet
+     * set, to initialise a block!
+     * @param nBaseVersion The base version.
+     * @param nChainId The auxpow chain ID.
+     */
+    void SetBaseVersion(int32_t nBaseVersion, int32_t nChainId);
+
+    /**
      * Extract the chain ID.
      * @return The chain ID encoded in the version.
      */
@@ -65,27 +123,8 @@ public:
     }
 
     /**
-     * Extract the full version.  Used for RPC results and debug prints.
-     * @return The full version.
-     */
-    inline int32_t GetFullVersion() const
-    {
-        return nVersion;
-    }
-
-    /**
-     * Set the genesis block version.  This must be a literal write
-     * through, to get the correct historic version.
-     * @param nGenesisVersion The version to set.
-     */
-    inline void SetGenesisVersion(int32_t nGenesisVersion)
-    {
-        nVersion = nGenesisVersion;
-    }
-
-    /**
      * Check if the auxpow flag is set in the version.
-     * @return True iff this block version is marked as auxpow.
+     * @return True if this block version is marked as auxpow.
      */
     inline bool IsAuxpow() const
     {
@@ -96,7 +135,7 @@ public:
      * Set the auxpow flag.  This is used for testing.
      * @param auxpow Whether to mark auxpow as true.
      */
-    inline void SetAuxpow(bool auxpow)
+    inline void SetAuxpowFlag(bool auxpow)
     {
         if (auxpow)
             nVersion |= VERSION_AUXPOW;
@@ -111,91 +150,9 @@ public:
     inline bool IsLegacy() const
     {
         return nVersion == 1
+            // Dogecoin: We have a random v2 block with no AuxPoW, treat as legacy
             || (nVersion == 2 && GetChainId() == 0);
     }
-
-    CBlockVersion& operator=(const CBlockVersion& other)
-    {
-        nVersion = other.nVersion;
-        return *this;
-    }
-
-    CBlockVersion& operator=(const int nBaseVersion)
-    {
-        nVersion = (nBaseVersion & 0x000000ff) | (nVersion & 0xffffff00);
-        return *this;
-    }
-
-    operator int() { return nVersion & 0x000000ff; }
-    friend inline bool operator==(const CBlockVersion a, const int b) { return (a.nVersion & 0x000000ff) == b; }
-    friend inline bool operator!=(const CBlockVersion a, const int b) { return (a.nVersion & 0x000000ff) != b; }
-    friend inline bool operator>(const CBlockVersion a, const int b) { return (a.nVersion & 0x000000ff) > b; }
-    friend inline bool operator<(const CBlockVersion a, const int b) { return (a.nVersion & 0x000000ff) < b; }
-    friend inline bool operator>=(const CBlockVersion a, const int b) { return (a.nVersion & 0x000000ff) >= b; }
-    friend inline bool operator<=(const CBlockVersion a, const int b) { return (a.nVersion & 0x000000ff) <= b; }
-};
-
-/**
- * A block header without auxpow information.  This "intermediate step"
- * in constructing the full header is useful, because it breaks the cyclic
- * dependency between auxpow (referencing a parent block header) and
- * the block header (referencing an auxpow).  The parent block header
- * does not have auxpow itself, so it is a pure header.
- */
-class CPureBlockHeader
-{
-public:
-    // header
-    static const int32_t CURRENT_VERSION = 3;
-    CBlockVersion nVersion;
-    uint256 hashPrevBlock;
-    uint256 hashMerkleRoot;
-    uint32_t nTime;
-    uint32_t nBits;
-    uint32_t nNonce;
-
-    CPureBlockHeader()
-    {
-        SetNull();
-    }
-
-    ADD_SERIALIZE_METHODS;
-
-    template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion)
-    {
-        READWRITE(this->nVersion);
-        nVersion = this->nVersion;
-        READWRITE(hashPrevBlock);
-        READWRITE(hashMerkleRoot);
-        READWRITE(nTime);
-        READWRITE(nBits);
-        READWRITE(nNonce);
-    }
-
-    void SetNull()
-    {
-        nVersion.SetNull();
-        hashPrevBlock.SetNull();
-        hashMerkleRoot.SetNull();
-        nTime = 0;
-        nBits = 0;
-        nNonce = 0;
-    }
-
-    bool IsNull() const
-    {
-        return (nBits == 0);
-    }
-
-    uint256 GetHash() const;
-
-    uint256 GetPoWHash() const;
-
-    int64_t GetBlockTime() const
-    {
-        return (int64_t)nTime;
-    }
 };
 
 #endif // BITCOIN_PRIMITIVES_PUREHEADER_H
diff --git a/src/primitives/transaction.cpp b/src/primitives/transaction.cpp
index 606dbea79..28ef1fb46 100644
--- a/src/primitives/transaction.cpp
+++ b/src/primitives/transaction.cpp
@@ -1,5 +1,5 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2014 The Bitcoin Core developers
+// Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -36,8 +36,8 @@ std::string CTxIn::ToString() const
     if (prevout.IsNull())
         str += strprintf(", coinbase %s", HexStr(scriptSig));
     else
-        str += strprintf(", scriptSig=%s", scriptSig.ToString().substr(0,24));
-    if (nSequence != std::numeric_limits<unsigned int>::max())
+        str += strprintf(", scriptSig=%s", HexStr(scriptSig).substr(0, 24));
+    if (nSequence != SEQUENCE_FINAL)
         str += strprintf(", nSequence=%u", nSequence);
     str += ")";
     return str;
@@ -49,14 +49,9 @@ CTxOut::CTxOut(const CAmount& nValueIn, CScript scriptPubKeyIn)
     scriptPubKey = scriptPubKeyIn;
 }
 
-uint256 CTxOut::GetHash() const
-{
-    return SerializeHash(*this);
-}
-
 std::string CTxOut::ToString() const
 {
-    return strprintf("CTxOut(nValue=%d.%08d, scriptPubKey=%s)", nValue / COIN, nValue % COIN, scriptPubKey.ToString().substr(0,30));
+    return strprintf("CTxOut(nValue=%d.%08d, scriptPubKey=%s)", nValue / COIN, nValue % COIN, HexStr(scriptPubKey).substr(0, 30));
 }
 
 CMutableTransaction::CMutableTransaction() : nVersion(CTransaction::CURRENT_VERSION), nLockTime(0) {}
@@ -64,28 +59,26 @@ CMutableTransaction::CMutableTransaction(const CTransaction& tx) : nVersion(tx.n
 
 uint256 CMutableTransaction::GetHash() const
 {
-    return SerializeHash(*this);
+    return SerializeHash(*this, SER_GETHASH, SERIALIZE_TRANSACTION_NO_WITNESS);
 }
 
-void CTransaction::UpdateHash() const
+uint256 CTransaction::ComputeHash() const
 {
-    *const_cast<uint256*>(&hash) = SerializeHash(*this);
+    return SerializeHash(*this, SER_GETHASH, SERIALIZE_TRANSACTION_NO_WITNESS);
 }
 
-CTransaction::CTransaction() : nVersion(CTransaction::CURRENT_VERSION), vin(), vout(), nLockTime(0) { }
-
-CTransaction::CTransaction(const CMutableTransaction &tx) : nVersion(tx.nVersion), vin(tx.vin), vout(tx.vout), nLockTime(tx.nLockTime) {
-    UpdateHash();
+uint256 CTransaction::GetWitnessHash() const
+{
+    if (!HasWitness()) {
+        return GetHash();
+    }
+    return SerializeHash(*this, SER_GETHASH, 0);
 }
 
-CTransaction& CTransaction::operator=(const CTransaction &tx) {
-    *const_cast<int*>(&nVersion) = tx.nVersion;
-    *const_cast<std::vector<CTxIn>*>(&vin) = tx.vin;
-    *const_cast<std::vector<CTxOut>*>(&vout) = tx.vout;
-    *const_cast<unsigned int*>(&nLockTime) = tx.nLockTime;
-    *const_cast<uint256*>(&hash) = tx.hash;
-    return *this;
-}
+/* For backward compatibility, the hash is initialized to 0. TODO: remove the need for this default constructor entirely. */
+CTransaction::CTransaction() : nVersion(CTransaction::CURRENT_VERSION), vin(), vout(), nLockTime(0), hash() {}
+CTransaction::CTransaction(const CMutableTransaction &tx) : nVersion(tx.nVersion), vin(tx.vin), vout(tx.vout), nLockTime(tx.nLockTime), hash(ComputeHash()) {}
+CTransaction::CTransaction(CMutableTransaction &&tx) : nVersion(tx.nVersion), vin(std::move(tx.vin)), vout(std::move(tx.vout)), nLockTime(tx.nLockTime), hash(ComputeHash()) {}
 
 CAmount CTransaction::GetValueOut() const
 {
@@ -94,7 +87,7 @@ CAmount CTransaction::GetValueOut() const
     {
         nValueOut += it->nValue;
         if (!MoneyRange(it->nValue) || !MoneyRange(nValueOut))
-            throw std::runtime_error("CTransaction::GetValueOut(): value out of range");
+            throw std::runtime_error(std::string(__func__) + ": value out of range");
     }
     return nValueOut;
 }
@@ -115,7 +108,7 @@ unsigned int CTransaction::CalculateModifiedSize(unsigned int nTxSize) const
     // Providing any more cleanup incentive than making additional inputs free would
     // risk encouraging people to create junk outputs to redeem later.
     if (nTxSize == 0)
-        nTxSize = ::GetSerializeSize(*this, SER_NETWORK, PROTOCOL_VERSION);
+        nTxSize = (GetTransactionWeight(*this) + WITNESS_SCALE_FACTOR - 1) / WITNESS_SCALE_FACTOR;
     for (std::vector<CTxIn>::const_iterator it(vin.begin()); it != vin.end(); ++it)
     {
         unsigned int offset = 41U + std::min(110U, (unsigned int)it->scriptSig.size());
@@ -125,6 +118,11 @@ unsigned int CTransaction::CalculateModifiedSize(unsigned int nTxSize) const
     return nTxSize;
 }
 
+unsigned int CTransaction::GetTotalSize() const
+{
+    return ::GetSerializeSize(*this, SER_NETWORK, PROTOCOL_VERSION);
+}
+
 std::string CTransaction::ToString() const
 {
     std::string str;
@@ -136,7 +134,14 @@ std::string CTransaction::ToString() const
         nLockTime);
     for (unsigned int i = 0; i < vin.size(); i++)
         str += "    " + vin[i].ToString() + "\n";
+    for (unsigned int i = 0; i < vin.size(); i++)
+        str += "    " + vin[i].scriptWitness.ToString() + "\n";
     for (unsigned int i = 0; i < vout.size(); i++)
         str += "    " + vout[i].ToString() + "\n";
     return str;
 }
+
+int64_t GetTransactionWeight(const CTransaction& tx)
+{
+    return ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) * (WITNESS_SCALE_FACTOR -1) + ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
+}
diff --git a/src/primitives/transaction.h b/src/primitives/transaction.h
index 15b31c251..ceb8f6ace 100644
--- a/src/primitives/transaction.h
+++ b/src/primitives/transaction.h
@@ -1,5 +1,5 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2014 The Bitcoin Core developers
+// Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -11,6 +11,10 @@
 #include "serialize.h"
 #include "uint256.h"
 
+static const int SERIALIZE_TRANSACTION_NO_WITNESS = 0x40000000;
+
+static const int WITNESS_SCALE_FACTOR = 4;
+
 /** An outpoint - a combination of a transaction hash and an index n into its vout */
 class COutPoint
 {
@@ -24,7 +28,7 @@ public:
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+    inline void SerializationOp(Stream& s, Operation ser_action) {
         READWRITE(hash);
         READWRITE(n);
     }
@@ -34,7 +38,8 @@ public:
 
     friend bool operator<(const COutPoint& a, const COutPoint& b)
     {
-        return (a.hash < b.hash || (a.hash == b.hash && a.n < b.n));
+        int cmp = a.hash.Compare(b.hash);
+        return cmp < 0 || (cmp == 0 && a.n < b.n);
     }
 
     friend bool operator==(const COutPoint& a, const COutPoint& b)
@@ -60,29 +65,52 @@ public:
     COutPoint prevout;
     CScript scriptSig;
     uint32_t nSequence;
+    CScriptWitness scriptWitness; //! Only serialized through CTransaction
+
+    /* Setting nSequence to this value for every input in a transaction
+     * disables nLockTime. */
+    static const uint32_t SEQUENCE_FINAL = 0xffffffff;
+
+    /* Below flags apply in the context of BIP 68*/
+    /* If this flag set, CTxIn::nSequence is NOT interpreted as a
+     * relative lock-time. */
+    static const uint32_t SEQUENCE_LOCKTIME_DISABLE_FLAG = (1 << 31);
+
+    /* If CTxIn::nSequence encodes a relative lock-time and this flag
+     * is set, the relative lock-time has units of 512 seconds,
+     * otherwise it specifies blocks with a granularity of 1. */
+    static const uint32_t SEQUENCE_LOCKTIME_TYPE_FLAG = (1 << 22);
+
+    /* If CTxIn::nSequence encodes a relative lock-time, this mask is
+     * applied to extract that lock-time from the sequence field. */
+    static const uint32_t SEQUENCE_LOCKTIME_MASK = 0x0000ffff;
+
+    /* In order to use the same number of bits to encode roughly the
+     * same wall-clock duration, and because blocks are naturally
+     * limited to occur every 600s on average, the minimum granularity
+     * for time-based relative lock-time is fixed at 512 seconds.
+     * Converting from CTxIn::nSequence to seconds is performed by
+     * multiplying by 512 = 2^9, or equivalently shifting up by
+     * 9 bits. */
+    static const int SEQUENCE_LOCKTIME_GRANULARITY = 9;
 
     CTxIn()
     {
-        nSequence = std::numeric_limits<unsigned int>::max();
+        nSequence = SEQUENCE_FINAL;
     }
 
-    explicit CTxIn(COutPoint prevoutIn, CScript scriptSigIn=CScript(), uint32_t nSequenceIn=std::numeric_limits<unsigned int>::max());
-    CTxIn(uint256 hashPrevTx, uint32_t nOut, CScript scriptSigIn=CScript(), uint32_t nSequenceIn=std::numeric_limits<uint32_t>::max());
+    explicit CTxIn(COutPoint prevoutIn, CScript scriptSigIn=CScript(), uint32_t nSequenceIn=SEQUENCE_FINAL);
+    CTxIn(uint256 hashPrevTx, uint32_t nOut, CScript scriptSigIn=CScript(), uint32_t nSequenceIn=SEQUENCE_FINAL);
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+    inline void SerializationOp(Stream& s, Operation ser_action) {
         READWRITE(prevout);
-        READWRITE(scriptSig);
+        READWRITE(*(CScriptBase*)(&scriptSig));
         READWRITE(nSequence);
     }
 
-    bool IsFinal() const
-    {
-        return (nSequence == std::numeric_limits<uint32_t>::max());
-    }
-
     friend bool operator==(const CTxIn& a, const CTxIn& b)
     {
         return (a.prevout   == b.prevout &&
@@ -117,9 +145,9 @@ public:
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
+    inline void SerializationOp(Stream& s, Operation ser_action) {
         READWRITE(nValue);
-        READWRITE(scriptPubKey);
+        READWRITE(*(CScriptBase*)(&scriptPubKey));
     }
 
     void SetNull()
@@ -133,30 +161,41 @@ public:
         return (nValue == -1);
     }
 
-    uint256 GetHash() const;
-
     CAmount GetDustThreshold(const CFeeRate &minRelayTxFee) const
     {
         // "Dust" is defined in terms of CTransaction::minRelayTxFee,
         // which has units satoshis-per-kilobyte.
         // If you'd pay more than 1/3 in fees
         // to spend something, then we consider it dust.
-        // A typical txout is 34 bytes big, and will
+        // A typical spendable non-segwit txout is 34 bytes big, and will
         // need a CTxIn of at least 148 bytes to spend:
-        // so dust is a txout less than 546 satoshis 
-        // with default minRelayTxFee.
-        // size_t nSize = GetSerializeSize(SER_DISK,0)+148u;
-        // return 3*minRelayTxFee.GetFee(nSize);
-        // Dogecoin: Dust is 1 COIN
-        return COIN;
+        // so dust is a spendable txout less than
+        // 546*minRelayTxFee/1000 (in satoshis).
+        // A typical spendable segwit txout is 31 bytes big, and will
+        // need a CTxIn of at least 67 bytes to spend:
+        // so dust is a spendable txout less than
+        // 294*minRelayTxFee/1000 (in satoshis).
+        if (scriptPubKey.IsUnspendable())
+            return 0;
+
+        size_t nSize = GetSerializeSize(*this, SER_DISK, 0);
+        int witnessversion = 0;
+        std::vector<unsigned char> witnessprogram;
+
+        if (scriptPubKey.IsWitnessProgram(witnessversion, witnessprogram)) {
+            // sum the sizes of the parts of a transaction input
+            // with 75% segwit discount applied to the script size.
+            nSize += (32 + 4 + 1 + (107 / WITNESS_SCALE_FACTOR) + 4);
+        } else {
+            nSize += (32 + 4 + 1 + 107 + 4); // the 148 mentioned above
+        }
+
+        return 3 * minRelayTxFee.GetFee(nSize);
     }
 
     bool IsDust(const CFeeRate &minRelayTxFee) const
     {
-        // Dogecoin: IsDust() detection disabled, allows any valid dust to be relayed.
-        // The fees imposed on each dust txo is considered sufficient spam deterrant.
-        // return (nValue < GetDustThreshold(minRelayTxFee));
-        return false;
+        return (nValue < GetDustThreshold(minRelayTxFee));
     }
 
     friend bool operator==(const CTxOut& a, const CTxOut& b)
@@ -175,19 +214,104 @@ public:
 
 struct CMutableTransaction;
 
+/**
+ * Basic transaction serialization format:
+ * - int32_t nVersion
+ * - std::vector<CTxIn> vin
+ * - std::vector<CTxOut> vout
+ * - uint32_t nLockTime
+ *
+ * Extended transaction serialization format:
+ * - int32_t nVersion
+ * - unsigned char dummy = 0x00
+ * - unsigned char flags (!= 0)
+ * - std::vector<CTxIn> vin
+ * - std::vector<CTxOut> vout
+ * - if (flags & 1):
+ *   - CTxWitness wit;
+ * - uint32_t nLockTime
+ */
+template<typename Stream, typename TxType>
+inline void UnserializeTransaction(TxType& tx, Stream& s) {
+    const bool fAllowWitness = !(s.GetVersion() & SERIALIZE_TRANSACTION_NO_WITNESS);
+
+    s >> tx.nVersion;
+    unsigned char flags = 0;
+    tx.vin.clear();
+    tx.vout.clear();
+    /* Try to read the vin. In case the dummy is there, this will be read as an empty vector. */
+    s >> tx.vin;
+    if (tx.vin.size() == 0 && fAllowWitness) {
+        /* We read a dummy or an empty vin. */
+        s >> flags;
+        if (flags != 0) {
+            s >> tx.vin;
+            s >> tx.vout;
+        }
+    } else {
+        /* We read a non-empty vin. Assume a normal vout follows. */
+        s >> tx.vout;
+    }
+    if ((flags & 1) && fAllowWitness) {
+        /* The witness flag is present, and we support witnesses. */
+        flags ^= 1;
+        for (size_t i = 0; i < tx.vin.size(); i++) {
+            s >> tx.vin[i].scriptWitness.stack;
+        }
+    }
+    if (flags) {
+        /* Unknown flag in the serialization */
+        throw std::ios_base::failure("Unknown transaction optional data");
+    }
+    s >> tx.nLockTime;
+}
+
+template<typename Stream, typename TxType>
+inline void SerializeTransaction(const TxType& tx, Stream& s) {
+    const bool fAllowWitness = !(s.GetVersion() & SERIALIZE_TRANSACTION_NO_WITNESS);
+
+    s << tx.nVersion;
+    unsigned char flags = 0;
+    // Consistency check
+    if (fAllowWitness) {
+        /* Check whether witnesses need to be serialized. */
+        if (tx.HasWitness()) {
+            flags |= 1;
+        }
+    }
+    if (flags) {
+        /* Use extended format in case witnesses are to be serialized. */
+        std::vector<CTxIn> vinDummy;
+        s << vinDummy;
+        s << flags;
+    }
+    s << tx.vin;
+    s << tx.vout;
+    if (flags & 1) {
+        for (size_t i = 0; i < tx.vin.size(); i++) {
+            s << tx.vin[i].scriptWitness.stack;
+        }
+    }
+    s << tx.nLockTime;
+}
+
+
 /** The basic transaction that is broadcasted on the network and contained in
  * blocks.  A transaction can contain multiple inputs and outputs.
  */
 class CTransaction
 {
-private:
-    /** Memory only. */
-    const uint256 hash;
-    void UpdateHash() const;
-
 public:
+    // Default transaction version.
+    // Dogecoin: Temporarily restricted to v1 for compatibility with 1.10
     static const int32_t CURRENT_VERSION=1;
 
+    // Changing the default transaction version requires a two step process: first
+    // adapting relay policy by bumping MAX_STANDARD_VERSION, and then later date
+    // bumping the default CURRENT_VERSION at which point both CURRENT_VERSION and
+    // MAX_STANDARD_VERSION will be equal.
+    static const int32_t MAX_STANDARD_VERSION=2;
+
     // The local variables are made const to prevent unintended modification
     // without updating the cached hash value. However, CTransaction is not
     // actually immutable; deserialization and assignment are implemented,
@@ -198,27 +322,30 @@ public:
     const std::vector<CTxOut> vout;
     const uint32_t nLockTime;
 
+private:
+    /** Memory only. */
+    const uint256 hash;
+
+    uint256 ComputeHash() const;
+
+public:
     /** Construct a CTransaction that qualifies as IsNull() */
     CTransaction();
 
     /** Convert a CMutableTransaction into a CTransaction. */
     CTransaction(const CMutableTransaction &tx);
+    CTransaction(CMutableTransaction &&tx);
 
-    CTransaction& operator=(const CTransaction& tx);
-
-    ADD_SERIALIZE_METHODS;
-
-    template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
-        READWRITE(*const_cast<int32_t*>(&this->nVersion));
-        nVersion = this->nVersion;
-        READWRITE(*const_cast<std::vector<CTxIn>*>(&vin));
-        READWRITE(*const_cast<std::vector<CTxOut>*>(&vout));
-        READWRITE(*const_cast<uint32_t*>(&nLockTime));
-        if (ser_action.ForRead())
-            UpdateHash();
+    template <typename Stream>
+    inline void Serialize(Stream& s) const {
+        SerializeTransaction(*this, s);
     }
 
+    /** This deserializing constructor is provided instead of an Unserialize method.
+     *  Unserialize is not possible, since it would require overwriting const fields. */
+    template <typename Stream>
+    CTransaction(deserialize_type, Stream& s) : CTransaction(CMutableTransaction(deserialize, s)) {}
+
     bool IsNull() const {
         return vin.empty() && vout.empty();
     }
@@ -227,6 +354,9 @@ public:
         return hash;
     }
 
+    // Compute a hash that includes both transaction and witness data
+    uint256 GetWitnessHash() const;
+
     // Return sum of txouts.
     CAmount GetValueOut() const;
     // GetValueIn() is a method on CCoinsViewCache, because
@@ -238,6 +368,13 @@ public:
     // Compute modified tx size for priority calculation (optionally given tx size)
     unsigned int CalculateModifiedSize(unsigned int nTxSize=0) const;
 
+    /**
+     * Get the total transaction size in bytes, including witness data.
+     * "Total Size" defined in BIP141 and BIP144.
+     * @return Total transaction size in bytes
+     */
+    unsigned int GetTotalSize() const;
+
     bool IsCoinBase() const
     {
         return (vin.size() == 1 && vin[0].prevout.IsNull());
@@ -254,6 +391,16 @@ public:
     }
 
     std::string ToString() const;
+
+    bool HasWitness() const
+    {
+        for (size_t i = 0; i < vin.size(); i++) {
+            if (!vin[i].scriptWitness.IsNull()) {
+                return true;
+            }
+        }
+        return false;
+    }
 };
 
 /** A mutable version of CTransaction. */
@@ -267,21 +414,48 @@ struct CMutableTransaction
     CMutableTransaction();
     CMutableTransaction(const CTransaction& tx);
 
-    ADD_SERIALIZE_METHODS;
+    template <typename Stream>
+    inline void Serialize(Stream& s) const {
+        SerializeTransaction(*this, s);
+    }
 
-    template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion) {
-        READWRITE(this->nVersion);
-        nVersion = this->nVersion;
-        READWRITE(vin);
-        READWRITE(vout);
-        READWRITE(nLockTime);
+
+    template <typename Stream>
+    inline void Unserialize(Stream& s) {
+        UnserializeTransaction(*this, s);
+    }
+
+    template <typename Stream>
+    CMutableTransaction(deserialize_type, Stream& s) {
+        Unserialize(s);
     }
 
     /** Compute the hash of this CMutableTransaction. This is computed on the
      * fly, as opposed to GetHash() in CTransaction, which uses a cached result.
      */
     uint256 GetHash() const;
+
+    friend bool operator==(const CMutableTransaction& a, const CMutableTransaction& b)
+    {
+        return a.GetHash() == b.GetHash();
+    }
+
+    bool HasWitness() const
+    {
+        for (size_t i = 0; i < vin.size(); i++) {
+            if (!vin[i].scriptWitness.IsNull()) {
+                return true;
+            }
+        }
+        return false;
+    }
 };
 
+typedef std::shared_ptr<const CTransaction> CTransactionRef;
+static inline CTransactionRef MakeTransactionRef() { return std::make_shared<const CTransaction>(); }
+template <typename Tx> static inline CTransactionRef MakeTransactionRef(Tx&& txIn) { return std::make_shared<const CTransaction>(std::forward<Tx>(txIn)); }
+
+/** Compute the weight of a transaction, as defined by BIP 141 */
+int64_t GetTransactionWeight(const CTransaction &tx);
+
 #endif // BITCOIN_PRIMITIVES_TRANSACTION_H