From c293a2efd280fd52873403af0ea6305aa4ca6948 Mon Sep 17 00:00:00 2001
From: Warren Togami <wtogami@gmail.com>
Date: Mon, 19 Jan 2015 01:51:55 -1000
Subject: [PATCH] Litecoin: Enforce v2 blocks, mainnet >= 710k, testnet >= 400k

regtest/unittest uses supermajority rule
---
 src/chainparams.cpp | 12 ++++++++++++
 src/chainparams.h   |  6 ++++++
 src/main.cpp        | 43 ++++++++++++++++++++++++++++++++++++++-----
 3 files changed, 56 insertions(+), 5 deletions(-)

diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 9c62594d1..e8b06c738 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -176,6 +176,9 @@ public:
         fMineBlocksOnDemand = false;
         fSkipProofOfWorkCheck = false;
         fTestnetToBeDeprecatedFieldRPC = false;
+
+        // Litecoin: Mainnet v2 enforced as of block 710k
+        nEnforceV2AfterHeight = 710000;
     }
 
     const Checkpoints::CCheckpointData& Checkpoints() const 
@@ -233,6 +236,9 @@ public:
         fRequireStandard = false;
         fMineBlocksOnDemand = false;
         fTestnetToBeDeprecatedFieldRPC = true;
+
+        // Litecoin: Testnet v2 enforced as of block 400k
+        nEnforceV2AfterHeight = 400000;
     }
     const Checkpoints::CCheckpointData& Checkpoints() const 
     {
@@ -278,6 +284,9 @@ public:
         fRequireStandard = false;
         fMineBlocksOnDemand = true;
         fTestnetToBeDeprecatedFieldRPC = false;
+
+        // Litecoin: v2 enforced using Bitcoin's supermajority rule
+        nEnforceV2AfterHeight = -1;
     }
     const Checkpoints::CCheckpointData& Checkpoints() const 
     {
@@ -303,6 +312,9 @@ public:
         fDefaultCheckMemPool = true;
         fAllowMinDifficultyBlocks = false;
         fMineBlocksOnDemand = true;
+
+        // Litecoin: v2 enforced using Bitcoin's supermajority rule
+        nEnforceV2AfterHeight = -1;
     }
 
     const Checkpoints::CCheckpointData& Checkpoints() const 
diff --git a/src/chainparams.h b/src/chainparams.h
index 5d1ee1d3c..488c8e55c 100644
--- a/src/chainparams.h
+++ b/src/chainparams.h
@@ -79,6 +79,9 @@ public:
     const std::vector<unsigned char>& Base58Prefix(Base58Type type) const { return base58Prefixes[type]; }
     const std::vector<CAddress>& FixedSeeds() const { return vFixedSeeds; }
     virtual const Checkpoints::CCheckpointData& Checkpoints() const = 0;
+
+    // Litecoin: Height to enforce v2 block
+    int EnforceV2AfterHeight() const { return nEnforceV2AfterHeight; }
 protected:
     CChainParams() {}
 
@@ -109,6 +112,9 @@ protected:
     bool fMineBlocksOnDemand;
     bool fSkipProofOfWorkCheck;
     bool fTestnetToBeDeprecatedFieldRPC;
+
+    // Litecoin: Height to enforce v2 blocks
+    int nEnforceV2AfterHeight;
 };
 
 /** 
diff --git a/src/main.cpp b/src/main.cpp
index c8a0d10e4..b35bf0dbf 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -2518,9 +2518,25 @@ bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationState& sta
     if (pcheckpoint && nHeight < pcheckpoint->nHeight)
         return state.DoS(100, error("%s : forked chain older than last checkpoint (height %d)", __func__, nHeight));
 
-    // Reject block.nVersion=1 blocks when 95% (75% on testnet) of the network has upgraded:
-    if (block.nVersion < 2 && 
-        CBlockIndex::IsSuperMajority(2, pindexPrev, Params().RejectBlockOutdatedMajority()))
+    // Litecoin: Reject block.nVersion=1 blocks (mainnet >= 710000, testnet >= 400000, regtest uses supermajority)
+    bool enforceV2 = false;
+    if (block.nVersion < 2)
+    {
+        if (Params().EnforceV2AfterHeight() != -1)
+        {
+            // Mainnet 710k, Testnet 400k
+            if (nHeight >= Params().EnforceV2AfterHeight())
+                enforceV2 = true;
+        }
+        else
+        {
+            // Regtest and Unittest: use Bitcoin's supermajority rule
+            if (CBlockIndex::IsSuperMajority(2, pindexPrev, Params().RejectBlockOutdatedMajority()))
+                enforceV2 = true;
+        }
+    }
+
+    if (enforceV2)
     {
         return state.Invalid(error("%s : rejected nVersion=1 block", __func__),
                              REJECT_OBSOLETE, "bad-version");
@@ -2546,10 +2562,27 @@ bool ContextualCheckBlock(const CBlock& block, CValidationState& state, CBlockIn
             return state.DoS(10, error("%s : contains a non-final transaction", __func__), REJECT_INVALID, "bad-txns-nonfinal");
         }
 
+    // Litecoin: (mainnet >= 710000, testnet >= 400000, regtest uses supermajority)
     // Enforce block.nVersion=2 rule that the coinbase starts with serialized block height
     // if 750 of the last 1,000 blocks are version 2 or greater (51/100 if testnet):
-    if (block.nVersion >= 2 && 
-        CBlockIndex::IsSuperMajority(2, pindexPrev, Params().EnforceBlockUpgradeMajority()))
+    bool checkHeightMismatch = false;
+    if (block.nVersion >= 2)
+    {
+        if (Params().EnforceV2AfterHeight() != -1)
+        {
+            // Mainnet 710k, Testnet 400k
+            if (nHeight >= Params().EnforceV2AfterHeight())
+                checkHeightMismatch = true;
+        }
+        else
+        {
+            // Regtest and Unittest: use Bitcoin's supermajority rule
+            if (CBlockIndex::IsSuperMajority(2, pindexPrev, Params().EnforceBlockUpgradeMajority()))
+                checkHeightMismatch = true;
+        }
+    }
+
+    if (checkHeightMismatch)
     {
         CScript expect = CScript() << nHeight;
         if (block.vtx[0].vin[0].scriptSig.size() < expect.size() ||