From f6cc96084f4ab6461a99f9efece16cfdf9d8f738 Mon Sep 17 00:00:00 2001
From: Xinxi Wang <xinxi.wang@ieee.org>
Date: Mon, 14 Nov 2016 01:49:47 -0800
Subject: [PATCH] Litecoin: Reject v1 blocks at specific block height

---
 src/main.cpp | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/main.cpp b/src/main.cpp
index 2d909aef9..fd2033685 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3543,8 +3543,29 @@ bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationState& sta
     if (block.GetBlockTime() > nAdjustedTime + 2 * 60 * 60)
         return state.Invalid(false, REJECT_INVALID, "time-too-new", "block timestamp too far in the future");
 
+    // Litecoin: Reject block.nVersion=1 blocks (mainnet >= 710000, testnet >= 400000, regtest uses supermajority)
+    const int nHeight = pindexPrev->nHeight+1;    
+    bool enforceV2 = false;
+    if (block.nVersion < 2) {
+        if (consensusParams.BIP34Height != -1) {
+            // Mainnet 710k, Testnet 400k
+            if (nHeight >= consensusParams.BIP34Height)
+                enforceV2 = true;
+        }
+        else {
+            // Regtest and Unittest: use Bitcoin's supermajority rule
+            if (IsSuperMajority(2, pindexPrev, consensusParams.nMajorityRejectBlockOutdated, consensusParams))
+                enforceV2 = true;
+        }
+    }
+
+    if (enforceV2) {
+        return state.Invalid(false, REJECT_OBSOLETE, strprintf("bad-version(0x%08x)", block.nVersion),
+                             strprintf("rejected nVersion=0x%08x block", block.nVersion));
+    }
+
     // Reject outdated version blocks when 95% (75% on testnet) of the network has upgraded:
-    for (int32_t version = 2; version < 5; ++version) // check for version 2, 3 and 4 upgrades
+    for (int32_t version = 3; version < 5; ++version) // check for version 2, 3 and 4 upgrades
         if (block.nVersion < version && IsSuperMajority(version, pindexPrev, consensusParams.nMajorityRejectBlockOutdated, consensusParams))
             return state.Invalid(false, REJECT_OBSOLETE, strprintf("bad-version(0x%08x)", version - 1),
                                  strprintf("rejected nVersion=0x%08x block", version - 1));