From c71c3511769b7726498dd79213aa5ef970c5e3a2 Mon Sep 17 00:00:00 2001
From: Ross Nicoll <jrn@jrn.me.uk>
Date: Tue, 28 Jul 2015 19:02:55 +0100
Subject: [PATCH] Correct BIP 66 patches

---
 src/main.cpp | 41 +++++++++++++++++++++--------------------
 src/script.h |  1 +
 2 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index ba397a59e..b85236f8c 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -2761,29 +2761,30 @@ bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex** ppindex,
                              REJECT_INVALID, "bad-txns-nonfinal");
         }
 
-        // Reject block.nVersion=2 blocks when 95% (75% on testnet) of the network has upgraded:
-        if (block.nVersion < 3)
+    // Reject block.nVersion=2 blocks when 95% (75% on testnet) of the network has upgraded:
+    if (block.nVersion < 3)
+    {
+        if ((!TestNet() && CBlockIndex::IsSuperMajority(3, pindex->pprev, 950, 1000)) ||
+            (TestNet() && CBlockIndex::IsSuperMajority(3, pindex->pprev, 75, 100)))
         {
-            if ((!TestNet() && CBlockIndex::IsSuperMajority(3, pindexPrev, 950, 1000)) ||
-                (TestNet() && CBlockIndex::IsSuperMajority(3, pindexPrev, 75, 100)))
-            {
-                return state.Invalid(error("AcceptBlock() : rejected nVersion=2 block"),
-                                     REJECT_OBSOLETE, "bad-version");
-            }
+            return state.Invalid(error("AcceptBlock() : rejected nVersion=2 block"),
+                             REJECT_OBSOLETE, "bad-version");
         }
-        // Enforce block.nVersion=2 rule that the coinbase starts with serialized block height
-        if (block.nVersion >= 2)
+    }
+    // Enforce block.nVersion=2 rule that the coinbase starts with serialized block height
+    if (block.nVersion >= 2)
+    {
+        // if 750 of the last 1,000 blocks are version 2 or greater (51/100 if testnet):
+        if ((!TestNet() && CBlockIndex::IsSuperMajority(2, pindex->pprev, 750, 1000)) ||
+            (TestNet() && CBlockIndex::IsSuperMajority(2, pindex->pprev, 51, 100)))
         {
-            // if 750 of the last 1,000 blocks are version 2 or greater (51/100 if testnet):
-            if ((!TestNet() && CBlockIndex::IsSuperMajority(2, pindex->pprev, 750, 1000)) ||
-                (TestNet() && CBlockIndex::IsSuperMajority(2, pindex->pprev, 51, 100)))
-                CScript expect = CScript() << nHeight;
-                if (block.vtx[0].vin[0].scriptSig.size() < expect.size() ||
-                    !std::equal(expect.begin(), expect.end(), block.vtx[0].vin[0].scriptSig.begin())) {
-                    pindex->nStatus |= BLOCK_FAILED_VALID;
-                    return state.DoS(100, error("AcceptBlock() : block height mismatch in coinbase"),
-                                    REJECT_INVALID, "bad-cb-height");
-                }
+            CScript expect = CScript() << nHeight;
+            if (block.vtx[0].vin[0].scriptSig.size() < expect.size() ||
+                !std::equal(expect.begin(), expect.end(), block.vtx[0].vin[0].scriptSig.begin())) {
+                pindex->nStatus |= BLOCK_FAILED_VALID;
+                return state.DoS(100, error("AcceptBlock() : block height mismatch in coinbase"),
+                                 REJECT_INVALID, "bad-cb-height");
+            }
         }
     }
 
diff --git a/src/script.h b/src/script.h
index 737755d8a..0fd6634f4 100644
--- a/src/script.h
+++ b/src/script.h
@@ -191,6 +191,7 @@ enum
     SCRIPT_VERIFY_LOW_S     = (1U << 2), // enforce low S values (<n/2) in signatures (depends on STRICTENC)
     SCRIPT_VERIFY_NOCACHE   = (1U << 3), // do not store results in signature cache (but do query it)
     SCRIPT_VERIFY_DERSIG    = (1U << 4), // enforce signature encodings as defined by BIP 66 (which is a softfork, while STRICTENC is not)
+    SCRIPT_VERIFY_NULLDUMMY = (1U << 5), // verify dummy stack item consumed by CHECKMULTISIG is of zero-length
 };
 
 // Mandatory script verification flags that all new blocks must comply with for