From 6d22b2b17b7852bb3dc32dbbbf2f5dff4fb98648 Mon Sep 17 00:00:00 2001
From: Matt Corallo <git@bluematt.me>
Date: Tue, 11 Apr 2017 16:04:37 -0400
Subject: [PATCH] Pull script verify flags calculation out of ConnectBlock

---
 src/validation.cpp | 62 ++++++++++++++++++++++++++++++----------------
 1 file changed, 40 insertions(+), 22 deletions(-)

diff --git a/src/validation.cpp b/src/validation.cpp
index eaefa9541..5b746229c 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -312,6 +312,9 @@ bool CheckSequenceLocks(const CTransaction &tx, int flags, LockPoints* lp, bool
     return EvaluateSequenceLocks(index, lockPair);
 }
 
+// Returns the script flags which should be checked for a given block
+static unsigned int GetBlockScriptFlags(const CBlockIndex* pindex, const Consensus::Params& chainparams);
+
 static void LimitMempoolSize(CTxMemPool& pool, size_t limit, unsigned long age) {
     int expired = pool.Expire(GetTime() - age);
     if (expired != 0) {
@@ -1475,6 +1478,41 @@ public:
 // Protected by cs_main
 static ThresholdConditionCache warningcache[VERSIONBITS_NUM_BITS];
 
+static unsigned int GetBlockScriptFlags(const CBlockIndex* pindex, const Consensus::Params& consensusparams) {
+    AssertLockHeld(cs_main);
+
+    // BIP16 didn't become active until Apr 1 2012
+    int64_t nBIP16SwitchTime = 1333238400;
+    bool fStrictPayToScriptHash = (pindex->GetBlockTime() >= nBIP16SwitchTime);
+
+    unsigned int flags = fStrictPayToScriptHash ? SCRIPT_VERIFY_P2SH : SCRIPT_VERIFY_NONE;
+
+    // Start enforcing the DERSIG (BIP66) rule
+    if (pindex->nHeight >= consensusparams.BIP66Height) {
+        flags |= SCRIPT_VERIFY_DERSIG;
+    }
+
+    // Start enforcing CHECKLOCKTIMEVERIFY (BIP65) rule
+    if (pindex->nHeight >= consensusparams.BIP65Height) {
+        flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY;
+    }
+
+    // Start enforcing BIP68 (sequence locks) and BIP112 (CHECKSEQUENCEVERIFY) using versionbits logic.
+    if (VersionBitsState(pindex->pprev, consensusparams, Consensus::DEPLOYMENT_CSV, versionbitscache) == THRESHOLD_ACTIVE) {
+        flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY;
+    }
+
+    // Start enforcing WITNESS rules using versionbits logic.
+    if (IsWitnessEnabled(pindex->pprev, consensusparams)) {
+        flags |= SCRIPT_VERIFY_WITNESS;
+        flags |= SCRIPT_VERIFY_NULLDUMMY;
+    }
+
+    return flags;
+}
+
+
+
 static int64_t nTimeCheck = 0;
 static int64_t nTimeForks = 0;
 static int64_t nTimeVerify = 0;
@@ -1578,34 +1616,14 @@ static bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockInd
         }
     }
 
-    // BIP16 didn't become active until Apr 1 2012
-    int64_t nBIP16SwitchTime = 1333238400;
-    bool fStrictPayToScriptHash = (pindex->GetBlockTime() >= nBIP16SwitchTime);
-
-    unsigned int flags = fStrictPayToScriptHash ? SCRIPT_VERIFY_P2SH : SCRIPT_VERIFY_NONE;
-
-    // Start enforcing the DERSIG (BIP66) rule
-    if (pindex->nHeight >= chainparams.GetConsensus().BIP66Height) {
-        flags |= SCRIPT_VERIFY_DERSIG;
-    }
-
-    // Start enforcing CHECKLOCKTIMEVERIFY (BIP65) rule
-    if (pindex->nHeight >= chainparams.GetConsensus().BIP65Height) {
-        flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY;
-    }
-
     // Start enforcing BIP68 (sequence locks) and BIP112 (CHECKSEQUENCEVERIFY) using versionbits logic.
     int nLockTimeFlags = 0;
     if (VersionBitsState(pindex->pprev, chainparams.GetConsensus(), Consensus::DEPLOYMENT_CSV, versionbitscache) == THRESHOLD_ACTIVE) {
-        flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY;
         nLockTimeFlags |= LOCKTIME_VERIFY_SEQUENCE;
     }
 
-    // Start enforcing WITNESS rules using versionbits logic.
-    if (IsWitnessEnabled(pindex->pprev, chainparams.GetConsensus())) {
-        flags |= SCRIPT_VERIFY_WITNESS;
-        flags |= SCRIPT_VERIFY_NULLDUMMY;
-    }
+    // Get the script flags for this block
+    unsigned int flags = GetBlockScriptFlags(pindex, chainparams.GetConsensus());
 
     int64_t nTime2 = GetTimeMicros(); nTimeForks += nTime2 - nTime1;
     LogPrint(BCLog::BENCH, "    - Fork checks: %.2fms [%.2fs]\n", 0.001 * (nTime2 - nTime1), nTimeForks * 0.000001);