From 2c901fd87d62d1d393af65dd1a461d30554e2955 Mon Sep 17 00:00:00 2001
From: Sean Bowe <ewillbefull@gmail.com>
Date: Mon, 13 Jun 2016 11:52:46 -0600
Subject: [PATCH] Refactor contextual and noncontextual input checks.

---
 src/main.cpp | 41 +++++++++++++++++++++++++++++++----------
 src/main.h   |  3 +++
 2 files changed, 34 insertions(+), 10 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index a16d59f8f..09c357b01 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1604,7 +1604,7 @@ bool CScriptCheck::operator()() {
     return true;
 }
 
-bool ContextualCheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &inputs, bool fScriptChecks, unsigned int flags, bool cacheStore, std::vector<CScriptCheck> *pvChecks)
+bool NonContextualCheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &inputs, bool fScriptChecks, unsigned int flags, bool cacheStore, std::vector<CScriptCheck> *pvChecks)
 {
     if (!tx.IsCoinBase())
     {
@@ -1620,10 +1620,6 @@ bool ContextualCheckInputs(const CTransaction& tx, CValidationState &state, cons
         if (!inputs.HavePourRequirements(tx))
             return state.Invalid(error("CheckInputs(): %s pour requirements not met", tx.GetHash().ToString()));
 
-        // While checking, GetBestBlock() refers to the parent block.
-        // This is also true for mempool checks.
-        CBlockIndex *pindexPrev = mapBlockIndex.find(inputs.GetBestBlock())->second;
-        int nSpendHeight = pindexPrev->nHeight + 1;
         CAmount nValueIn = 0;
         CAmount nFees = 0;
         for (unsigned int i = 0; i < tx.vin.size(); i++)
@@ -1632,12 +1628,8 @@ bool ContextualCheckInputs(const CTransaction& tx, CValidationState &state, cons
             const CCoins *coins = inputs.AccessCoins(prevout.hash);
             assert(coins);
 
-            // If prev is coinbase, check that it's matured
             if (coins->IsCoinBase()) {
-                if (nSpendHeight - coins->nHeight < COINBASE_MATURITY)
-                    return state.Invalid(
-                        error("CheckInputs(): tried to spend coinbase at depth %d", nSpendHeight - coins->nHeight),
-                        REJECT_INVALID, "bad-txns-premature-spend-of-coinbase");
+                
             }
 
             // Check for negative or overflow input values
@@ -1715,6 +1707,35 @@ bool ContextualCheckInputs(const CTransaction& tx, CValidationState &state, cons
     return true;
 }
 
+bool ContextualCheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &inputs, bool fScriptChecks, unsigned int flags, bool cacheStore, std::vector<CScriptCheck> *pvChecks)
+{
+    if (!tx.IsCoinBase())
+    {
+        // While checking, GetBestBlock() refers to the parent block.
+        // This is also true for mempool checks.
+        CBlockIndex *pindexPrev = mapBlockIndex.find(inputs.GetBestBlock())->second;
+        int nSpendHeight = pindexPrev->nHeight + 1;
+        for (unsigned int i = 0; i < tx.vin.size(); i++)
+        {
+            const COutPoint &prevout = tx.vin[i].prevout;
+            const CCoins *coins = inputs.AccessCoins(prevout.hash);
+            assert(coins);
+
+            // If prev is coinbase, check that it's matured
+            if (coins->IsCoinBase()) {
+                if (nSpendHeight - coins->nHeight < COINBASE_MATURITY)
+                    return state.Invalid(
+                        error("CheckInputs(): tried to spend coinbase at depth %d", nSpendHeight - coins->nHeight),
+                        REJECT_INVALID, "bad-txns-premature-spend-of-coinbase");
+            }
+        }
+    }
+
+    return NonContextualCheckInputs(
+        tx, state, inputs, fScriptChecks, flags, cacheStore, pvChecks
+    );
+}
+
 namespace {
 
 bool UndoWriteToDisk(const CBlockUndo& blockundo, CDiskBlockPos& pos, const uint256& hashBlock, const CMessageHeader::MessageStartChars& messageStart)
diff --git a/src/main.h b/src/main.h
index 9357ce9f5..f1627e621 100644
--- a/src/main.h
+++ b/src/main.h
@@ -320,6 +320,9 @@ unsigned int GetP2SHSigOpCount(const CTransaction& tx, const CCoinsViewCache& ma
 bool ContextualCheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &view, bool fScriptChecks,
                            unsigned int flags, bool cacheStore, std::vector<CScriptCheck> *pvChecks = NULL);
 
+bool NonContextualCheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &view, bool fScriptChecks,
+                              unsigned int flags, bool cacheStore, std::vector<CScriptCheck> *pvChecks = NULL);
+
 /** Apply the effects of this transaction on the UTXO set represented by view */
 void UpdateCoins(const CTransaction& tx, CValidationState &state, CCoinsViewCache &inputs, int nHeight);