From 722d811f892f32fdf973ea3f5c53b16e1ec43c7d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jorge=20Tim=C3=B3n?= <jtimon@jtimon.cc>
Date: Sat, 16 Jul 2016 20:57:42 +0200
Subject: [PATCH] Mempool: Use Consensus::CheckTxInputs direclty over
 main::CheckInputs

---
 src/main.h        | 17 +++++++++++++----
 src/txmempool.cpp |  9 +++++++--
 2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/src/main.h b/src/main.h
index 39bffd286..df11c39e3 100644
--- a/src/main.h
+++ b/src/main.h
@@ -339,6 +339,8 @@ bool ContextualCheckTransaction(const CTransaction& tx, CValidationState &state,
 /** Apply the effects of this transaction on the UTXO set represented by view */
 void UpdateCoins(const CTransaction& tx, CCoinsViewCache& inputs, int nHeight);
 
+/** Transaction validation functions */
+
 /** Context-independent validity checks */
 bool CheckTransaction(const CTransaction& tx, CValidationState& state, libzcash::ProofVerifier& verifier);
 bool CheckTransactionWithoutProofVerification(const CTransaction& tx, CValidationState &state);
@@ -348,6 +350,17 @@ bool CheckTransactionWithoutProofVerification(const CTransaction& tx, CValidatio
  */
 bool IsStandardTx(const CTransaction& tx, std::string& reason, int nHeight = 0);
 
+namespace Consensus {
+
+/**
+ * Check whether all inputs of this transaction are valid (no double spends and amounts)
+ * This does not modify the UTXO set. This does not check scripts and sigs.
+ * Preconditions: tx.IsCoinBase() is false.
+ */
+bool CheckTxInputs(const CTransaction& tx, CValidationState& state, const CCoinsViewCache& inputs, int nSpendHeight, const Consensus::Params& consensusParams);
+
+} // namespace Consensus
+
 /**
  * Check if transaction is final and can be included in a block with the
  * specified height and time. Consensus critical.
@@ -536,10 +549,6 @@ extern CBlockTreeDB *pblocktree;
  */
 int GetSpendHeight(const CCoinsViewCache& inputs);
 
-namespace Consensus {
-bool CheckTxInputs(const CTransaction& tx, CValidationState& state, const CCoinsViewCache& inputs, int nSpendHeight, const Consensus::Params& consensusParams);
-}
-
 /** Return a CMutableTransaction with contextual default values based on set of consensus rules at height */
 CMutableTransaction CreateNewContextualCMutableTransaction(const Consensus::Params& consensusParams, int nHeight);
 
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index 5492bc4e5..6b3c16f2a 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -329,6 +329,7 @@ void CTxMemPool::check(const CCoinsViewCache *pcoins) const
     uint64_t innerUsage = 0;
 
     CCoinsViewCache mempoolDuplicate(const_cast<CCoinsViewCache*>(pcoins));
+    const int64_t nSpendHeight = GetSpendHeight(mempoolDuplicate);
 
     LOCK(cs);
     list<const CTxMemPoolEntry*> waitingOnDependants;
@@ -383,7 +384,9 @@ void CTxMemPool::check(const CCoinsViewCache *pcoins) const
             waitingOnDependants.push_back(&(*it));
         else {
             CValidationState state;
-            assert(ContextualCheckInputs(tx, state, mempoolDuplicate, false, 0, false, Params().GetConsensus(), NULL));
+            bool fCheckResult = tx.IsCoinBase() ||
+                Consensus::CheckTxInputs(tx, state, mempoolDuplicate, nSpendHeight, Params().GetConsensus());
+            assert(fCheckResult);
             UpdateCoins(tx, mempoolDuplicate, 1000000);
         }
     }
@@ -397,7 +400,9 @@ void CTxMemPool::check(const CCoinsViewCache *pcoins) const
             stepsSinceLastRemove++;
             assert(stepsSinceLastRemove < waitingOnDependants.size());
         } else {
-            assert(ContextualCheckInputs(entry->GetTx(), state, mempoolDuplicate, false, 0, false, Params().GetConsensus(), NULL));
+            bool fCheckResult = entry->GetTx().IsCoinBase() ||
+                Consensus::CheckTxInputs(entry->GetTx(), state, mempoolDuplicate, nSpendHeight, Params().GetConsensus());
+            assert(fCheckResult);
             UpdateCoins(entry->GetTx(), mempoolDuplicate, 1000000);
             stepsSinceLastRemove = 0;
         }