From b7b4318f3a65d6e55d44bff5da1091ec0b3a26d2 Mon Sep 17 00:00:00 2001
From: Matt Corallo <git@bluematt.me>
Date: Tue, 11 Nov 2014 21:06:15 -0800
Subject: [PATCH] Make CTxMemPool::check more thourough by using CheckInputs

---
 src/txmempool.cpp | 30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index ff04a8ad9a..6ecd64636b 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -6,7 +6,7 @@
 #include "txmempool.h"
 
 #include "clientversion.h"
-#include "main.h" // for COINBASE_MATURITY
+#include "main.h"
 #include "streams.h"
 #include "util.h"
 #include "utilmoneystr.h"
@@ -539,17 +539,22 @@ void CTxMemPool::check(const CCoinsViewCache *pcoins) const
 
     uint64_t checkTotal = 0;
 
+    CCoinsViewCache mempoolDuplicate(const_cast<CCoinsViewCache*>(pcoins));
+
     LOCK(cs);
+    list<const CTxMemPoolEntry*> waitingOnDependants;
     for (std::map<uint256, CTxMemPoolEntry>::const_iterator it = mapTx.begin(); it != mapTx.end(); it++) {
         unsigned int i = 0;
         checkTotal += it->second.GetTxSize();
         const CTransaction& tx = it->second.GetTx();
+        bool fDependsWait = false;
         BOOST_FOREACH(const CTxIn &txin, tx.vin) {
             // Check that every mempool transaction's inputs refer to available coins, or other mempool tx's.
             std::map<uint256, CTxMemPoolEntry>::const_iterator it2 = mapTx.find(txin.prevout.hash);
             if (it2 != mapTx.end()) {
                 const CTransaction& tx2 = it2->second.GetTx();
                 assert(tx2.vout.size() > txin.prevout.n && !tx2.vout[txin.prevout.n].IsNull());
+                fDependsWait = true;
             } else {
                 const CCoins* coins = pcoins->AccessCoins(txin.prevout.hash);
                 assert(coins && coins->IsAvailable(txin.prevout.n));
@@ -561,6 +566,29 @@ void CTxMemPool::check(const CCoinsViewCache *pcoins) const
             assert(it3->second.n == i);
             i++;
         }
+        if (fDependsWait)
+            waitingOnDependants.push_back(&it->second);
+        else {
+            CValidationState state; CTxUndo undo;
+            assert(CheckInputs(tx, state, mempoolDuplicate, false, 0, false, NULL));
+            UpdateCoins(tx, state, mempoolDuplicate, undo, 1000000);
+        }
+    }
+    unsigned int stepsSinceLastRemove = 0;
+    while (!waitingOnDependants.empty()) {
+        const CTxMemPoolEntry* entry = waitingOnDependants.front();
+        waitingOnDependants.pop_front();
+        CValidationState state;
+        if (!mempoolDuplicate.HaveInputs(entry->GetTx())) {
+            waitingOnDependants.push_back(entry);
+            stepsSinceLastRemove++;
+            assert(stepsSinceLastRemove < waitingOnDependants.size());
+        } else {
+            assert(CheckInputs(entry->GetTx(), state, mempoolDuplicate, false, 0, false, NULL));
+            CTxUndo undo;
+            UpdateCoins(entry->GetTx(), state, mempoolDuplicate, undo, 1000000);
+            stepsSinceLastRemove = 0;
+        }
     }
     for (std::map<COutPoint, CInPoint>::const_iterator it = mapNextTx.begin(); it != mapNextTx.end(); it++) {
         uint256 hash = it->second.ptx->GetHash();