From 13870b56fcd0bfacedce3ae42a3de3d5e9dc7bc1 Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter.wuille@gmail.com>
Date: Tue, 25 Apr 2017 11:29:37 -0700
Subject: [PATCH] Replace CCoins-based CTxMemPool::pruneSpent with isSpent

---
 src/rest.cpp           |  3 +--
 src/rpc/blockchain.cpp |  3 +--
 src/txmempool.cpp      | 11 ++---------
 src/txmempool.h        |  2 +-
 4 files changed, 5 insertions(+), 14 deletions(-)

diff --git a/src/rest.cpp b/src/rest.cpp
index 9c291fe0a..4a7101009 100644
--- a/src/rest.cpp
+++ b/src/rest.cpp
@@ -513,8 +513,7 @@ static bool rest_getutxos(HTTPRequest* req, const std::string& strURIPart)
             uint256 hash = vOutPoints[i].hash;
             bool hit = false;
             if (view.GetCoins(hash, coins)) {
-                mempool.pruneSpent(hash, coins);
-                if (coins.IsAvailable(vOutPoints[i].n)) {
+                if (coins.IsAvailable(vOutPoints[i].n) && !mempool.isSpent(vOutPoints[i])) {
                     hit = true;
                     // Safe to index into vout here because IsAvailable checked if it's off the end of the array, or if
                     // n is valid but points to an already spent output (IsNull).
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index e59b9b86b..94e42a864 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -973,9 +973,8 @@ UniValue gettxout(const JSONRPCRequest& request)
     if (fMempool) {
         LOCK(mempool.cs);
         CCoinsViewMemPool view(pcoinsTip, mempool);
-        if (!view.GetCoins(hash, coins))
+        if (!view.GetCoins(hash, coins) || mempool.isSpent(COutPoint(hash, n))) // TODO: this should be done by the CCoinsViewMemPool
             return NullUniValue;
-        mempool.pruneSpent(hash, coins); // TODO: this should be done by the CCoinsViewMemPool
     } else {
         if (!pcoinsTip->GetCoins(hash, coins))
             return NullUniValue;
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index 33df0536d..51b93e92b 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -343,17 +343,10 @@ CTxMemPool::CTxMemPool(CBlockPolicyEstimator* estimator) :
     nCheckFrequency = 0;
 }
 
-void CTxMemPool::pruneSpent(const uint256 &hashTx, CCoins &coins)
+bool CTxMemPool::isSpent(const COutPoint& outpoint)
 {
     LOCK(cs);
-
-    auto it = mapNextTx.lower_bound(COutPoint(hashTx, 0));
-
-    // iterate over all COutPoints in mapNextTx whose hash equals the provided hashTx
-    while (it != mapNextTx.end() && it->first->hash == hashTx) {
-        coins.Spend(it->first->n); // and remove those outputs from coins
-        it++;
-    }
+    return mapNextTx.count(outpoint);
 }
 
 unsigned int CTxMemPool::GetTransactionsUpdated() const
diff --git a/src/txmempool.h b/src/txmempool.h
index a91eb5be5..6547f64f7 100644
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -509,7 +509,7 @@ public:
     void _clear(); //lock free
     bool CompareDepthAndScore(const uint256& hasha, const uint256& hashb);
     void queryHashes(std::vector<uint256>& vtxid);
-    void pruneSpent(const uint256& hash, CCoins &coins);
+    bool isSpent(const COutPoint& outpoint);
     unsigned int GetTransactionsUpdated() const;
     void AddTransactionsUpdated(unsigned int n);
     /**