From 74d0f902628472cd0cee66121ef0311eec201c40 Mon Sep 17 00:00:00 2001
From: Matt Corallo <git@bluematt.me>
Date: Wed, 21 Oct 2015 17:41:40 -0700
Subject: [PATCH] Add method to remove a tx from CCoinsViewCache if it is
 unchanged

---
 src/coins.cpp | 9 +++++++++
 src/coins.h   | 6 ++++++
 2 files changed, 15 insertions(+)

diff --git a/src/coins.cpp b/src/coins.cpp
index 723e11470..060d6b7c5 100644
--- a/src/coins.cpp
+++ b/src/coins.cpp
@@ -206,6 +206,15 @@ bool CCoinsViewCache::Flush() {
     return fOk;
 }
 
+void CCoinsViewCache::Uncache(const uint256& hash)
+{
+    CCoinsMap::iterator it = cacheCoins.find(hash);
+    if (it != cacheCoins.end() && it->second.flags == 0) {
+        cachedCoinsUsage -= it->second.coins.DynamicMemoryUsage();
+        cacheCoins.erase(it);
+    }
+}
+
 unsigned int CCoinsViewCache::GetCacheSize() const {
     return cacheCoins.size();
 }
diff --git a/src/coins.h b/src/coins.h
index d17442210..5beea711b 100644
--- a/src/coins.h
+++ b/src/coins.h
@@ -437,6 +437,12 @@ public:
      */
     bool Flush();
 
+    /**
+     * Removes the transaction with the given hash from the cache, if it is
+     * not modified.
+     */
+    void Uncache(const uint256 &txid);
+
     //! Calculate the size of the cache (in number of transactions)
     unsigned int GetCacheSize() const;