From 0b9e9dca4e88e41f7dae4fd9cd8e0f93fabafe01 Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter.wuille@gmail.com>
Date: Fri, 30 Oct 2015 23:38:40 +0100
Subject: [PATCH] Evict sigcache entries that are seen in a block

---
 src/script/sigcache.cpp | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/script/sigcache.cpp b/src/script/sigcache.cpp
index 9dc7f0fcd5..eee96e7c2d 100644
--- a/src/script/sigcache.cpp
+++ b/src/script/sigcache.cpp
@@ -62,6 +62,12 @@ public:
         return setValid.count(entry);
     }
 
+    void Erase(const uint256& entry)
+    {
+        boost::unique_lock<boost::shared_mutex> lock(cs_sigcache);
+        setValid.erase(entry);
+    }
+
     void Set(const uint256& entry)
     {
         size_t nMaxCacheSize = GetArg("-maxsigcachesize", DEFAULT_MAX_SIG_CACHE_SIZE) * ((size_t) 1 << 20);
@@ -90,13 +96,18 @@ bool CachingTransactionSignatureChecker::VerifySignature(const std::vector<unsig
     uint256 entry;
     signatureCache.ComputeEntry(entry, sighash, vchSig, pubkey);
 
-    if (signatureCache.Get(entry))
+    if (signatureCache.Get(entry)) {
+        if (!store) {
+            signatureCache.Erase(entry);
+        }
         return true;
+    }
 
     if (!TransactionSignatureChecker::VerifySignature(vchSig, pubkey, sighash))
         return false;
 
-    if (store)
+    if (store) {
         signatureCache.Set(entry);
+    }
     return true;
 }