Implement CTransaction::IsEquivalentTo(...)

Define CTransaction::IsEquivalentTo(const CTransaction& tx)

True if only scriptSigs are different.  In other words, true if
the two transactions are malleability clones.  In other words,
true if the two transactions have the same effect on the
outside universe.

In the wallet, only SyncMetaData for equivalent transactions.

2 files changed, 12 insertions, 0 deletions

diff --git a/src/primitives/transaction.cpp b/src/primitives/transaction.cpp
index 606dbea798..d864a9b6d3 100644
--- a/src/primitives/transaction.cpp
+++ b/src/primitives/transaction.cpp
@@ -87,6 +87,15 @@ CTransaction& CTransaction::operator=(const CTransaction &tx) {
     return *this;
 }
 
+bool CTransaction::IsEquivalentTo(const CTransaction& tx) const
+{
+	CMutableTransaction tx1 = *this;
+	CMutableTransaction tx2 = tx;
+	for (unsigned int i = 0; i < tx1.vin.size(); i++) tx1.vin[i].scriptSig = CScript();
+	for (unsigned int i = 0; i < tx2.vin.size(); i++) tx2.vin[i].scriptSig = CScript();
+	return CTransaction(tx1) == CTransaction(tx2);
+}
+
 CAmount CTransaction::GetValueOut() const
 {
     CAmount nValueOut = 0;
diff --git a/src/primitives/transaction.h b/src/primitives/transaction.h
index 6cfd93a9a1..0c9ebb7b88 100644
--- a/src/primitives/transaction.h
+++ b/src/primitives/transaction.h
@@ -222,6 +222,9 @@ public:
         return hash;
     }
 
+    // True if only scriptSigs are different
+    bool IsEquivalentTo(const CTransaction& tx) const;
+
     // Return sum of txouts.
     CAmount GetValueOut() const;
     // GetValueIn() is a method on CCoinsViewCache, because