Optimization: Coin&& to ApplyTxInUndo

This avoids a prevector copy in ApplyTxInUndo.

src/test/coins_tests.cpp

@@ -17,7 +17,7 @@
 
 #include <boost/test/unit_test.hpp>
 
-int ApplyTxInUndo(const Coin& undo, CCoinsViewCache& view, const COutPoint& out);
+int ApplyTxInUndo(Coin&& undo, CCoinsViewCache& view, const COutPoint& out);
 void UpdateCoins(const CTransaction& tx, CCoinsViewCache& inputs, CTxUndo &txundo, int nHeight);
 
 namespace
@@ -371,8 +371,8 @@ BOOST_AUTO_TEST_CASE(updatecoins_simulation_test)
             // restore inputs
             if (!tx.IsCoinBase()) {
                 const COutPoint &out = tx.vin[0].prevout;
-                const Coin &undoin = undo.vprevout[0];
-                ApplyTxInUndo(undoin, *(stack.back()), out);
+                Coin coin = undo.vprevout[0];
+                ApplyTxInUndo(std::move(coin), *(stack.back()), out);
             }
             // Store as a candidate for reconnection
             disconnectedids.insert(undohash);