AlreadyHave(): only hold lock during mapTransactions access

src/main.cpp

@@ -2136,9 +2136,13 @@ bool static AlreadyHave(CTxDB& txdb, const CInv& inv)
     switch (inv.type)
     {
     case MSG_TX:
+        {
+	bool txInMap = false;
 	    {
             LOCK(cs_mapTransactions);
-        return mapTransactions.count(inv.hash) ||
+	    txInMap = (mapTransactions.count(inv.hash) != 0);
+	    }
+        return txInMap ||
                mapOrphanTransactions.count(inv.hash) ||
                txdb.ContainsTx(inv.hash);
         }