Merge pull request #389 from avbdr/master

fixes

MysqliDb.php

@@ -1731,7 +1731,7 @@ class MysqliDb
     public function copy()
     {
         $copy = unserialize(serialize($this));
-        $copy->_mysqli = $this->_mysqli;
+        $copy->_mysqli = null;
         return $copy;
     }
 

tests/mysqliDbTests.php

@@ -360,6 +360,8 @@ if ($c != 3) {
     echo "copy with subquery count failed";
     exit;
 }
+unset ($cnt);
+
 $data = $db->get('users');
 if (count($data) != 3) {
     echo "copy with subquery data count failed";