app-functions-fn.cart.php.diff

diff --git a/app/functions/fn.cart.php b/app/functions/fn.cart.php
index 1e96c84..efa7eed 100644
--- a/app/functions/fn.cart.php
+++ b/app/functions/fn.cart.php
@@ -809,11 +810,19 @@ function fn_update_order(&$cart, $order_id = 0)
             $order['promotion_ids'] = fn_create_set(array_keys($cart['promotions']));
         }
 
-        $old_order = db_get_row("SELECT company_id, payment_id, status FROM ?:orders WHERE order_id = ?i", $order_id);
+        $old_order = db_get_row(
+            "SELECT company_id, payment_id, status, parent_order_id FROM ?:orders WHERE order_id = ?i",
+            $order_id
+        );
+
         $order['status']     = $old_order['status'];
         $order['company_id'] = $old_order['company_id'];
         $order_status        = $order['status'];
 
+        if (!isset($order['parent_order_id'])) {
+            $order['parent_order_id'] = $old_order['parent_order_id'];
+        }
+
         if (!empty($cart['payment_id']) && $cart['payment_id'] == $old_order['payment_id']) {
             $payment_info = db_get_field("SELECT data FROM ?:order_data WHERE order_id = ?i AND type = 'P'", $order_id);
             if (!empty($payment_info)) {
@@ -1073,6 +1082,10 @@ function fn_update_order_data($order_id, $cart)
  */
 function fn_place_order(&$cart, &$auth, $action = '', $issuer_id = null, $parent_order_id = 0)
 {
+    if (isset($cart['parent_order_id']) && empty($parent_order_id)) {
+        $parent_order_id = (int)$cart['parent_order_id'];
+    }
+
     $allow = fn_allow_place_order($cart, $auth);
 
     fn_set_hook('pre_place_order', $cart, $allow, $cart['product_groups']);
@@ -4724,6 +4737,7 @@ function fn_form_cart($order_id, &$cart, &$auth)
         Storage::instance('custom_files')->copy($dir_path, 'sess_data');
     }
 
+    $cart['parent_order_id'] = $order_info['parent_order_id'];
     $cart['payment_id'] = $order_info['payment_id'];
     $cart['stored_taxes'] = 'Y';
     $cart['stored_discount'] = 'Y';