Fix(Order): Fix action to link an existing item (#529)

Author: stonebuzz

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Fix `Validation` tab from `Order`
 - Fix invalid relations declared
 - Fix uninstall method
+- Fix action to link an existing item
 
 ## [2.12.4] - 2025-12-02
 

inc/link.class.php

@@ -579,7 +579,7 @@ public static function processMassiveActionsForOneItemtype(
 
         // retrieve additional informations for each items
         $ma->POST['add_items'] = [];
-        if (isset($ma->items[self::class])) {
+        if (isset($ma->getItems()[self::class])) {
             $additional_data_ite = $DB->request([
                 'SELECT' => [
                     'glpi_plugin_order_orders_items.id',