correct calls to StructualElement::canRead(), fixes #4815

Closes #4815

Merge request studip/studip!3605

app/controllers/courseware/lti.php

@@ -11,7 +11,7 @@ class Courseware_LtiController extends AuthenticatedController
     public function iframe_action($block_id)
     {
         $cw_block = \Courseware\Block::find($block_id);
-        if (!$cw_block->container->structural_element->canRead($GLOBALS['user']->id)) {
+        if (!$cw_block->container->structural_element->canRead(User::findCurrent())) {
             throw new AccessDeniedException();
         }
 

lib/classes/globalsearch/GlobalSearchCourseware.php

@@ -118,7 +118,7 @@ class GlobalSearchCourseware extends GlobalSearchModule implements GlobalSearchF
     {
         $structural_element = StructuralElement::find($data['id']);
         $unit = $structural_element->findUnit();
-        if ($unit && $structural_element->canRead($GLOBALS['user'])) {
+        if ($unit && $structural_element->canRead(User::findCurrent())) {
             $description = '';
             if ($data['type'] === 'cw_structural_elements') {
                 $description = self::mark($structural_element->payload['description'], $search, true);