Button "Grade" in Activity Overview

If a student get the right for viewing gradings (mod/assign:grades), without the right grading submissions (mod/assign:grade)

Moodle shows the button grade now for the user.

If the student click on the button, he get some error message.

Solution:
Change source code in method "render_assign_grading_summary" in file mod/assign/renderer.php

Changes are green. The methode conside now the right "mod/assign:grade".

$context = context_module::instance($summary->coursemoduleid);
        if(has_capability('mod/assign:grade', $context)){
                $urlparams = array('id' => $summary->coursemoduleid, 'action' => 'grader');
                $url = new moodle_url('/mod/assign/view.php', $urlparams);
                $o .= '<a href="' . $url . '" class="btn btn-primary">' . get_string('grade') . '</a>';
       }