Fix course/teacher update see BT#10216

main/admin/course_edit.php

@@ -359,7 +359,6 @@ if ($form->validate()) {
     // Updating teachers
 
     if ($addTeacherToSessionCourses) {
-
         // Updating session coaches
         $sessionCoaches = $course['session_coaches'];
         if (!empty($sessionCoaches)) {
@@ -374,7 +373,7 @@ if ($form->validate()) {
             }
         }
 
-        CourseManager::updateTeachers($courseId, $teachers, false, true, false);
+        CourseManager::updateTeachers($courseId, $teachers, true, true, false);
     } else {
         // Normal behaviour
         CourseManager::updateTeachers($courseId, $teachers, true, false);

main/inc/lib/course.lib.php

@@ -4829,7 +4829,7 @@ class CourseManager
             }
 
             $sql = 'DELETE FROM ' . $course_user_table . '
-                    WHERE c_id ="' . $courseId . '" AND status="1"' . $cond;
+                    WHERE c_id ="' . $courseId . '" AND status="1" AND relation_type = 0 ' . $cond;
             Database::query($sql);
         }
 
@@ -4850,6 +4850,7 @@ class CourseManager
                             status = '1',
                             is_tutor = '0',
                             sort = '0',
+                            relation_type = '0',
                             user_course_cat='0'";
                 }
                 Database::query($sql);