When a teacher (assume default role) ticks the " Delete all overrides in course" option on the Reset page are all overrides reset or only those overrides that are categorised as "Safe overrides"?
I am pretty sure it is all overrides.
Yes, the code is reset_course_userdata in lib.moodlelib.php is pretty clear.
Yes, the code is reset_course_userdata in lib.moodlelib.php is pretty clear.