Forum render doesn't handle deleted user without context

This test requires access to the database Log in as admin Create a site with 2 users Create a course and enrol the 2 users Create a forum activity in the course Create 2 discussion in the course as the admin user Log in as user 1 View the forum and add a reply to one of the admin discussions Create a separate discussion in the forum Log in as user 2 View the forum and add a reply to the other admin discussion (the one that user 1 didn't reply in) Create a separate discussion in the forum There should now be 4 discussions in the forum Created by admin with user 1 posting in it Created by admin with user 2 postint in it Created by user 1 Created by user 2 Log in as admin Go to site administration and delete both user 1 and user 2 Log in to the database Delete the record for user 2 from the context table You can find it by doing SELECT * FROM "<context_table>" WHERE contextlevel = 30 AND instanceid = <user_2_id> View the forum CONFIRM the list of discussions show even though both users are deleted and user 2 has had their context deleted from the DB View each of the discussions CONFIRM that each discussion is rendered