Without the patch, attempting to log in to a site that was not the first one in our list would take us to the first one in our list. The regular user account was sent to an unrelated subsite whereas the super admin account was sent to the root site. After the patch was applied, both accounts were redirected to the correct subsite. We tested reverting and reapplying the patch with the expected results: does not work without this patch, works with this patch.