Allow also to search in inactive groups.

app/controllers/tickets_controller.rb

@@ -116,12 +116,7 @@ class TicketsController < ApplicationController
     assets = ticket.assets({})
 
     # open tickets by customer
-    group_ids = Group.select('groups.id')
-                     .joins(:users)
-                     .where('groups_users.user_id = ?', current_user.id)
-                     .map(&:id)
-
-    access_condition = [ 'group_id IN (?)', group_ids ]
+    access_condition = Ticket.access_condition(current_user)
 
     ticket_lists = Ticket
                    .where(