Avoid a double join alias when loading shared sidebar rooms

Chaining without_direct_rooms with with_ordered_room joined rooms as
`room` while still ordering on `rooms.name`. Load shared rooms in one
scope instead.

Co-authored-by: Thomas Klemm <github@tklemm.eu>

app/controllers/users/sidebars_controller.rb

@@ -4,7 +4,7 @@ class Users::SidebarsController < ApplicationController
   def show
     visible_memberships = Current.user.memberships.visible
     @direct_memberships = visible_memberships.with_direct_rooms
-    @other_memberships  = visible_memberships.without_direct_rooms.with_ordered_room
+    @other_memberships  = visible_memberships.with_ordered_shared_rooms
 
     @direct_placeholder_users = find_direct_placeholder_users
   end

app/models/membership.rb

@@ -10,6 +10,7 @@ class Membership < ApplicationRecord
 
   scope :with_ordered_room, -> { includes(:room).joins(:room).order("LOWER(rooms.name)") }
   scope :with_direct_rooms, -> { includes(:room).joins(:room).where(rooms: { type: "Rooms::Direct" }).order(rooms: { updated_at: :desc }) }
+  scope :with_ordered_shared_rooms, -> { includes(:room).joins(:room).where.not(rooms: { type: "Rooms::Direct" }).order("LOWER(rooms.name)") }
   scope :without_direct_rooms, -> { joins(:room).where.not(room: { type: "Rooms::Direct" }) }
 
   scope :visible, -> { where.not(involvement: :invisible) }