:autosave ignored on has_many relation -- what am I missing?
===

I have a pair of classes:

    class Collection < ActiveRecord::Base                                                                                                                                                                                                         
      attr_accessible :name
      has_many :items, autosave: true
    end

    class Item < ActiveRecord::Base
      attr_accessible :collection_id, :name
      belongs_to :collection
    end

From the [docs][1]:

> When :autosave is true all children is saved, no matter whether they are new records:

But when I update an `Item` and save its parent `Collection`, the `Item`'s upated attributes don't get saved:

    Loading development environment (Rails 3.2.5)
    1.9.2p320 :001 > c = Collection.first
      Collection Load (0.1ms)  SELECT "collections".* FROM "collections" LIMIT 1
     => #<Collection id: 1, name: "collection", created_at: "2012-07-23 00:00:10", updated_at: "2012-07-23 00:00:10"> 
    1.9.2p320 :002 > i = c.items.first
      Item Load (0.1ms)  SELECT "items".* FROM "items" WHERE "items"."collection_id" = 1 LIMIT 1
     => #<Item id: 1, collection_id: 1, name: "item1", created_at: "2012-07-23 00:00:25", updated_at: "2012-07-23 00:00:25"> 
    1.9.2p320 :003 > i.name = 'new name'
     => "new name" 
    1.9.2p320 :004 > c.save
       (0.1ms)  begin transaction
       (0.1ms)  commit transaction
     => true 
    1.9.2p320 :005 > Collection.first.items
      Collection Load (0.4ms)  SELECT "collections".* FROM "collections" LIMIT 1
      Item Load (0.2ms)  SELECT "items".* FROM "items" WHERE "items"."collection_id" = 1
     => [#<Item id: 1, collection_id: 1, name: "item1", created_at: "2012-07-23 00:00:25", updated_at: "2012-07-23 00:00:25">]

So, what am I missing?

I'm using Rails 3.2.5 and Ruby 1.9.2.

  [1]: http://api.rubyonrails.org/classes/ActiveRecord/AutosaveAssociation.html