autosave generates error when one-to-one association is empty after being accessed.

I'm not sure how best to phrase this issue, and it might ultimately be a problem with association proxies, but the problem I am seeing in Rails Edge (as of 2009-Feb-11) is visible when working with autosave. (Actually, I'm working with nested attributes, but they turn on autosave by default.) In a nutshell:

class Entity < ActiveRecord::Base
  has_one :person, :autosave => true
end
=> nil

class Person < ActiveRecord::Base
end
=> nil

e =  Entity.new
=> #<Entity id: nil, ... >

e.valid?
=> true

e.person
=> nil

e.valid?
NoMethodError: You have a nil object when you didn't expect it!
You might have expected an instance of Array.
The error occurred while evaluating nil.each
	from /home/placey/Development/tgrii/webapp/vendor/rails/activerecord/lib/active_record/autosave_association.rb:198:in `autosave_association_valid?'
	from /home/placey/Development/tgrii/webapp/vendor/rails/activesupport/lib/active_support/core_ext/object/misc.rb:39:in `returning'
	from /home/placey/Development/tgrii/webapp/vendor/rails/activerecord/lib/active_record/autosave_association.rb:197:in `autosave_association_valid?'
	from /home/placey/Development/tgrii/webapp/vendor/rails/activerecord/lib/active_record/autosave_association.rb:184:in `valid?'
	from (irb):64:in `all?'
	from /home/placey/Development/tgrii/webapp/vendor/rails/activerecord/lib/active_record/autosave_association.rb:179:in `each'
	from /home/placey/Development/tgrii/webapp/vendor/rails/activerecord/lib/active_record/autosave_association.rb:179:in `all?'
	from /home/placey/Development/tgrii/webapp/vendor/rails/activerecord/lib/active_record/autosave_association.rb:179:in `valid?'
	from (irb):64

In looking around (amateurishly) it seems the problem is that after accessing the 'person' association, the #loaded? method on the has_one association proxy is returning true even though nothing is loaded.

This sounds somewhat like this old issue: http://dev.rubyonrails.org/ticke...