has_many :through association writer is gone?

Hi,

I have an app running on revision 8431 and today updated Rails to the very edge. Application has the following models:

class Account < ActiveRecord::Base
   has_many :roles, :through => :role_memberships
   has_many :role_memberships
end

class Role < ActiveRecord::Base
   has_many :accounts, :through => :role_memberships
   has_many :role_memberships
end

class RoleMembership < ActiveRecord::Base
   belongs_to :role
   belongs_to :account
end

class Provider < Account
end

After update my specs start failing with the following exception:

undefined method `roles=' for #<Provider:0x2174df8>

I noticed that the only changeset that affected creation of HM :through association is this (line 672):

http://dev.rubyonrails.org/changeset?old=trunk%2Factiverecord%2Flib%2Factive_record%2Fassociations.rb%408481&new=trunk%2Factiverecord%2Flib%2Factive_record%2Fassociations.rb%408456

So has_many :through has no longer writer method. Though, collection_reader_method used before that changeset states that only reader should be created.

Is this an intentional behaviour from now on, am I missing the way Provider model had roles= method or any other thoughts?

Thanks.

MK