Child association slug generation not triggered correctly

[glebm]

I have a case where a child association is created using standard rails accepts_nested_attributes. I tried making a test case, but couldn't get it running (don't understand where the table structure comes from).

class Company < ActiveRecord::Base
  has_many :job_ads

  extend FriendlyId
  friendly_id :slug_candidates, use: [:slugged, :history]

  def slug_candidates
    [:name, [:name, :summary]]
  end

  def should_generate_new_friendly_id?
    slug.blank? || name_changed?
  end
end

class JobAd < ActiveRecord::Base
  belongs_to :company
  accepts_nested_attributes_for :company

  extend FriendlyId
  friendly_id :slug_candidates, use: [:slugged, :history]

  def slug_candidates
    [:title, [:title, :company_name]]
  end

  def should_generate_new_friendly_id?
    slug.blank? || title_changed?
  end
end

class ChildAssociationTest < MiniTest::Unit::TestCase
  include FriendlyId::Test

  def test_child_association_slug
    JobAd.create!(
        title:              'Job A',
        company_attributes: {name: 'Apple Inc'}
    )
    JobAd.create!(
        title:              'Job B',
        company_attributes: {name: 'Apple Inc'}
    )
  end
end

The second create triggers a PG::UniqueViolation:

ERROR:  duplicate key value violates unique constraint "index_companies_on_slug"
DETAIL:  Key (slug)=(apple-inc) already exists.

How can I have it use a serial or a GUID for the second Apple Inc instead of blowing up? Thanks

Rails 4.0.1 and 4.0.2
friendly_id 5.0.1 and 5.0.2

[PikachuEXE]

Can you try not to use :history first to see if it works?
If it still failed then try #513