Rails 4 unscope bug

example.rb

class Bar < ActiveRecord::Base
  default_scope -> { order(:name) }

  has_many :foos, through: :foo_bars
  has_many :foo_bars
end

class Foo < ActiveRecord::Base
  has_many :bars, -> { unscope(:order).order('foo_bars.sort') }, through: :foo_bars
  has_many :foo_bars
end

Foo.first.bars.to_sql

# Rails 4.0.0
# => SELECT "bars".* FROM "bars" INNER JOIN "foo_bars" ON "bars"."id" = "foo_bars"."bar_id" WHERE "foo_bars"."foo_id" = ?  ORDER BY "bars"."name" ASC, foo_bars.sort

# Rails 4.1.0.beta (master)
# => SELECT "bars".* FROM "bars" INNER JOIN "foo_bars" ON "bars"."id" = "foo_bars"."bar_id" WHERE "foo_bars"."foo_id" = ?  ORDER BY foo_bars.sort"