Mongoid $or bug

gistfile1.rb

class Parent
  include Mongoid::Document
  field :pants
  field :shirts

  embeds_many :children
end

class Child
  include Mongoid::Document
  field :pants
  field :shirt

  embedded_in :parent
end


not_matching_child_1 = Child.new(:pants => 'red', :shirt => 'white')
not_matching_child_2 = Child.new(:pants => 'white', :shirt => 'red')
matching_child = Child.new(:pants => 'red', :shirt => 'red')
parent_with_children = Parent.create(:children => [not_matching_child_1, not_matching_child_2, matching_child])


not_matching_parent_1 = Parent.create(:pants => 'red', :shirt => 'white')
not_matching_parent_2 = Parent.create(:pants => 'white', :shirt => 'red')
matching_parent = Parent.create(:pants => 'red', :shirt => 'red')


# find non matching parents
Parent.where("$or" => [{:pants => 'red', :shirt => 'white'}, {:pants => 'white', :shirt => 'red'}]).count
#  => 2


# find non matching children
parent_with_children.children.where("$or" => [{:pants => 'red', :shirt => 'white'}, {:pants => 'white', :shirt => 'red'}]).count
#  => 3
# But should return 2!