Fixed `where` for polymorphic associations when passed an array containing different types.

When passing in an array of different types of objects to `where`, it would only take into account the class of the first object in the array.

    PriceEstimate.where(estimate_of: [Treasure.find(1), Car.find(2)])
	# => SELECT "price_estimates".* FROM "price_estimates"
         WHERE ("price_estimates"."estimate_of_type" = 'Treasure' AND "price_estimates"."estimate_of_id" IN (1, 2))

This is fixed to properly look for any records matching both type and id:

    PriceEstimate.where(estimate_of: [Treasure.find(1), Car.find(2)])
    # => SELECT "price_estimates".* FROM "price_estimates"
         WHERE (("price_estimates"."estimate_of_type" = 'Treasure' AND "price_estimates"."estimate_of_id" = 1)
         OR ("price_estimates"."estimate_of_type" = 'Car' AND "price_estimates"."estimate_of_id" = 2))

1 files changed, 2 insertions, 0 deletions

diff --git a/activerecord/test/models/car.rb b/activerecord/test/models/car.rb
index 778c22b1f6..0f37e9a289 100644
--- a/activerecord/test/models/car.rb
+++ b/activerecord/test/models/car.rb
@@ -12,6 +12,8 @@ class Car < ActiveRecord::Base
   has_many :engines, :dependent => :destroy, inverse_of: :my_car
   has_many :wheels, :as => :wheelable, :dependent => :destroy
 
+  has_many :price_estimates, :as => :estimate_of
+
   scope :incl_tyres, -> { includes(:tyres) }
   scope :incl_engines, -> { includes(:engines) }