4 files changed, 15 insertions, 12 deletions
diff --git a/activerecord/test/cases/counter_cache_test.rb b/activerecord/test/cases/counter_cache_test.rb
index 1f5055b2a2..922cb59280 100644
--- a/activerecord/test/cases/counter_cache_test.rb
+++ b/activerecord/test/cases/counter_cache_test.rb
@@ -1,6 +1,7 @@
 require 'cases/helper'
 require 'models/topic'
 require 'models/car'
+require 'models/aircraft'
 require 'models/wheel'
 require 'models/engine'
 require 'models/reply'
@@ -198,4 +199,16 @@ class CounterCacheTest < ActiveRecord::TestCase
     assert_equal 2, car.engines_count
     assert_equal 2, car.reload.engines_count
   end
+
+  test "update counters in a polymorphic relationship" do
+    aircraft = Aircraft.create!
+
+    assert_difference 'aircraft.reload.wheels_count' do
+      aircraft.wheels << Wheel.create!
+    end
+
+    assert_difference 'aircraft.reload.wheels_count', -1 do
+      aircraft.wheels.first.destroy
+    end
+  end
 end
diff --git a/activerecord/test/cases/locking_test.rb b/activerecord/test/cases/locking_test.rb
index dbdcc84b7d..839bbea5bb 100644
--- a/activerecord/test/cases/locking_test.rb
+++ b/activerecord/test/cases/locking_test.rb
@@ -263,18 +263,6 @@ class OptimisticLockingTest < ActiveRecord::TestCase
     end
   end
 
-  def test_polymorphic_destroy_with_dependencies_and_lock_version
-    car = Car.create!
-
-    assert_difference 'car.wheels.count'  do
-      car.wheels << Wheel.create!
-    end
-    assert_difference 'car.wheels.count', -1  do
-      car.destroy
-    end
-    assert car.destroyed?
-  end
-
   def test_removing_has_and_belongs_to_many_associations_upon_destroy
     p = RichPerson.create! first_name: 'Jon'
     p.treasures.create!
diff --git a/activerecord/test/models/aircraft.rb b/activerecord/test/models/aircraft.rb
index 1f35ef45da..c4404a8094 100644
--- a/activerecord/test/models/aircraft.rb
+++ b/activerecord/test/models/aircraft.rb
@@ -1,4 +1,5 @@
 class Aircraft < ActiveRecord::Base
   self.pluralize_table_names = false
   has_many :engines, :foreign_key => "car_id"
+  has_many :wheels, as: :wheelable
 end
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index 2fc806f181..7bab675b2a 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -37,6 +37,7 @@ ActiveRecord::Schema.define do
 
   create_table :aircraft, force: true do |t|
     t.string :name
+    t.integer :wheels_count, default: 0, null: false
   end
 
   create_table :articles, force: true do |t|