add test to compare sql statements in delete_all query

delete_all sql if an association is not loaded should behave
the same as if the association is loaded. This test ensures
the SQL statements are exactly the same.

activerecord/test/cases/associations/has_many_associations_test.rb

@@ -22,6 +22,8 @@
 require 'models/categorization'
 require 'models/minivan'
 require 'models/speedometer'
+require 'models/reference'
+require 'models/job'
 
 class HasManyAssociationsTestForReorderWithJoinDependency < ActiveRecord::TestCase
   fixtures :authors, :posts, :comments
@@ -39,7 +41,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   fixtures :accounts, :categories, :companies, :developers, :projects,
            :developers_projects, :topics, :authors, :comments,
            :people, :posts, :readers, :taggings, :cars, :essays,
-           :categorizations
+           :categorizations, :jobs
 
   def setup
     Client.destroyed_client_ids.clear
@@ -107,6 +109,19 @@ def test_do_not_call_callbacks_for_delete_all
     assert_equal 0, Bulb.count, "bulbs should have been deleted using :delete_all strategy"
   end
 
+  def test_delete_all_on_association_is_the_same_as_not_loaded
+    author = authors :david
+    author.thinking_posts.create!(:body => "test")
+    author.reload
+    expected_sql = capture_sql { author.thinking_posts.delete_all }
+
+    author.thinking_posts.create!(:body => "test")
+    author.reload
+    author.thinking_posts.inspect
+    loaded_sql = capture_sql { author.thinking_posts.delete_all }
+    assert_equal(expected_sql, loaded_sql)
+  end
+
   def test_building_the_associated_object_with_implicit_sti_base_class
     firm = DependentFirm.new
     company = firm.companies.build