Fix polymorphic has_one associations declared in an abstract class. Closes #8638.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7119 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

 *SVN*
 
+* Fix polymorphic has_one associations declared in an abstract class.  #8638 [lifofifo, daxhuiberts]
+
 * Fixed validates_associated should not stop on the first error #4276 [mrj/manfred/josh]
 
 * Rollback if commit raises an exception.  #8642 [kik, Jeremy Kemper]

activerecord/lib/active_record/associations.rb

@@ -1681,7 +1681,7 @@ def association_join
                         as_extra
                       ]
 
-                    when reflection.macro == :has_many && reflection.options[:as]
+                    when reflection.options[:as] && [:has_many, :has_one].include?(reflection.macro)
                       " LEFT OUTER JOIN %s ON %s.%s = %s.%s AND %s.%s = %s" % [
                         table_name_and_alias,
                         aliased_table_name, "#{reflection.options[:as]}_id",
@@ -1689,14 +1689,6 @@ def association_join
                         aliased_table_name, "#{reflection.options[:as]}_type",
                         klass.quote_value(parent.active_record.base_class.name)
                       ]
-                    when reflection.macro == :has_one && reflection.options[:as]
-                      " LEFT OUTER JOIN %s ON %s.%s = %s.%s AND %s.%s = %s " % [
-                        table_name_and_alias,
-                        aliased_table_name, "#{reflection.options[:as]}_id",
-                        parent.aliased_table_name, parent.primary_key,
-                        aliased_table_name, "#{reflection.options[:as]}_type",
-                        klass.quote_value(reflection.active_record.base_class.name)
-                      ]
                     else
                       foreign_key = options[:foreign_key] || reflection.active_record.name.foreign_key
                       " LEFT OUTER JOIN %s ON %s.%s = %s.%s " % [

activerecord/test/associations/join_model_test.rb

@@ -2,6 +2,7 @@
 require 'fixtures/tag'
 require 'fixtures/tagging'
 require 'fixtures/post'
+require 'fixtures/item'
 require 'fixtures/comment'
 require 'fixtures/author'
 require 'fixtures/category'
@@ -11,7 +12,7 @@
 
 class AssociationsJoinModelTest < Test::Unit::TestCase
   self.use_transactional_fixtures = false
-  fixtures :posts, :authors, :categories, :categorizations, :comments, :tags, :taggings, :author_favorites, :vertices
+  fixtures :posts, :authors, :categories, :categorizations, :comments, :tags, :taggings, :author_favorites, :vertices, :items
 
   def test_has_many
     assert authors(:david).categories.include?(categories(:general))
@@ -229,7 +230,15 @@ def test_include_polymorphic_has_one
       assert_equal tagging, post.tagging
     end
   end
-
+  
+  def test_include_polymorphic_has_one_defined_in_abstract_parent
+    item    = Item.find_by_id(items(:dvd).id, :include => :tagging)
+    tagging = taggings(:godfather)
+    assert_no_queries do
+      assert_equal tagging, item.tagging
+    end
+  end
+  
   def test_include_polymorphic_has_many_through
     posts           = Post.find(:all, :order => 'posts.id')
     posts_with_tags = Post.find(:all, :include => :tags, :order => 'posts.id')

activerecord/test/fixtures/db_definitions/schema.rb

@@ -57,6 +57,10 @@ def create_table(*args, &block)
   create_table :lock_without_defaults_cust, :force => true do |t|
     t.column :custom_lock_version, :integer
   end
+  
+  create_table :items, :force => true do |t|
+    t.column :name, :integer
+  end
 
   # For sqlite 3.1.0+, make a table with a autoincrement column
   if adapter_name == 'SQLite' and supports_autoincrement?

activerecord/test/fixtures/item.rb

+class AbstractItem < ActiveRecord::Base
+  self.abstract_class = true
+  has_one :tagging, :as => :taggable
+end
+
+class Item < AbstractItem
+end

activerecord/test/fixtures/items.yml

+dvd:
+  id: 1
+  name: Godfather
+  
\ No newline at end of file

activerecord/test/fixtures/taggings.yml

@@ -15,4 +15,11 @@ fake:
   id: 3
   tag_id: 1
   taggable_id: 1
-  taggable_type: FakeModel
\ No newline at end of file
+  taggable_type: FakeModel
+
+godfather:
+  id: 4
+  tag_id: 1
+  taggable_id: 1
+  taggable_type: Item
+  
\ No newline at end of file