Fixed :through relations when using STI inherited classes would use the inherited class's name as foreign key on the join model

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3315 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Fixed :through relations when using STI inherited classes would use the inherited class's name as foreign key on the join model [Tobias Luetke] 
+
 * MySQL: allow encoding option for mysql.rb driver.  [Jeremy Kemper]
 
 * Added option inheritance for find calls on has_and_belongs_to_many and has_many assosociations [DHH]. Example:

activerecord/lib/active_record/associations/has_many_through_association.rb

@@ -51,6 +51,7 @@ module ActiveRecord
 
         def construct_conditions
           through_reflection = @owner.class.reflections[@reflection.options[:through]]
+          through_foreign_classname = ActiveRecord::Base.send(:class_name_of_active_record_descendant, @owner.class).to_s
           
           if through_reflection.options[:as]
             conditions = 
@@ -60,7 +61,7 @@ module ActiveRecord
           else
             conditions = 
               "#{@reflection.klass.table_name}.#{@reflection.klass.primary_key} = #{through_reflection.table_name}.#{@reflection.klass.to_s.foreign_key} " +
-              "AND #{through_reflection.table_name}.#{@owner.class.to_s.foreign_key} = #{@owner.quoted_id}"
+              "AND #{through_reflection.table_name}.#{through_foreign_classname.foreign_key} = #{@owner.quoted_id}"
           end
           
           conditions << " AND (#{interpolate_sql(sanitize_sql(@reflection.options[:conditions]))})" if @reflection.options[:conditions]

activerecord/test/associations_join_model_test.rb

@@ -14,7 +14,15 @@ class AssociationsJoinModelTest < Test::Unit::TestCase
   def test_has_many
     assert_equal categories(:general), authors(:david).categories.first
   end
+  
+  def test_has_many_inherited
+    assert_equal categories(:sti_test), authors(:mary).categories.first
+  end
 
+  def test_inherited_has_many
+    assert_equal authors(:mary), categories(:sti_test).authors.first
+  end
+  
   def test_polymorphic_has_many
     assert_equal taggings(:welcome_general), posts(:welcome).taggings.first
   end
@@ -25,5 +33,10 @@ class AssociationsJoinModelTest < Test::Unit::TestCase
 
   def test_polymorphic_has_many_going_through_join_model
     assert_equal tags(:general), posts(:welcome).tags.first
-  end  
+  end
+  
+  def test_polymorphic_has_many_going_through_join_model_with_inheritance
+    assert_equal tags(:general), posts(:thinking).tags.first
+  end
+    
 end

activerecord/test/fixtures/categorizations.yml

@@ -2,4 +2,10 @@ david_welcome_general:
   id: 1
   author_id: 1
   post_id: 1
-  category_id: 1
+  category_id: 1
+  
+mary_thinking_sti:
+  id: 2
+  author_id: 2
+  post_id: 2
+  category_id: 3

activerecord/test/fixtures/category.rb

@@ -4,6 +4,9 @@ class Category < ActiveRecord::Base
   def self.what_are_you
     'a category...'
   end
+  
+  has_many :categorizations
+  has_many :authors, :through => :categorizations  
 end
 
 class SpecialCategory < Category

activerecord/test/fixtures/taggings.yml

@@ -3,3 +3,9 @@ welcome_general:
   tag_id: 1
   taggable_id: 1
   taggable_type: Post
+
+thinking_general:
+  id: 2
+  tag_id: 1
+  taggable_id: 2
+  taggable_type: Post

activerecord/test/fixtures/tags.yml

@@ -1,3 +1,7 @@
 general:
   id: 1
-  name: General
+  name: General
+  
+misc:
+  id: 2
+  name: Misc