fixes #2362, eager loading :through associations will join the :sourc…

…e model if there are :conditions

Signed-off-by: José Valim <jose.valim@gmail.com>

activerecord/lib/active_record/association_preload.rb

@@ -282,7 +282,11 @@ def preload_through_records(records, reflection, through_association)
           end
           through_records.flatten!
         else
-          records.first.class.preload_associations(records, through_association)
+          options = {}
+          options[:include] = reflection.options[:include] || reflection.options[:source] if reflection.options[:conditions]
+          options[:order] = reflection.options[:order]
+          options[:conditions] = reflection.options[:conditions]
+          records.first.class.preload_associations(records, through_association, options)
           through_records = records.map {|record| record.send(through_association)}.flatten
         end
         through_records.compact!

activerecord/test/cases/associations/eager_test.rb

@@ -357,6 +357,13 @@ def test_eager_with_has_many_through_join_model_with_conditions_on_top_level
     assert_equal comments(:more_greetings), Author.find(authors(:david).id, :include => :comments_with_order_and_conditions).comments_with_order_and_conditions.first
   end
 
+  def test_eager_with_has_many_through_with_conditions_join_model_with_include
+    post_tags = Post.find(posts(:welcome).id).misc_tags
+    eager_post_tags = Post.find(1, :include => :misc_tags).misc_tags
+    assert_equal post_tags, eager_post_tags
+  end
+
+
   def test_eager_with_has_many_through_join_model_with_include
     author_comments = Author.find(authors(:david).id, :include => :comments_with_include).comments_with_include.to_a
     assert_no_queries do

activerecord/test/models/post.rb

@@ -53,6 +53,7 @@ def add_joins_and_select
     end
   end
 
+  has_many :misc_tags, :through => :taggings, :source => :tag, :conditions => "tags.name = 'Misc'"
   has_many :funky_tags, :through => :taggings, :source => :tag
   has_many :super_tags, :through => :taggings
   has_one :tagging, :as => :taggable