Revert "Merge pull request #9252 from senny/8423_hmt_preloading_bug"

This reverts commit c5451777b0.

Conflicts:
	activerecord/CHANGELOG.md

activerecord/CHANGELOG.md

@@ -1,27 +1,5 @@
 ## unreleased ##
 
-*   Preloading `has_many :through` associations with conditions won't
-    cache the `:through` association. This will prevent invalid
-    subsets to be cached.
-    Fixes #8423.
-
-    Example:
-
-        class User
-          has_many :posts
-          has_many :recent_comments, -> { where('created_at > ?', 1.week.ago) }, :through => :posts
-        end
-
-        a_user = User.includes(:recent_comments).first
-
-        # this is preloaded
-        a_user.recent_comments
-
-        # fetching the recent_comments through the posts association won't preload it.
-        a_user.posts
-
-    *Yves Senn*
-
 *   Fix counter cache columns not updated when replacing `has_many :through`
     associations.
     Backport #8400.

activerecord/lib/active_record/associations/preloader/through_association.rb

@@ -37,8 +37,7 @@ module ActiveRecord
             through_records = Array.wrap(owner.send(through_reflection.name))
 
             # Dont cache the association - we would only be caching a subset
-            if (through_scope != through_reflection.klass.unscoped) ||
-               (reflection.options[:source_type] && through_reflection.collection?)
+            if reflection.options[:source_type] && through_reflection.collection?
               owner.association(through_reflection.name).reset
             end
 

activerecord/test/cases/associations/eager_test.rb

@@ -1112,10 +1112,4 @@ class EagerAssociationTest < ActiveRecord::TestCase
       Post.includes(:comments).order(nil).where(:comments => {:body => "Thank you for the welcome"}).first
     end
   end
-
-  test "preloading does not cache has many association subset when preloaded with a through association" do
-    author = Author.includes(:comments_with_order_and_conditions, :posts).first
-    assert_no_queries { assert_equal 2, author.comments_with_order_and_conditions.size }
-    assert_no_queries { assert_equal 5, author.posts.size, "should not cache a subset of the association" }
-  end
 end