Associated objects are assigned from identity map if enabled and contains associated object.

2 files changed, 23 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/associations/association_proxy.rb b/activerecord/lib/active_record/associations/association_proxy.rb
index 7cd04a1ad5..bfedffcf02 100644
--- a/activerecord/lib/active_record/associations/association_proxy.rb
+++ b/activerecord/lib/active_record/associations/association_proxy.rb
@@ -252,8 +252,11 @@ module ActiveRecord
         def load_target
           return nil unless defined?(@loaded)
 
-          if !loaded? and (@owner.persisted? || foreign_key_present)
-            @target = find_target
+          if !loaded? and (!@owner.persisted? || foreign_key_present)
+            if IdentityMap.enabled?
+              @target = IdentityMap.get(@reflection.class_name, @owner[@reflection.association_foreign_key])
+            end
+            @target ||= find_target
           end
 
           @loaded = true
diff --git a/activerecord/test/cases/identity_map_test.rb b/activerecord/test/cases/identity_map_test.rb
index 7deda56541..e62e99361a 100644
--- a/activerecord/test/cases/identity_map_test.rb
+++ b/activerecord/test/cases/identity_map_test.rb
@@ -287,4 +287,22 @@ class IdentityMapTest < ActiveRecord::TestCase
     assert_not_equal developer.salary, same_developer.salary
   end
 
+  def test_owner_object_is_associated_from_identity_map
+    post = Post.find(1)
+    comment = post.comments.first
+
+    assert_no_queries do
+      comment.post
+    end
+    assert_same post, comment.post
+  end
+
+  def test_associated_object_are_assigned_from_identity_map
+    post = Post.find(1)
+
+    post.comments.each do |comment|
+      assert_same post, comment.post
+      assert_equal post.object_id, comment.post.target.object_id
+    end
+  end
 end