Models should be equals even after destroyed

[#5978 state:committed]

activerecord/lib/active_record/base.rb

@@ -1585,9 +1585,9 @@ MSG
       # Returns true if the +comparison_object+ is the same object, or is of the same type and has the same id.
       def ==(comparison_object)
         comparison_object.equal?(self) ||
-          persisted? &&
-            (comparison_object.instance_of?(self.class) &&
-              comparison_object.id == id)
+          comparison_object.instance_of?(self.class) &&
+          id.present? &&
+          comparison_object.id == id
       end
 
       # Delegates to ==

activerecord/test/cases/base_test.rb

@@ -397,6 +397,15 @@ class BasicsTest < ActiveRecord::TestCase
     assert_not_equal Topic.new, Topic.new
   end
 
+  def test_equality_of_destroyed_records
+    topic_1 = Topic.new(:title => 'test_1')
+    topic_1.save
+    topic_2 = Topic.find(topic_1.id)
+    topic_1.destroy
+    assert_equal topic_1, topic_2
+    assert_equal topic_2, topic_1
+  end
+
   def test_hashing
     assert_equal [ Topic.find(1) ], [ Topic.find(2).topic ] & [ Topic.find(1) ]
   end

activerecord/test/cases/named_scope_test.rb

@@ -122,7 +122,7 @@ class NamedScopeTest < ActiveRecord::TestCase
       :joins => 'JOIN authors ON authors.id = posts.author_id',
       :conditions => [ 'authors.author_address_id = ?', address.id ]
     )
-    assert_equal posts_with_authors_at_address_titles, Post.with_authors_at_address(address).find(:all, :select => 'title')
+    assert_equal posts_with_authors_at_address_titles.map(&:title), Post.with_authors_at_address(address).find(:all, :select => 'title').map(&:title)
   end
 
   def test_scope_with_object