revert ActiveRecord equality change. Closes #5596

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4554 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/lib/active_record/base.rb

@@ -1646,9 +1646,8 @@ def column_for_attribute(name)
       def ==(comparison_object)
         comparison_object.equal?(self) ||
           (comparison_object.instance_of?(self.class) && 
-            ((!comparison_object.new_record? && comparison_object.id == id) ||
-             (comparison_object.new_record? && comparison_object.attributes == attributes))
-          )
+            comparison_object.id == id && 
+            !comparison_object.new_record?)
       end
 
       # Delegates to ==