From 72aee6b2c1959a9486bc6e324640445147cbad1d Mon Sep 17 00:00:00 2001
From: danielgrippi <danielgrippi@gmail.com>
Date: Tue, 24 Jan 2012 23:47:45 -0800
Subject: [PATCH] don't use .last(3), use .limit(3) instead.  also, don't put
 an order on an association as it isn't overridable.  (this commit minimizes
 AR object instantiation in the stream)

---
 app/models/post.rb          | 4 +++-
 lib/diaspora/commentable.rb | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/app/models/post.rb b/app/models/post.rb
index dc656e672..2657df5ba 100644
--- a/app/models/post.rb
+++ b/app/models/post.rb
@@ -67,7 +67,9 @@ class Post < ActiveRecord::Base
   # gives the last three comments on the post
   def last_three_comments
     return if self.comments_count == 0
-    self.comments.includes(:author => :profile).last(3)
+    # DO NOT USE .last(3) HERE.  IT WILL FETCH ALL COMMENTS AND RETURN THE LAST THREE
+    # INSTEAD OF DOING THE FOLLOWING, AS EXPECTED (THX AR):
+    self.comments.order('created_at DESC').limit(3).includes(:author => :profile).reverse!
   end
 
   def self.excluding_blocks(user)
diff --git a/lib/diaspora/commentable.rb b/lib/diaspora/commentable.rb
index 54f3bc0d7..a603c1835 100644
--- a/lib/diaspora/commentable.rb
+++ b/lib/diaspora/commentable.rb
@@ -6,7 +6,7 @@ module Diaspora
   module Commentable
     def self.included(model)
       model.instance_eval do
-        has_many :comments, :as => :commentable, :order => 'created_at', :dependent => :destroy
+        has_many :comments, :as => :commentable, :dependent => :destroy
       end
     end