From a8085f15c4ccfb78fad1ab31ba41ecbddf104462 Mon Sep 17 00:00:00 2001
From: Sam Saffron <sam.saffron@gmail.com>
Date: Fri, 15 Feb 2013 12:58:14 +1100
Subject: [PATCH] grab highest post number from the raw data, so deletions at
 the end of a topic work

---
 app/serializers/topic_view_serializer.rb | 10 +++++++---
 lib/topic_view.rb                        |  9 +++++++++
 spec/components/topic_view_spec.rb       |  4 +++-
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/app/serializers/topic_view_serializer.rb b/app/serializers/topic_view_serializer.rb
index d5f64ee7358..003b15d7f54 100644
--- a/app/serializers/topic_view_serializer.rb
+++ b/app/serializers/topic_view_serializer.rb
@@ -5,7 +5,6 @@ class TopicViewSerializer < ApplicationSerializer
     [:id,
      :title,
      :posts_count,
-     :highest_post_number,
      :created_at,
      :views,
      :reply_count,
@@ -41,7 +40,8 @@ class TopicViewSerializer < ApplicationSerializer
              :notification_level,
              :notifications_reason_id,
              :posts,
-             :at_bottom
+             :at_bottom,
+             :highest_post_number
 
   has_one :created_by, serializer: BasicUserSerializer, embed: :objects
   has_one :last_poster, serializer: BasicUserSerializer, embed: :objects
@@ -185,7 +185,11 @@ class TopicViewSerializer < ApplicationSerializer
 
   # Whether we're at the bottom of a topic (last page)
   def at_bottom
-    posts.present? and (@highest_number_in_posts == object.topic.highest_post_number)
+    posts.present? and (@highest_number_in_posts == object.highest_post_number)
+  end
+
+  def highest_post_number
+    object.highest_post_number
   end
 
   def posts
diff --git a/lib/topic_view.rb b/lib/topic_view.rb
index e5ad0f5fdcc..fb84a680a77 100644
--- a/lib/topic_view.rb
+++ b/lib/topic_view.rb
@@ -223,6 +223,15 @@ class TopicView
     @suggested_topics ||= TopicQuery.new(@user).list_suggested_for(topic)
   end
 
+  # This is pending a larger refactor, that allows custom orders
+  #  for now we need to look for the highest_post_number in the stream 
+  #  the cache on topics is not correct if there are deleted posts at 
+  #  the end of the stream (for mods), nor is it correct for filtered 
+  #  streams
+  def highest_post_number
+    @highest_post_number ||= @posts.maximum(:post_number)
+  end
+
   protected
 
   def read_posts_set
diff --git a/spec/components/topic_view_spec.rb b/spec/components/topic_view_spec.rb
index ef6814330ab..41bf551185d 100644
--- a/spec/components/topic_view_spec.rb
+++ b/spec/components/topic_view_spec.rb
@@ -106,10 +106,12 @@ describe TopicView do
   end
 
   it 'allows admins to see deleted posts' do 
+    post_number = p3.post_number
     p3.destroy
     admin = Fabricate(:admin)
     topic_view = TopicView.new(topic.id, admin) 
     topic_view.posts.count.should == 3
+    topic_view.highest_post_number.should == post_number
   end
   
   it 'does not allow non admins to see deleted posts' do 
@@ -117,7 +119,7 @@ describe TopicView do
     topic_view.posts.count.should == 2
   end
 
-  # Sam: disabled for now, we only need this for poss, if we do, roll it into topic
+  # Sam: disabled for now, we only need this for polls, if we do, roll it into topic
   #  having to walk every post action is not really a good idea
   #
   # context '.voted_in_topic?' do