From 4b5977aa6a3b0ccd67efd92c8d319ba99dca30fa Mon Sep 17 00:00:00 2001
From: Robin Ward <robin.ward@gmail.com>
Date: Wed, 28 Mar 2018 15:35:13 -0400
Subject: [PATCH] Revert "PERF: Don't join on shared drafts unless you have to"

This reverts commit efedd9745fd9c34ac982941cca79f8ab8e517328.
---
 app/controllers/list_controller.rb            |  5 +---
 app/models/topic_list.rb                      | 27 +++++++++----------
 app/serializers/topic_list_item_serializer.rb |  5 +---
 app/serializers/topic_list_serializer.rb      | 18 ++-----------
 lib/topic_query.rb                            | 14 +++++-----
 5 files changed, 22 insertions(+), 47 deletions(-)

diff --git a/app/controllers/list_controller.rb b/app/controllers/list_controller.rb
index 4971861a657..659e66f008a 100644
--- a/app/controllers/list_controller.rb
+++ b/app/controllers/list_controller.rb
@@ -71,10 +71,7 @@ class ListController < ApplicationController
 
       list = TopicQuery.new(user, list_opts).public_send("list_#{filter}")
 
-      if @category.present? &&
-        guardian.can_create_shared_draft? &&
-        @category.id != SiteSetting.shared_drafts_category.to_i
-
+      if @category.present? && guardian.can_create_shared_draft?
         shared_drafts = TopicQuery.new(
           user,
           category: SiteSetting.shared_drafts_category,
diff --git a/app/models/topic_list.rb b/app/models/topic_list.rb
index 5aae90f7782..6de3eafcbe6 100644
--- a/app/models/topic_list.rb
+++ b/app/models/topic_list.rb
@@ -26,21 +26,18 @@ class TopicList
     end
   end
 
-  attr_accessor(
-    :more_topics_url,
-    :prev_topics_url,
-    :draft,
-    :draft_key,
-    :draft_sequence,
-    :filter,
-    :for_period,
-    :per_page,
-    :top_tags,
-    :current_user,
-    :tags,
-    :shared_drafts,
-    :category
-  )
+  attr_accessor :more_topics_url,
+                :prev_topics_url,
+                :draft,
+                :draft_key,
+                :draft_sequence,
+                :filter,
+                :for_period,
+                :per_page,
+                :top_tags,
+                :current_user,
+                :tags,
+                :shared_drafts
 
   def initialize(filter, current_user, topics, opts = nil)
     @filter = filter
diff --git a/app/serializers/topic_list_item_serializer.rb b/app/serializers/topic_list_item_serializer.rb
index a4544374349..663cc2c9a26 100644
--- a/app/serializers/topic_list_item_serializer.rb
+++ b/app/serializers/topic_list_item_serializer.rb
@@ -1,8 +1,6 @@
 class TopicListItemSerializer < ListableTopicSerializer
   include TopicTagsMixin
 
-  attr_accessor :include_destination_category
-
   attributes :views,
              :like_count,
              :has_summary,
@@ -32,9 +30,8 @@ class TopicListItemSerializer < ListableTopicSerializer
   end
 
   def category_id
-
     # If it's a shared draft, show the destination topic instead
-    if include_destination_category && object.shared_draft
+    if object.category_id == SiteSetting.shared_drafts_category.to_i && object.shared_draft
       return object.shared_draft.category_id
     end
 
diff --git a/app/serializers/topic_list_serializer.rb b/app/serializers/topic_list_serializer.rb
index f6dd513bf36..6ee27854ca8 100644
--- a/app/serializers/topic_list_serializer.rb
+++ b/app/serializers/topic_list_serializer.rb
@@ -9,26 +9,12 @@ class TopicListSerializer < ApplicationSerializer
              :per_page,
              :top_tags,
              :tags,
-             :shared_drafts,
-             :topics
+             :shared_drafts
 
+  has_many :topics, serializer: TopicListItemSerializer, embed: :objects
   has_many :shared_drafts, serializer: TopicListItemSerializer, embed: :objects
   has_many :tags, serializer: TagSerializer, embed: :objects
 
-  def topics
-    object.topics.map do |t|
-      serializer = TopicListItemSerializer.new(t, scope: scope, root: false)
-
-      if scope.can_create_shared_draft? &&
-        object.category&.id == SiteSetting.shared_drafts_category.to_i
-
-        serializer.include_destination_category = true
-      end
-
-      serializer
-    end
-  end
-
   def can_create_topic
     scope.can_create?(Topic)
   end
diff --git a/lib/topic_query.rb b/lib/topic_query.rb
index 563eedf67a0..a6cbacf3f49 100644
--- a/lib/topic_query.rb
+++ b/lib/topic_query.rb
@@ -482,19 +482,17 @@ class TopicQuery
     end
 
     def apply_shared_drafts(result, category_id, options)
-      drafts_category_id = SiteSetting.shared_drafts_category.to_i
-      viewing_shared = category_id && category_id == drafts_category_id
+      viewing_shared = category_id && category_id == SiteSetting.shared_drafts_category.to_i
 
       if guardian.can_create_shared_draft?
+        result = result.includes(:shared_draft).references(:shared_draft)
+
         if options[:destination_category_id]
           destination_category_id = get_category_id(options[:destination_category_id])
-          topic_ids = SharedDraft.where(category_id: destination_category_id).pluck(:topic_id)
-          return result.where(id: topic_ids)
-        elsif viewing_shared
-          result = result.includes(:shared_draft).references(:shared_draft)
-        else
-          return result.where('topics.category_id != ?', drafts_category_id)
+          return result.where("shared_drafts.category_id" => destination_category_id)
         end
+
+        return result.where("shared_drafts.id IS NULL") unless viewing_shared
       end
 
       result