PERF: N+1 query in search when plugin loads custom fields in TopicListItemSerializer.

app/serializers/search_post_serializer.rb

@@ -1,5 +1,5 @@
 class SearchPostSerializer < BasicPostSerializer
-  has_one :topic, serializer: TopicListItemSerializer
+  has_one :topic, serializer: SearchTopicListItemSerializer
 
   attributes :like_count, :blurb, :post_number
 

app/serializers/search_topic_list_item_serializer.rb

@@ -0,0 +1,12 @@
+class SearchTopicListItemSerializer < ListableTopicSerializer
+  attributes :tags,
+    :category_id
+
+  def include_tags?
+    SiteSetting.tagging_enabled
+  end
+
+  def tags
+    object.tags.map(&:name)
+  end
+end