Fix rails4 deprecation warnings

That appear when running topic_spec.rb

app/models/category.rb

@@ -1,9 +1,17 @@
 class Category < ActiveRecord::Base
   belongs_to :topic, dependent: :destroy
-  belongs_to :topic_only_relative_url,
+  if rails4?
+    belongs_to :topic_only_relative_url,
+    -> { select "id, title, slug" },
+    class_name: "Topic",
+    foreign_key: "topic_id"
+  else
+    belongs_to :topic_only_relative_url,
     select: "id, title, slug",
     class_name: "Topic",
     foreign_key: "topic_id"
+  end
+
   belongs_to :user
 
   has_many :topics

lib/topic_query.rb

@@ -212,23 +212,23 @@ class TopicQuery
       end
 
       result = result.listable_topics.includes(category: :topic_only_relative_url)
-      result = result.where('categories.name is null or categories.name <> ?', options[:exclude_category]) if options[:exclude_category]
-      result = result.where('categories.name = ?', options[:only_category]) if options[:only_category]
+      result = (rails4? ? result.where('categories.name is null or categories.name <> ?', options[:exclude_category]).references(:categories) : result.where('categories.name is null or categories.name <> ?', options[:exclude_category])) if options[:exclude_category]
+      result = (rails4? ? result.where('categories.name = ?', options[:only_category]).references(:categories) : result.where('categories.name = ?', options[:only_category])) if options[:only_category]
       result = result.limit(options[:per_page]) unless options[:limit] == false
       result = result.visible if options[:visible] || @user.nil? || @user.regular?
-      result = result.where('topics.id <> ?', options[:except_topic_id]) if options[:except_topic_id]
+      result = (rails4? ? result.where('topics.id <> ?', options[:except_topic_id]).references(:topics) : result.where('topics.id <> ?', options[:except_topic_id])) if options[:except_topic_id]
       result = result.offset(options[:page].to_i * options[:per_page]) if options[:page]
 
       if options[:topic_ids]
-        result = result.where('topics.id in (?)', options[:topic_ids])
+        result = rails4? ? result.where('topics.id in (?)', options[:topic_ids]).references(:topics) : result.where('topics.id in (?)', options[:topic_ids])
       end
 
       unless @user && @user.moderator?
         category_ids = @user.secure_category_ids if @user
         if category_ids.present?
-          result = result.where('categories.read_restricted IS NULL OR categories.read_restricted = ? OR categories.id IN (?)', false, category_ids)
+          result = rails4? ? result.where('categories.read_restricted IS NULL OR categories.read_restricted = ? OR categories.id IN (?)', false, category_ids).references(:categories) : result.where('categories.read_restricted IS NULL OR categories.read_restricted = ? OR categories.id IN (?)', false, category_ids)
         else
-          result = result.where('categories.read_restricted IS NULL OR categories.read_restricted = ?', false)
+          result = rails4? ? result.where('categories.read_restricted IS NULL OR categories.read_restricted = ?', false).references(:categories) : result.where('categories.read_restricted IS NULL OR categories.read_restricted = ?', false)
         end
       end
 

lib/trashable.rb

@@ -2,7 +2,7 @@ module Trashable
   extend ActiveSupport::Concern
 
   included do
-    default_scope where(with_deleted_scope_sql)
+    default_scope { where(with_deleted_scope_sql) }
 
     # scope unscoped does not work
     belongs_to :deleted_by, class_name: 'User'