Remember last sort option used.

app/controllers/application_controller.rb

@@ -297,7 +297,8 @@ class ApplicationController < ActionController::Base
   end
   def set_filters_params
-    params[:sort] ||= 'id_desc'
+    set_default_sort
+
     params[:scope] = 'all' if params[:scope].blank?
     params[:state] = 'opened' if params[:state].blank?
@@ -404,4 +405,23 @@ class ApplicationController < ActionController::Base
     current_user.nil? && root_path == request.path
   end
+
+  private
+
+  def set_default_sort
+    controller_name = params[:controller].sub(/Controller\Z/, '').underscore
+    cookie_suffix = "_sort_#{controller_name}"
+
+    key = if @project
+            "#{@project.cookie_key}#{cookie_suffix}"
+          elsif @group
+            "#{@group.cookie_key}#{cookie_suffix}"
+          else
+            "#{current_user.cookie_key}#{cookie_suffix}"
+          end
+
+    cookies[key] ||= 'id_desc'
+    cookies[key] = params[:sort] if params[:sort].present?
+    params[:sort] = cookies[key]
+  end
 end

app/models/concerns/cookie_helpers.rb

+module CookieHelpers
+  def cookie_key
+    "#{model_name.singular}_#{id}"
+  end
+end

app/models/group.rb

@@ -19,6 +19,7 @@ require 'file_size_validator'
 class Group < Namespace
   include Gitlab::ConfigHelper
   include Referable
+  include CookieHelpers
   has_many :group_members, dependent: :destroy, as: :source, class_name: 'GroupMember'
   alias_method :members, :group_members

app/models/project.rb

@@ -51,6 +51,7 @@ class Project < ActiveRecord::Base
   include AfterCommitQueue
   include CaseSensitivity
   include TokenAuthenticatable
+  include CookieHelpers
   extend Gitlab::ConfigHelper

app/models/user.rb

@@ -73,6 +73,7 @@ class User < ActiveRecord::Base
   include Sortable
   include CaseSensitivity
   include TokenAuthenticatable
+  include CookieHelpers
   add_authentication_token_field :authentication_token