Add description to MergeRequest model

app/models/concerns/issuable.rb

@@ -37,6 +37,8 @@ module Issuable
              prefix: true
     attr_accessor :author_id_of_changes
+
+    attr_mentionable :title, :description
   end
   module ClassMethods

app/models/issue.rb

@@ -32,7 +32,6 @@ class Issue < ActiveRecord::Base
   attr_accessible :title, :assignee_id, :position, :description,
                   :milestone_id, :label_list, :author_id_of_changes,
                   :state_event
-  attr_mentionable :title, :description
   acts_as_taggable_on :labels

app/models/merge_request.rb

@@ -30,8 +30,7 @@ class MergeRequest < ActiveRecord::Base
   belongs_to :target_project, foreign_key: :target_project_id, class_name: "Project"
   belongs_to :source_project, foreign_key: :source_project_id, class_name: "Project"
-  attr_accessible :title, :assignee_id, :source_project_id, :source_branch, :target_project_id, :target_branch, :milestone_id, :author_id_of_changes, :state_event
-  attr_mentionable :title
+  attr_accessible :title, :assignee_id, :source_project_id, :source_branch, :target_project_id, :target_branch, :milestone_id, :author_id_of_changes, :state_event, :description
   attr_accessor :should_remove_source_branch

db/migrate/20130909132950_add_description_to_merge_request.rb

+class AddDescriptionToMergeRequest < ActiveRecord::Migration
+  def change
+    add_column :merge_requests, :description, :text, null: true
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
-ActiveRecord::Schema.define(:version => 20130821090531) do
+ActiveRecord::Schema.define(:version => 20130909132950) do
   create_table "deploy_keys_projects", :force => true do |t|
     t.integer  "deploy_key_id", :null => false
@@ -100,6 +100,7 @@ ActiveRecord::Schema.define(:version => 20130821090531) do
     t.string   "merge_status"
     t.integer  "target_project_id",                       :null => false
     t.integer  "iid"
+    t.text     "description"
   end
   add_index "merge_requests", ["assignee_id"], :name => "index_merge_requests_on_assignee_id"