Allow reply-by-email with diff notes

app/models/sent_notification.rb

 class SentNotification < ActiveRecord::Base
+  serialize :position, Gitlab::Diff::Position
+
   belongs_to :project
   belongs_to :noteable, polymorphic: true
   belongs_to :recipient, class_name: "User"
@@ -7,7 +9,7 @@ class SentNotification < ActiveRecord::Base
   validates :reply_key, uniqueness: true
   validates :noteable_id, presence: true, unless: :for_commit?
   validates :commit_id, presence: true, if: :for_commit?
-  validates :line_code, line_code: true, allow_blank: true
+  validate :note_valid
 
   after_save :keep_around_commit
 
@@ -74,8 +76,33 @@ class SentNotification < ActiveRecord::Base
     self.reply_key
   end
 
+  def note_attributes
+    {
+      project:        self.project,
+      author:         self.recipient,
+      type:           self.note_type,
+      noteable_type:  self.noteable_type,
+      noteable_id:    self.noteable_id,
+      commit_id:      self.commit_id,
+      line_code:      self.line_code,
+      position:       self.position.to_json
+    }
+  end
+
+  def create_note(note)
+    Notes::CreateService.new(
+      self.project,
+      self.recipient,
+      self.note_attributes.merge(note: note)
+    ).execute
+  end
+
   private
 
+  def note_valid
+    Note.new(note_attributes.merge(note: "Test")).valid?
+  end
+
   def keep_around_commit
     project.repository.keep_around(self.commit_id)
   end

db/migrate/20160522215720_add_note_type_and_position_to_sent_notification.rb

+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class AddNoteTypeAndPositionToSentNotification < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  # When using the methods "add_concurrent_index" or "add_column_with_default"
+  # you must disable the use of transactions as these methods can not run in an
+  # existing transaction. When using "add_concurrent_index" make sure that this
+  # method is the _only_ method called in the migration, any other changes
+  # should go in a separate migration. This ensures that upon failure _only_ the
+  # index creation fails and can be retried or reverted easily.
+  #
+  # To disable transactions uncomment the following line and remove these
+  # comments:
+  # disable_ddl_transaction!
+
+  def change
+    add_column :sent_notifications, :note_type, :string
+    add_column :sent_notifications, :position, :text
+  end
+end

lib/gitlab/email/receiver.rb

@@ -104,15 +104,7 @@ module Gitlab
       end
 
       def create_note(reply)
-        Notes::CreateService.new(
-          sent_notification.project,
-          sent_notification.recipient,
-          note:           reply,
-          noteable_type:  sent_notification.noteable_type,
-          noteable_id:    sent_notification.noteable_id,
-          commit_id:      sent_notification.commit_id,
-          line_code:      sent_notification.line_code
-        ).execute
+        sent_notification.create_note(reply)
       end
     end
   end