The logout function works abnormal after logout with unsaved gedit file

[Eason]

The logout function works abnormal after logout with unsaved gedit file. No prompt about "Save the changes" or “Force logout". The icons in desktop will disappear, and after sevral minutes, system logout success.

用Gedit打开文本文档并作出修改，注销系统，注销功能异常。没有强制注销或者提示保存的选项，桌面图标消失，过了几分钟后，才会注销成功。

Steps:
1. Open any file with gedit
2. Change the file and don't save the changes
3. Logout the system
-->Failed. The logout function works abnormal.

Configuration:
OS: Ubuntu kylin 15.04