There is a bug in the assigment modul when files are uploaded an the button "Require students click submit button" is enabled in the settings.
If a student submits a file and clicks the button and a teacher resets this with "Revert back to Draft" and the students submits a second time,
a Mail that he was graded is sent to the student. After submitting the first time, the student gets a mail that he submitted something in the assigment,
which is ok. But when submitting a second time after a teacher reverted the assignment back to draft, the student gets a mail that he was graded,
even if there is no grade or comment.

Steps to reproduce:
1. Create an assignment for file upload where "Require students click submit button" is enabled in the settings
2. Submit a file with a student user in the assigment and click "Submit assignment" button
3. Revert the submission to draft with a teacher
4. Submit a new file and check the E-Mail Notification, it says that the student was graded, but there should be a mail that something was submitted

We are using Moodle 2.3.2+ (Build: 20120920)