If your quiz is set up with option "When time expires" set to "Open attempts are submitted automatically" and the user is answering a question in full screen mode of tinyMCE-Editor the answer will not be saved when time is running up!

Steps to reproduce the bug:

1. Create a quiz with a question of question type "essay" and a scheduled time frame and the option "When time expires" set to "Open attempts are submitted automatically".
2. Enter the course as a student and make sure the tinyMCE editor is the student's editor of choice.
3. Start attempting the quiz during the time frame, go to the essay question and edit the answer in full screen mode of the editor (don't leave the full screen mode).
4. Wait for the time running up.
5. You will see that the answer was not saved.

Tested with boost and clean theme in Chrome and Firefox on Mac.