Saved html composed emails not allowed to save further modifications after being printed

Mails composed in html view and saved as draft, do not save further modifications after being printed.

Reported to engineering.

Steps to duplicate:

1. Compose a new email in html format.
2. Add "To" field and "Subject" and have something in the message body.
   
3. Click on "Save Draft" and save the email in "Work In Progress".
4. Make few modifications in the message body or add additional text in the message body and don't save it.
5. Click on File/Print (It's not necessary to actually print, click on cancel).
6. Note that now the save button is greyed out and the modifications are not allowed to save.

Note: Works fine if the email is composed in plain text view.