Add option which prompts the user whether they want to discard a comment which was not sent

I have typed a longer comment before and then accidentally pressed the "back" button on my smartphone before I posted it. The comment was sadly lost and the time I invested was wasted.

I haven't seen an option, which I could enable, such that Jerboa would show me a prompt whether I really want to go back, if I haven't posted the comment yet.

Did I miss it? If not, feel invited to see this as a feature request. (: