Michael Witten [off-list ref] writes:
It turns out that --compose will also leave some temporary files
behind if git-send-email is terminated out of course.
Should I establish a general handler for SIGTERM and SIGINT?
I was mostly worried about ^C leaving the terminal in a funny
state with your system(stty).
I do not think you should lose the message the user carefully
composed using an editor upon seeing ^C. The user may start to
compose, edit the message, and then at some later time decide to
stop the mail-sending procedure by ^C-ing out. The user would
thank you if you somehow left an escape hatch to allow salvaging
the message, instead of having it to be re-typed from scratch.