I'm trying to debug why tmux processes still think they're attached when I close the terminal they live inside of, and I think I've discovered part of the problem; when I close a terminal window (CMD-W or clicking the little red button in the top left) it doesn't send SIGHUP! In fact, it only sends SIGEXIT. I discovered this using the script from this SO question. One of the posters gave a very different result from his OSX machine, however my terminal does not seem to want to play nicely.
Does anyone know how to make the terminal in OSX (I'm running 10.7.2) send the proper signals when exiting? Thanks!