[PATCH stable] chg: forward SIGWINCH to worker

[Yuya Nishihara]

On Sun, 17 Apr 2016 00:29:35 +0100, Jun Wu wrote:
> I notice that setupsignalhandler() can be cleaned up a bit (remove
> duplicated "sa.sa_flags = SA_RESTART;", "sa.sa_handler = forwardsignal;"
> and add a comment for SIGHUP, SIGINT, besides, explain why handlestopsignal
> is used instead of just forwardsignal).

Well, I made it verbose by intention so that I can easily see which signal is
handled by which function. I'd rather reorganize the first SIGHUP/SIGINT/SIGTERM
block, and add comment for it.