t.Logf("sigwinch...")
	syscall.Kill(syscall.Getpid(), syscall.SIGWINCH)
	waitSigAll(t, c1, syscall.SIGWINCH)

	// Send two more SIGHUPs, to make sure that
	// they get delivered on c1 and that not reading
	// from c does not block everything.
	t.Logf("sighup...")
	syscall.Kill(syscall.Getpid(), syscall.SIGHUP)
	waitSigAll(t, c1, syscall.SIGHUP)
	t.Logf("sighup...")
	syscall.Kill(syscall.Getpid(), syscall.SIGHUP)