The 'redhat' shutdown mode does not work.

Excerpts from the source code:

static char *halt_command[] = { "/usr/bin/halt", "halt", NULL };
static char *reboot_command[] = { "/usr/bin/reboot", "reboot", NULL };

[...]

  if (command == XFSM_SHUTDOWN_POWEROFF)
    argv = halt_command;
  else
    argv = reboot_command;

[...]

      execv (argv[0], argv);

Hence the halt or reboot command, which should be invoked without a real
parameter, is actually invoked with an extra halt or reboot parameter,
just as if I typed this at the command prompt: /sbin/halt halt

A possible workaround is to modify the execv call to this:

      execv (argv[0], argv+1);