The same example, but the child creates becomes the leader of a new process group.

What happens now, when a SIGINT interrupts the terminal?

  ...
  signal(SIGINT, handlerP);
  shell_pid = getppid();
  mypid = fork();
  if ( mypid == 0 ) {
    signal(SIGINT, handlerC);
    setpgid(0, getpid());
    ...