use strict;             # leak occurs whether strict is used or not

while(1) {
  &leak();
}

sub leak {
  my $sub_ref;
  $sub_ref = sub { &$sub_ref(); };
  return 0;
}

##</code><code>##

sub leak {
  my $factorial_sub_ref;

  $factorial_sub_ref = sub {
    my ($number) = @_;
    if ($number < 2) { return 1; }
    return($number + &$factorial_sub_ref($number - 1));
  };

  return 0;
}