lid_customization_option($var_name)) {
    $self->converter_document_error(sprintf(__(
                       "unknown customization variable: %s"),
                                      $var_name));
    if ($self->{'conf'}->{'TEST'}) {
      cluck ("BUG: get_conf: unknown customization variable: $var_name");
    }
    return undef;
  }

  return $self->{'conf'}->{$var_name};
}

sub set_conf($$$)
{
  my $self = shift;
  my $var_name = shift;
  my $value = shift;

  if (!Texinfo::Common::valid_customization_option($var_name)) {
    $self->converter_document_error(sprintf(__(
                       "unknown customization variable: %s"),
                                      $var_name));
    if ($self->{'conf'}->{'TEST'}) {
      cluck ("BUG: set_conf: unknown customization variable: $var_name");
    }
    return 0;
  }

  if ($self->{'configured'}->{$var_name}) {
    return 0;
  } else {
    $self->{'conf'}->{$var_name} = $value;
    return 1;
  }
}

sub force_conf($$$)
{
  my $self = shift;
  my $var_name = shift;
  my $value = shift;

  if (!Texinfo::Common::valid_customization_option($var_name)) {
    $self->converter_document_error(sprintf(__(
                       "unknown customization variable: %s"),
                                      $var_name));
    if ($self->{'conf'}->{'TEST'}) {
      cluck ("BUG: force_conf: unknown customization variable: $var_name");
    }
    return 0;
  }

  $self->{'conf'}->{$var_name} = $value;
  return 1;
}