static void exif_iif_add_fmt(image_info_type *image_info, int section_index,
                             char *name, char *value, ...) {
  va_list arglist;

  va_start(arglist, value);
  if (value) {
    char *tmp = 0;
    php_vspprintf_ap(&tmp, 0, value, arglist);
    exif_iif_add_str(image_info, section_index, name, tmp);
    if (tmp) IM_FREE(tmp);
  }
  va_end(arglist);
}