unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag,
                           const char* transkey, const char* str)
{
  char** new_keys = (char**)(realloc(info->itext_keys, sizeof(char*) * (info->itext_num + 1)));
  char** new_langtags = (char**)(realloc(info->itext_langtags, sizeof(char*) * (info->itext_num + 1)));
  char** new_transkeys = (char**)(realloc(info->itext_transkeys, sizeof(char*) * (info->itext_num + 1)));
  char** new_strings = (char**)(realloc(info->itext_strings, sizeof(char*) * (info->itext_num + 1)));
  if(!new_keys || !new_langtags || !new_transkeys || !new_strings)
  {
    free(new_keys);
    free(new_langtags);
    free(new_transkeys);
    free(new_strings);
    return 83; /*alloc fail*/
  }

  info->itext_num++;
  info->itext_keys = new_keys;
  info->itext_langtags = new_langtags;
  info->itext_transkeys = new_transkeys;
  info->itext_strings = new_strings;

  string_init(&info->itext_keys[info->itext_num - 1]);
  string_set(&info->itext_keys[info->itext_num - 1], key);

  string_init(&info->itext_langtags[info->itext_num - 1]);
  string_set(&info->itext_langtags[info->itext_num - 1], langtag);

  string_init(&info->itext_transkeys[info->itext_num - 1]);
  string_set(&info->itext_transkeys[info->itext_num - 1], transkey);

  string_init(&info->itext_strings[info->itext_num - 1]);
  string_set(&info->itext_strings[info->itext_num - 1], str);

  return 0;
}
Unknown