snprintf (fullpath, sizeof (fullpath), "%s/%s", folder, path);
mutt_concat_path (fullpath, folder, path, sizeof (fullpath));
static int link_is_dir (const char *folder, const char *path){  struct stat st;  char fullpath[_POSIX_PATH_MAX];    snprintf (fullpath, sizeof (fullpath), "%s/%s", folder, path);    if (stat (fullpath, &st) == 0)    return (S_ISDIR (st.st_mode));  else    return 0;}