add: buf[sizeof(buf)-1] = '\0';
context: Ns_DStringPrintf(Ns_DString *dsPtr, char *fmt,...){    char            buf[NS_DSTRING_PRINTF_MAX+1];    va_list         ap;    va_start(ap, fmt);#if NO_VSNPRINTF    /* NB: Technically unsafe. */    vsprintf(buf, fmt, ap);#else    vsnprintf(buf, sizeof(buf)-1, fmt, ap);#endif    va_end(ap);    return Ns_DStringAppend(dsPtr, buf);}