buffer overflows in the tty flip buffer in 2.6.17

["Mockern" <Mockern@yandex.ru>]

When data is received from the hardware, it needs to be placed into the tty device's flip buffer. This can be done with the following bit of code:

for (i = 0; i < data_size; ++i) {
        if (tty->flip.count >= TTY_FLIPBUF_SIZE)
                tty_flip_buffer_push(tty);
        tty_insert_flip_char(tty, data[i], 0);
}
tty_flip_buffer_push(tty);

This example makes sure there are no buffer overflows in the tty flip buffer as the data is being added. 

But how it is done in 2.6.17 linux kernel? I did check this "overflow code" in new tty driver's code. This code looks like just removed. But somehow overflow in the tty buffer must be kept.