static VP56Frame ref_to_update(VP8Context *s, int update, VP56Frame ref)
{
    VP56RangeCoder *c = &s->c;

    if (update)
        return VP56_FRAME_CURRENT;

    switch (vp8_rac_get_uint(c, 2)) {
    case 1:
        return VP56_FRAME_PREVIOUS;
    case 2:
        return (ref == VP56_FRAME_GOLDEN) ? VP56_FRAME_GOLDEN2 : VP56_FRAME_GOLDEN;
    }
    return VP56_FRAME_NONE;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.