static UINT32 safe_buffer_copy(const void *source, UINT32 sourceoffs, UINT32 sourcelen, void *dest, UINT32 destoffs, UINT32 destlen)
{
    int sourceavail = sourcelen - sourceoffs;
    int destavail = destlen - destoffs;
    int bytes_to_copy = sourceavail < destavail ? sourceavail : destavail;
    if (bytes_to_copy > 0)
        memcpy((UINT8 *)dest + destoffs, (const UINT8 *)source + sourceoffs, bytes_to_copy);
    return bytes_to_copy > 0 ? bytes_to_copy : 0;
}