tcpopt_len_check will stop the stack when option length is 0

[chenzch]

In pico_tcp.c tcp_parse_option_* functions call tcpopt_len_check. If the len ( the length of option ) is 0, tcpopt_len_check makes the index ( i ) roll back. The loop in tcp_parse_options will not jump out.

[maximevince]

Hi @chenzch ,

I invite you to move to the maintained fork of picoTCP at https://gitlab.com/insane-adding-machines/picotcp/
Please re-file the bug there, if it's still applicable.

Thanks!