Nping: generates incorrect bpf filter expression for IPv6 ICMP

[cpatulea]

$ nping --version
Nping version 0.6.40 ( http://nmap.org/nping )

IPv4:
$ sudo nping --debug -e eth0 --icmp --icmp-type echo 8.8.8.8
...
BPF-filter: (not src host 104.131.51.57 and dst host 104.131.51.57) and ((icmp and icmp[icmptype] = 0) or (icmp and (icmp[icmptype] = 3 or icmp[icmptype] = 4 or icmp[icmptype] = 5 or icmp[icmptype] = 11 or icmp[icmptype] = 12)) )

IPv6:
$ sudo nping --debug -e eth0 -6 --icmp --icmp-type echo 2607:f8b0:400d:c0d::1a
...
BPF-filter: (not src host :: and dst host ::) and ((icmp and icmp[icmptype] = 0) or (icmp and (icmp[icmptype] = 3 or icmp[icmptype] = 4 or icmp[icmptype] = 5 or icmp[icmptype] = 11 or icmp[icmptype] = 12)) )
Opening pcap device eth0
libnsock nsock_pcap_open(): PCAP requested on device 'eth0' with berkeley filter '(not src host :: and dst host ::) and ((icmp and icmp[icmptype] = 0) or (icmp and (icmp[icmptype] = 3 or icmp[icmptype] = 4 or icmp[icmptype] = 5 or icmp[icmptype] = 11 or icmp[icmptype] = 12)) )' (promisc=0 snaplen=8192 to_ms=200) (IOD #1)
Error opening capture device eth0 --> Error compiling our pcap filter: expression rejects all packets

Exactly as reported in:
https://www.reddit.com/r/nmap/comments/3ptky8/is_nping_sending_the_incorrect_icmpv6type_values/

Correct filter tokens for ICMP6 are:
icmp6 - protocol itself
ip6[40] - icmp type
https://hauweele.net/~gawen/blog/?p=1053

[cpatulea]

ICMP filter expression is built here:

nmap/nping/ProbeMode.cc

Line 1465 in ff62300

/* We have an specific ICMP type to look for */

[sibeream]

I have the same problem for TCP.

# ./nping --version
Nping version 0.7.80 ( https://nmap.org/nping )

# ./nping -6 -c1 --tcp --dest-port 9999 --dest-ip ::1 -e lo --debug
...
BPF-filter: (not src host :: and dst host ::) and ((tcp and dst port 45893) or (icmp and (icmp[icmptype] = 3 or icmp[icmptype] = 4 or icmp[icmptype] = 5 or icmp[icmptype] = 11 or icmp[icmptype] = 12)) )

I'll try to fix that.
I guess I should start with the place in code pointed by @cpatulea.
If some of you have information which you think will help to solve this, please share it.