net/netip: Need to unmap the Addr in AddrFromSlice due to that there may be an IPv4-mapped IPv6 address

[zhlsunshine]

Generally, the code should not assert an IP address is IPv4 or IPv6 via the slice length due to there may be an IPv4-mapped IPv6 address, so need to unmap the Addr in AddrFromSlice in net/netip package.

This can be reproduced by calling net.DefaultResolver.LookupNetIP in net package to obtain all interfaces and then each interface address may be in an IPv4-mapped IPv6 address, and this will cause the problem when checking an address's IP family.

[gopherbot]

This PR (HEAD: 6186106) has been imported to Gerrit for code review.

Please visit https://go-review.googlesource.com/c/go/+/445275 to see it.

Tip: You can toggle comments from me using the comments slash command (e.g. /comments off)
See the Wiki page for more info

[gopherbot]

Message from Zeke Lu:

Patch Set 2:

(1 comment)

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/445275.
After addressing review feedback, remember to publish your drafts!

[gopherbot]

This PR (HEAD: e86a494) has been imported to Gerrit for code review.

Please visit https://go-review.googlesource.com/c/go/+/445275 to see it.

Tip: You can toggle comments from me using the comments slash command (e.g. /comments off)
See the Wiki page for more info

[gopherbot]

Message from Huailong Zhang:

Patch Set 2:

(2 comments)

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/445275.
After addressing review feedback, remember to publish your drafts!

[gopherbot]

Message from Zeke Lu:

Patch Set 3:

(1 comment)

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/445275.
After addressing review feedback, remember to publish your drafts!

[gopherbot]

Message from Damien Neil:

Patch Set 3:

(2 comments)

---

Please don’t reply on this GitHub thread. Visit golang.org/cl/445275.
After addressing review feedback, remember to publish your drafts!

[ZekeLu]

Hi @zhlsunshine, now that https://go.dev/cl/415580 is merged and net.DefaultResolver.LookupNetIP won't return IPv4-mapped IPv6 address. Can you verify whether it addresses your issue? Thanks!