net/http: Client.Do blocks on DNS AAAA record until timeout even after A record succeeds [1.22 backport]

[gopherbot]

@kkHAIKE requested issue #57697 to be considered for backport to the next 1.22 minor release.

@gopherbot please consider this for backport to 1.22

[gopherbot]

Change https://go.dev/cl/565296 mentions this issue: [release-branch.go1.22] net: prevent unintended retries upon receiving an empty answer response from the DNS server.

[mknyszek]

We're leaning toward denying this issue for backport because it's an old bug (since at least Go 1.18) and the risk of introducing a new bug in an old release is too high.

Do you have any additional justification for backporting this issue? Also, backports (per our policy) always need to apply to both supported Go releases (so in this case Go 1.21 and Go 1.22) if it applies to both.

[kkHAIKE]

Actually, I also want to backport to 1.21, but this CL depends on https://go-review.googlesource.com/c/go/+/514835, and it's not a bug fix CL, so I'm quite troubled.

[thanm]

Discussed in the go release team weekly checkin. Given no new information we've decided to reject this backport request, thanks.