install/57991: sysinst http/ftp download Host isn't clear about IPv6 address syntax

[campbell+netbsd%mumble.net@localhost]

>Number:         57991
>Category:       install
>Synopsis:       sysinst http/ftp download Host isn't clear about IPv6 address syntax
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    install-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Mar 03 04:00:00 +0000 2024
>Originator:     Taylor R Campbell
>Release:        current (10.99.4)
>Organization:
The Sysinstall6 Foundation
>Environment:
>Description:
When I ask to download sets via HTTP or FTP, the Host field seems an appropriate place to put an IPv6 address, but it can't be put in verbatim because sysinst passes it through to ftp(1) without escaping:

     Status: Command failed
    Command: /usr/bin/ftp -a http://2001:db8::1234/evbarm-aarch64/binary/sets/modules.tgz
     Hit enter to continue
────────────────────────────────────────────────────────────────────────────────
ftp: Unknown port `db8::1234' in URL `http://2001:db8::1234/evbarm-aarch64/binary/sets/modules.tgz'

>How-To-Repeat:
type an IPv6 address into the Host field for downloading sets
>Fix:
sysinst needs to recognize the IPv6 address and wrap it in square brackets:

/usr/bin/ftp -a http://[2001:db8::1234]/evbarm-aarch64/binary/sets/modules.tgz