misc/57039: nycdn.netbsd.org redirects to URL without hostname

[louis%zabrico.com@localhost]

>Number:         57039
>Category:       misc
>Synopsis:       nycdn.netbsd.org redirects to URI without hostname
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    misc-bug-people
>State:          open
>Class:          support
>Submitter-Id:   net
>Arrival-Date:   Fri Sep 30 16:15:00 +0000 2022
>Originator:     Louis Guillaume
>Release:        NetBSD 9.3_STABLE
>Organization:
>Environment:
System: NetBSD ptah.zabrico.com 9.3_STABLE NetBSD 9.3_STABLE (XEN3_DOMU) #0: Wed Aug 17 16:43:50 UTC 2022 mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/xen/compile/XEN3_DOMU amd64
Architecture: x86_64
Machine: amd64
>Description:
	While attempting to automate retrieval of nightly binaries from nycdn.netbsd.org,
        I noticed that my script, which uses "tnftp", fails to retrieve the nightly
	kernels because the web server redirects (302) to a URL that does not include the
	protocol, host or port. Only the path URI is included.
	I'm not sure what is normally expected of the HTTP client but tnftp does not
	reassemble the URL with the original host:port when it's missing in the redirect
	path. Maybe this is actually a tnftp or libfetch bug??
>How-To-Repeat:
	Attempt to retrieve a kernel using "ftp" on a netbsd machine. e.g.:
	# ftp -a http://nycdn.netbsd.org/pub/NetBSD-daily/netbsd-9/latest/amd64/binary/kernel/netbsd-INSTALL_XEN3_DOMU.gz
	Trying [2a04:4e42:31::262]:80 ...
	ftp: Can't connect to `2a04:4e42:31::262:80': No route to host
	Trying 151.101.209.6:80 ...
	Requesting http://nycdn.netbsd.org/pub/NetBSD-daily/netbsd-9/latest/amd64/binary/kernel/netbsd-INSTALL_XEN3_DOMU.gz
	Redirected to /pub/NetBSD-daily/netbsd-9/202209281530Z/amd64/binary/kernel/netbsd-INSTALL_XEN3_DOMU.gz
	ftp: Can't lookup `/pub/NetBSD-daily/netbsd-9/202209281530Z/amd64/binary/kernel/netbsd-INSTALL_XEN3_DOMU.gz:ftp': Non-recoverable failure in name resolution
	ftp: Can't connect or login to host `/pub/NetBSD-daily/netbsd-9/202209281530Z/amd64/binary/kernel/netbsd-INSTALL_XEN3_DOMU.gz:?'
>Fix: