distfile downloads failing on https

[Jan Stary]

Recently, I have tweaked textproc/lowdown
https://github.com/macports/macports-ports/pull/1245
to download the distfile from a http master site, not a https one,
because the https server rejects the weak ssl of some older MacOS systems,
which could not download the distfile then.

That worked for a while, but now the server (kristaps.bsd.lv)
redirects any http request to https anyway, so the downloads fail again.
I understand this is a general problem, not specific to the lowdown port.

One workaround would be to have a copies of the distfiles in
http://distfiles.macports.org/, but it seems the distfile mirroring
has been broken for more than a year:
https://trac.macports.org/ticket/53347

A more general proposed solution was to bunlde a newer curl with MP,
in partcular one built against a newer SSL/TLS library:
https://trac.macports.org/ticket/51516

Is there any progress in any of these?

To be sure: when downloading a distfile, does MP always use the system's
native curl(1)? Or does it try the port's curl(1), if installed?
Or does it try the port's curl(1) _first_?

On this old system where I'm experiencing the problem, these are:

$ /usr/bin/curl --version
curl 7.19.7 (universal-apple-darwin10.0) libcurl/7.19.7 OpenSSL/0.9.8y
zlib/1.2.3
Protocols: tftp ftp telnet dict ldap http file https ftps 
Features: GSS-Negotiate IPv6 Largefile NTLM SSL libz 

$ /opt/local/bin/curl --version
curl 7.54.1 (x86_64-apple-darwin10.8.0) libcurl/7.54.1 OpenSSL/1.0.2n
zlib/1.2.11
Release-Date: 2017-06-14
Protocols: dict file ftp ftps gopher http https imap imaps pop3 pop3s
rtsp smb smbs smtp smtps telnet tftp 
Features: IPv6 Largefile NTLM NTLM_WB SSL libz TLS-SRP UnixSockets HTTPS-proxy 

	Jan