[bug#33801] import: github: Support source URIs that redirect to GitHub

[Ludovic Courtès]

Hi,

Arun Isaac <address@hidden> skribis:

> Many GitHub hosted packages (for example, youtube-dl) present source
> tarballs for download on their website
> (https://yt-dl.org/downloads/latest/youtube-dl-2018.12.17.tar.gz). But
> these URIs just redirect to GitHub. Currently, our GitHub refresher
> does not cover these packages. This patch addresses that.

Good idea!  Do you know how many packages fall into that category?

> From 90f756fd6f7df50236023e120cb040f6e5d1718c Mon Sep 17 00:00:00 2001
> From: Arun Isaac <address@hidden>
> Date: Wed, 19 Dec 2018 15:59:52 +0530
> Subject: [PATCH] import: github: Support source URIs that redirect to GitHub.
>
> * guix/import/github.scm (follow-redirects-to-github): New function.
> (updated-github-url)[updated-url]: For source URIs on other domains, replace
> all instances of the old version with the new version.
> (latest-release)[origin-github-uri]: If necessary, follow redirects to find
> the GitHub URI.

[...]

> +(define (follow-redirects-to-github uri)
> +  "Follow redirects of URI until a GitHub URI is found. Return that GitHub
> +URI. If no GitHub URI is found, return #f."

Perhaps add the yt-dl.org example as a comment here.

> +  (define (follow-redirect uri)
> +    (receive (response body) (http-get uri #:streaming? #t)

Add: (close-port body).

Otherwise LGTM, thanks!

Ludo’.