absolute_url should complain if URL is not absolute

[pathawks]

If site.url == example.org, then {{ "/" | absolute_url }} will return example.org/.

If the current page (https://example.org/about/) includes a link to the above URL, visiting that link will direct the browser to https://example.org/about/example.org/.

This is obviously not the intended behavior.

Now that jekyll-sitemap and jekyll-feed are relying on these filters, a site.url that does not contain a protocol can bork a site's entire sitemap or feed.

I don't know if this is best fixed with jekyll doctor or by complaining at build time.

[parkr]

Duplicate of #5788?

[pathawks]

Duplicate of #5788?

No. Kind of the opposite.

In this case, if site.url is not absolute, then the absolute_url filter will never work: it will never generate an absolute URL.

Edit: But I guess it is the problem I am trying to fix in #5760

[ashmaroli]

@pathawks the PR linked to this ticket has been merged. Is this still an issue?

[pathawks]

@ashmaroli Good catch 👍