site.github.url metadata provides http url creating a mixed content error when used on github.io pages

[seamustuohy]

Before submitting an issue, please be sure to

• Read the contributing instructions
• Update to the latest Gem version (either gem update pages-gem or bundle update pages-gem)
  Not a build "error" but a configuration request.

This issue affects

• The site generated by GitHub Pages
• Building sites locally

What did you do (e.g., steps to reproduce)

• Create a github.io page
• install HTTPS everywhere or configure browser to reject mixed content
• Add local static CSS file to github page prepended with site.github.url

<link rel="stylesheet" href="{{ "/css/main.css" | prepend: site.github.url }}">

• open chrome developers tab and go to network section
• load website in browser
• encounter mixed content error that stops css from loading.

What did you expect to happen?

I expected the site url protocol to match the protocol provided by github pages.

What happened instead?

The url I was provided was HTTP while the github page was delivered using HTTPS

Additional information

• Link to the live site (if applicable):
• Link to the source repo (if applicable):

I plan to create a fix for this in the next few minutes. But it can be recreated using the following commit in my repository. (It is easy enough to reproduce without, but I thought I'd make it available.)

https://github.com/OpenInternet/copilot/tree/219d9508737b1a0b0edd14380fece63cb3d8c60d

[parkr]

HTTPS is not officially supported. Once it is, jekyll-github-metadata will be updated with this to ensure HTTPS is used everywhere. Thanks for your understanding!

[gauntface]

I just got by this as well, one solution is to remove the specific HTTP protocol and use what ever the page is served over:

{{ "/css/main.css" | prepend: site.github.url | replace: 'http://', '//' }}

[petrgazarov]

If you are using Cloudflare, you can take advantage of Automatic HTTPS Rewrites

[mattn]

GitHub enable HTTPS on GitHub Pages.

https://blog.github.com/2018-05-01-github-pages-custom-domains-https/

So site.url always be wrong. Most of GitHub users will add workaround {{ site.url | replace: 'http://', '//'}}. How about to add new attribute like site.url_noscheme or something?