Multi-site subdomain sub-site home and siteurl scheme breaks FSE themes custom fonts

[RavanH]

On a Multi-site in subdomaine mode, where the main site home and siterurl are both on https, newly created sub-sites will have http instead of https. Looking at [install_blog()](https://core.trac.wordpress.org/browser/tags/4.9.4/src/wp-includes/ms-functions.php#L1434) This appears to be by design. Only when ! is_subdomain_install() and the main site is on https, the home ans siteurl are forced to https.

I see the logic in this. Not everyone might have a wildcard SSL ready.

But it does create a problem:

If there is a wildcard SSL license, and http>https redirects, HTST or browser preferences in place, subsites will be accessed over https.

When such a sub-site uses (for example) the Twenty Twenty-Five theme and the site admin has set a custom font downloaded via the Google Fonts dialog in the Site Editor, the resource will be referenced over http in the front end page source.

These are blocked by the browser as insecure requests and the font will not be rendered on the site.

Only manually setting each home and siteurl for each subsite via the Network > Sites admin (or directly in the DB) solves the issue.

An annoying little issue that might be solved by a network option like "Site uses HTTPS" under Network > Settings > New Site Settings.

[RavanH]

Sorry, I realized too late that I referenced a now deprecated function install_blog()... But the issue remains the same.

Found a *very* old thread https://core.trac.wordpress.org/ticket/27499 discussing this topic but was closed with a wontfix :/

However, I do feel the topic has become more relevant through this apparent conflict with the Site Editor custom fonts feature.

[RavanH]

And a newer related ticket #60957

[realloc]

Closing as a duplicate of #27499, which covers the root cause: new subdomain sites are created with the http scheme even when the network runs on https. The FSE custom-font breakage reported here is a useful real-world symptom, so I've added it to #27499. See also #60957 for the same Font Library issue.

[sabernhardt]

Duplicate of #27499.