[csswg-drafts] [css-fonts] Clarify: use of referrers in font fetching and relationship with preloads (#6775)

noamr has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-fonts] Clarify: use of referrers in font fetching and relationship with preloads  ==
Currently it is not specified how fonts are fetched. [This PR](https://github.com/w3c/csswg-drafts/pull/6715) attempts to fix that.

However, currently there is a behavior mismatch around referrers and fonts.
When fetching web-fonts, Gecko & Chromium send the URL of the stylesheet where the font is defined rather than the URL of the document as the referrer for the font (Safari loads web-fonts without CORS).

It's unclear what this was meant for, but it has the effect of not being fully compatible with preloading (`<link rel="preload">`). Because a preload doesn't have a way to specify a referrer, and the embedding HTML does not always know which stylesheet URL will eventually load the font, this may result in incompatibilities between the preloaded request and the actual request.

I suggest to not send the stylesheet URL as a referrer to avoid this problem, but I'm not sure of the implications.

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/6775 using your GitHub account


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Received on Thursday, 28 October 2021 12:33:52 UTC