Style sheets created from <style> elements have no location, which breaks CSS fetch algorithms

[AtkinsSJ]

What is the issue with the HTML Standard?

This bug comes from interop between the HTML and CSS specs. I'm posting it here as I think the solution is to update the "update a style block" algorithm, but that's just my impression. (I've posted a stub spec issue there for visibility to CSSWG folks: w3c/csswg-drafts#12147)

Style sheets created from <style> elements have no location - see "update a style block"

This breaks multiple CSS fetch algorithms:

• "Fetch an import" step 3 parses the URL using the style sheet's location - this fails for relative imports if there is no location set.
• "Fetch a style resource" step 7 sets the fetch request's referrer to the sheet's location, which is unclear to me but seems to require an actual location.

As far as I can tell, the solution is to modify "update a style block" so that the location of the created style sheet is set to the document's base URL instead of null. I'm not seeing any regressions when doing this in Ladybird, but there might be nuances there I'm missing. Alternatively the CSS algorithms could be adjusted to handle the null-location case.

cc: @noamr as this is related to the other CSS fetch issues.

[AtkinsSJ]

Stumbled across this too:

Style sheets embedded within a document have the base URL associated with their container.

[AtkinsSJ]

Acid3 test 72, requires that <style> style sheets don't have a location, so that probably isn't something that can be changed.