[csswg-drafts] [cssom] Serialization of `@font-face` assumes `font-family` descriptor is always present (#13323)

Calme1709 has just created a new issue for https://github.com/w3c/csswg-drafts:

== [cssom] Serialization of `@font-face` assumes `font-family` descriptor is always present ==
The [`@font-face` section of the CSS fonts spec](https://drafts.csswg.org/css-fonts-4/#font-face-rule) states that
>@​font-face rules require a font-family and src descriptor; if either of these are missing, the @​font-face rule must not be considered when performing the font matching algorithm.

This implies that `@font-face` rules without valid `font-family` descriptors are valid through parse time and just don't take part in font matching, this behavior is exhibited by both Chrome and Firefox.

The issue arises when [serializing the associated `CSSFontFaceRule`](https://drafts.csswg.org/cssom/#ref-for-cssfontfacerule) where step 3 assumes that the `font-family` descriptor is always present.

This issue is avoided in Chrome and Firefox by skipping steps 2-4 of the serialization algorithm if the `font-family` descriptor is not present.

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/13323 using your GitHub account


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Received on Saturday, 10 January 2026 04:27:41 UTC