Bug 215359

Summary:

@font-face font-weight descriptor should reject bolder and lighter

Product:

WebKit

Reporter:

Takeshi Kurosawa <taken.spc>

Component:

CSS

Assignee:

Nobody <webkit-unassigned>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

darin, esprehn+autocc, ews-watchlist, glenn, gyuyoung.kim, macpherson, menard, mmaxfield, webkit-bug-importer

Priority:

Keywords:

InRadar

Version:

WebKit Nightly Build

Hardware:

Unspecified

OS:

Unspecified

Attachments:

Description	Flags
Patch	none

Description Takeshi Kurosawa 2020-08-10 23:12:58 PDT

Both "bolder" and "lighter" are not allowed for @font-face font-weight descriptor.

https://www.w3.org/TR/css-fonts-3/#descdef-font-weight
> Name: 	font-weight
> Value: 	normal | bold | 100 | 200 | 300 | 400 | 500 | 600 | 700 | 800 | 900 

https://drafts.csswg.org/css-fonts-4/#descdef-font-face-font-weight
> For: 	@font-face
> Value: 	auto | <font-weight-absolute> <font-weight-absolute>?

In WebKit, CSS parser accepts "bolder" and "lighter" and font resolver computes absolute weight from "bolder" and "lighter". This doesn't match other browsers behavior and the specs. Rejecting "bolder" and "lighter" improves interoperability and spec compliance.

WPT.fyi
https://wpt.fyi/results/css/css-fonts/variations/at-font-face-descriptors.html

Firefox's CSS parser rejects "bolder" and "lighter".
https://bugzilla.mozilla.org/show_bug.cgi?id=1454596


Chrome's CSS parser accepts "bolder" and "lighter" and its font resolver doesn't use "bolder" and "lighter" (I think it's confusing).
https://source.chromium.org/chromium/chromium/src/+/master:third_party/blink/renderer/core/css/font_face.cc;l=661-678;drc=b80faef62a12ac2966f19b014e845a8137718885

Comment 1 Takeshi Kurosawa 2020-08-10 23:28:02 PDT

Created attachment 406367 [details]
Patch

Comment 2 Takeshi Kurosawa 2020-08-14 08:59:40 PDT

Comment on attachment 406367 [details]
Patch

Thank you for reviewing! Could someone land this please?

Comment 3 EWS 2020-08-14 10:34:45 PDT

Committed r265677: <https://trac.webkit.org/changeset/265677>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 406367 [details].

Comment 4 Radar WebKit Bug Importer 2020-08-14 10:35:18 PDT

<rdar://problem/67081913>