1813513 - Improve serialization of the `font` shorthand

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect)

Description

[Jonathan Kew [:jfkthame]]

Looking at tests for the font shorthand that currently fail in Firefox, I notice there are a whole collection of failures in font-computed.html that happen because when we serialize the shorthand for a computed style, we always include the font-weight value as part of the serialized value even when it is 400, which is redundant.

So, in Firefox we see behavior like:

> document.body.style.font = "12px serif"
< "12px serif"
> window.getComputedStyle(document.body).font
< "400 12px serif" 

IMO, the principle of preferring the shortest serialization means we should omit the 400 here and just return 12px serif. (Note that this is what Chrome does, so although it represents a change from our existing behavior, it seems unlikely to involve major webcompat risk.)

Comment 1

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1813513 - Avoid redundantly serializing the initial value of font-weight (400) as part of the font shorthand in computed style. r=#firefox-style-system-reviewers

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ca83cfa25c03
Avoid redundantly serializing the initial value of font-weight (400) as part of the font shorthand in computed style. r=emilio

Comment 3

[Cristian Tuns]

https://hg.mozilla.org/mozilla-central/rev/ca83cfa25c03