Open Bug 1371943 Opened 7 years ago Updated 2 years ago

Update transform-box initial & fallback values to match latest CSS WG resolution

Categories

(Core :: Layout, defect, P3)

53 Branch
defect

Tracking

()

People

(Reporter: amelia.bellamy.royds, Unassigned)

References

(Blocks 1 open bug)

Details

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36 Steps to reproduce: In Firefox 55, the transform-box property is implemented according to the spec as it existed a couple months ago. Implementation shipped as described in issue #1208550 Actual results: In the process of getting other browsers support, some issues with the current spec were identified. The CSS WG resolved to change the initial value of the property and the way that the CSS box layout values map to SVG layout values (and vice versa). See summary here: https://github.com/w3c/csswg-drafts/issues/857#issuecomment-296074806 Blink and WebKit are working on implementations based on the latest resolutions: - Chromium bug: https://bugs.chromium.org/p/chromium/issues/detail?id=595829 - WebKit bug: https://bugs.webkit.org/show_bug.cgi?id=145783 Expected results: The following changes affect the Firefox implementation: - The initial value is now `view-box` - The used values change when a CSS box keyword is used for an element without CSS layout boxes, or when an SVG box keyword is used for an element without SVG layout. The correspondences are those defined in the draft Fill & Stroke module for the fill-origin property: https://drafts.fxtf.org/fill-stroke-3/#fill-origin
Blocks: 1208550
Status: UNCONFIRMED → NEW
Ever confirmed: true
Priority: -- → P3
Assignee: nobody → cku
Assignee: cku → nobody

For reference / searchability: the specific CSSWG resolutions here were:

RESOLVED: Add "auto" as initial value for transform-box, give it the current border-box/view-box dual behavior
RESOLVED: Add stroke/padding/content-box, and set up the proper mappings between them for transform-box.

It looks like padding-box didn't end up making it into the spec (perhaps due to another spec change or resolution), but stroke-box and content-box did:
https://drafts.csswg.org/css-transforms/#transform-box

And Firefox's lack-of-support for those values is what's causing these WPT tests to fail:
https://wpt.fyi/results/css/css-transforms/parsing/transform-box-valid.html
https://wpt.fyi/results/css/css-transforms/parsing/transform-box-computed.html

To a first approximation, this bug is probably responsible for all the failures here as well:
https://wpt.fyi/results/css/css-transforms/transform-box?label=master&label=experimental&aligned&q=firefox%3Afail

Blocks: compat2021
Severity: normal → S3
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