1851227 - [wpt-sync] Sync PR 41766 - Make standards-track pseudo-elements override style attributes in UA shadow DOM.

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, task, P4)

Description

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Sync web-platform-tests PR 41766 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/41766
Details from upstream follow.

L. David Baron <[e-mail]> wrote:

Make standards-track pseudo-elements override style attributes in UA shadow DOM.

This makes pseudo-elements representing elements in user-agent shadow
DOM (via Element::ShadowPseudoId()) whose names do not begin with
-webkit- or -internal- override style attributes in the user-agent
shadow DOM. This matches developer expectations and makes sense given
https://drafts.csswg.org/css-cascade-5/#cascade-context since the
pseudo-elements are in an outer context.

The only such pseudo-elements that exist today are the experimental
::details-content and ::details-summary pseudo-elements. (See the
DCHECK() in Element::SetShadowPseudoId().)

TODO(https://crbug.com/1478230): Devtools does not currently show the
correct cascading order since it assumes that style attributes always
win. We should fix this before shipping this code.

Bug: 1469418
Change-Id: I246e6436fd1f68622f73afe2f8c709ed35ad6cd2
Reviewed-on: https://chromium-review.googlesource.com/4823787
WPT-Export-Revision: 2c4b501404ae6b93bb188e785ecaf98c98b27707

Comment 1

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Pushed to try (stability) https://treeherder.mozilla.org/#/jobs?repo=try&revision=20ab3e459d15795a0d21a42e2fbcf129a1757fc4

Comment 2

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

CI Results

Ran 0 Firefox configurations based on mozilla-central, and Firefox, Chrome, and Safari on GitHub CI

Total 1 tests

Status Summary

Firefox

FAIL: 1

Chrome

FAIL: 1

Safari

FAIL: 1

Links

GitHub PR Head
GitHub PR Base

Details

New Tests That Don't Pass

• /html/rendering/the-details-element/details-pseudo-elements-002.tentative.html [wpt.fyi]: FAIL (Chrome: FAIL, Safari: FAIL)

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f2b3253fc7d0
[wpt PR 41766] - Make standards-track pseudo-elements override style attributes in UA shadow DOM., a=testonly
https://hg.mozilla.org/integration/autoland/rev/bd533c1315f4
[wpt PR 41766] - Update wpt metadata, a=testonly

Comment 4

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/f2b3253fc7d0
https://hg.mozilla.org/mozilla-central/rev/bd533c1315f4