1908279 - @scope :scope::part() doesn't work

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect)

Description

[709922234]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:130.0) Gecko/20100101 Firefox/130.0

Steps to reproduce:

https://codepen.io/mantou132/pen/rNEOXKV

Actual results:

"Blue" not blue

Expected results:

"Blue" is blue

Comment 1

[709922234]

Strangely, in another example, :scope::part seems to work, but it fails with multiple scopes:

• visit https://examples.gemjs.org
• navigator to "Console" from side bar
• navigator to "Client Pagination" from new page side bar
• click table header "No" cell

The first :scope::part() style seems to be applied to other elements, bug https://codepen.io/mantou132/pen/pomaOjB work.

Comment 2

[709922234]

Attachment: 20240717-104211.jpg

Comment 3

[Mayank Bansal]

Attachment: reporters standalone testcase.html

Comment 4

[Mayank Bansal]

Can confirm that Nightly does not show colors, and Chrome does.
ni? from :dshin.

Comment 5

[Daniel Holbert [:dholbert]]

Missing-but-implied bit of STR: set about:config layout.css.at-scope.enabled to true to enable this feature. (That pref defaults to false for now -- reference: https://searchfox.org/mozilla-central/rev/8c6edfe25c094e032a27722ef30f69555f556bf8/modules/libpref/init/StaticPrefList.yaml#9095-9098 )

With that, Nightly renders the linked codepen with the word "Red" written in red, but the word "Blue" is written in a black (default) color, as described in comment 0.

Comment 6

[David Shin[:dshin]]

Attachment: Bug 1908279: Let the @scope root search cross the shadow boundary if ::part selector is used. r=#style

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/13085ea1774d
Let the @scope root search cross the shadow boundary if ::part selector is used. r=firefox-style-system-reviewers,emilio

Comment 8

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

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/47487 for changes under testing/web-platform/tests

Comment 9

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/13085ea1774d

Comment 10

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

Upstream PR merged by moz-wptsync-bot