Closed Bug 1646578 Opened 1 year ago Closed 1 year ago

[wpt-sync] Sync PR 24212 - Don't show scrolling contents layers that are also backface-invisible.

Categories

(Core :: Web Painting, task, P4)

task

Tracking

()

RESOLVED FIXED
mozilla79
Tracking Status
firefox79 --- fixed

People

(Reporter: mozilla.org, Unassigned)

References

()

Details

(Whiteboard: [wptsync downstream])

Sync web-platform-tests PR 24212 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/24212
Details from upstream follow.

Chris Harrelson <chrishtr@chromium.org> wrote:

Don't show scrolling contents layers that are also backface-invisible.

In this situation, we have an element like this:

\<div id=target style="transform: ...; backface-visibility: hidden;
overflow: scroll">
\</div>

It will have two transform and one for scrolling:

Transform
ScrollTranslation

However, overflow clipping is also a grouping property [1], so the
ScrollTranslation will have flattens_inherited_transform true
regardless of the transform-style style of #target.

With TransformInterop on, definitely the scrolling contents should
not be shown (except for pseudo- and stacking context descendants).
This CL changes the behavior for non-TransformInterop also, because
it doesn't seem reasonable to have the behavior the way it is right
now.

[1] https://drafts.csswg.org/css-transforms-2/#grouping-property-values

Bug: 363609

Change-Id: Ib1f356e80644582120e37261d368f774cbcaa6e1
Reviewed-on: https://chromium-review.googlesource.com/2246437
WPT-Export-Revision: c6a9da15e9db754b96b6954f09ef2222ce4c2613

Component: web-platform-tests → Web Painting
Product: Testing → Core

CI Results

Ran 11 Firefox configurations based on mozilla-central, and Firefox, Chrome, and Safari on GitHub CI

Total 1 tests

Status Summary

Firefox

PASS: 1

Chrome

FAIL: 1

Safari

FAIL: 1

Links

Gecko CI (Treeherder)
GitHub PR Head
GitHub PR Base

Pushed by wptsync@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/7446debba5ec
[wpt PR 24212] - Don't show scrolling contents layers that are also backface-invisible., a=testonly
Status: NEW → RESOLVED
Closed: 1 year ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla79
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