1593021 - [wpt-sync] Sync PR 20021 - [LayoutNG] Disable first-tier OOF-cache when borders/scrollbars are present.

Status: RESOLVED FIXED

(Core :: Layout: Positioned, task, P4)

Description

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

Sync web-platform-tests PR 20021 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/20021
Details from upstream follow.

Ian Kilpatrick <[e-mail]> wrote:

[LayoutNG] Disable first-tier OOF-cache when borders/scrollbars are present.

The first-tier OOF-cache attempts to skip all the OOF sizing and positioning
work required, as the other cache simply compares the constraint spaces
which can be (relatively) expensive to determine.

This first-tier cache works by comparing the available-size given to the
OOF-positioned descendant. If equal we can skip the OOF-positioned sizing
and positioning steps.

This mostly worked, however had an issue where the containing-block may have
added/removed a borders/scrollbars, but the available-size given remained
the same.

This resulted in an incorrectly positioned OOF-positioned node.

This fix disallows the first-tier cache when borders/scrollbars are present.
This is sufficiently rare that this cache still has a relatively high
hit-rate and is still relative cheap to calculate.

Bug: 1013866
Change-Id: I71d41d2c4b47bcff6412f395db2deabf2f6f3a8f

Reviewed-on: https://chromium-review.googlesource.com/1891768
WPT-Export-Revision: ed8e4d4612d12ae833ffc68fabc89ab04067f64b

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=d9bebd2beacdc1b3853db52948d1e6d421153755

Comment 2

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

GitHub CI Results

wpt.fyi PR Results Base Results

Ran 1 tests

Firefox

PASS: 1

Chrome

FAIL: 1

Safari

PASS: 1

Gecko CI Results

Ran 1 tests
PASS : 1

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8e56b5283f57
[wpt PR 20021] - [LayoutNG] Disable first-tier OOF-cache when borders/scrollbars are present., a=testonly

Comment 4

[Andrei Ciure[:aciure]]

https://hg.mozilla.org/mozilla-central/rev/8e56b5283f57