1793072 - [wpt-sync] Sync PR 36129 - Store actual fragmentainer offset in constraint space.

Status: RESOLVED FIXED

(Core :: Layout, task, P4)

Description

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

Sync web-platform-tests PR 36129 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/36129
Details from upstream follow.

Morten Stenshorne <[e-mail]> wrote:

Store actual fragmentainer offset in constraint space.

The constraint space used to store the block-offset of the nearest block
formatting context root (within the fragmentainer), rather than the
actual block-offset of the element being laid out. Since this offset was
part of the cache key, it could cause false cache hits, as the test
included demonstrates. The actual block-offset of a fragment may change,
even if the block formatting context stays where it was.

Storing the block-offset within the fragmentainer on the constraint
space means that we need to always [*] go back and relayout if the BFC
block-offset resolution results in anything different from the estimated
offset.

[*] Only when block fragmentation is involved, though.

This issue was discovered while working on caching fragmented nodes (an
upcoming CL).

Change-Id: Ica69133189a042b6b066453cc6920e5b1e07c35c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3923597
Reviewed-by: Ian Kilpatrick \<[e-mail]>
Commit-Queue: Morten Stenshorne \<[e-mail]>
Cr-Commit-Position: refs/heads/main@{#1053256}

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=297ae25a5b10a83339b926d317d8710ee38fdf74

Comment 2

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

CI Results

Ran 9 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

PASS: 1

Links

Gecko CI (Treeherder)
GitHub PR Head
GitHub PR Base

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/7f01da10a11e
[wpt PR 36129] - Store actual fragmentainer offset in constraint space., a=testonly

Comment 4

[Iulian Moraru]

https://hg.mozilla.org/mozilla-central/rev/7f01da10a11e