1672891 - [wpt-sync] Sync PR 26247 - Propagate previous fragment's break token for OOF fragmentation layout

Status: RESOLVED FIXED

(Core :: Layout, task, P4)

Description

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

Sync web-platform-tests PR 26247 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/26247
Details from upstream follow.

b'Daniel Libby <[e-mail]>' wrote:

Propagate previous fragment's break token for OOF fragmentation layout

When adding out-of-flow results to a fragmentainer, we currently are not
setting up the break token sequence number on the NGBoxFragmentBuilder
for the NGSimplifiedOOFLayoutAlgorithm. This results in painting
different fragments with the same fragmentainer identifier in
NGBoxFragmentPainter::PaintBlockChildren, which causes a DCHECK in
display item caching code.

Instead, use the previous fragment's BreakToken when creating the
NGSimplifiedOOFLayoutAlgorithm. This gets the sequence numbers correct,
whether we replace or create new fragments (for the former
we could just use the existing break token/sequence number).

This adds a WPT test for the unit test that exposed this issue:
NGOutOfFlowLayoutPartTest::PositionedFragmentationWithOverflow

Bug: 1134763

Change-Id: I48a230f8153b8ea63c3a376629c645656423fc2b
Reviewed-on: https://chromium-review.googlesource.com/2490209
WPT-Export-Revision: d01f6d4b73644b5431d28c52df16168520d6ecd0

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=296bf2ce5d94ca58ef250880a272eab21969ca4c

Comment 2

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

CI Results

Ran 14 Firefox configurations based on mozilla-central, and Firefox, Chrome, and Safari on GitHub CI

Total 1 tests

Status Summary

Firefox

PASS: 1

Chrome

PASS: 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/e0cc48e25e75
[wpt PR 26247] - Propagate previous fragment's break token for OOF fragmentation layout, a=testonly

Comment 4

[Razvan Maries]

https://hg.mozilla.org/mozilla-central/rev/e0cc48e25e75