1725002 - [wpt-sync] Sync PR 29972 - [LayoutNG] Break token for new column before spanner

Status: RESOLVED FIXED

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

Description

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

Sync web-platform-tests PR 29972 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/29972
Details from upstream follow.

b'Alison Maher <[e-mail]>' wrote:

[LayoutNG] Break token for new column before spanner

In CL:3018723, logic was added to the column layout algorithm to lay
out any OOF descendants when we find a spanner to ensure that any OOF
descendants found before a spanner are actually laid out before the
spanner.

If a new column was created for an OOF before the spanner, we wouldn't
end up creating a column break token for that new column if the OOF
didn't break. This CL adds logic to NGSimplifiedOOFLayoutAlgorithm to
make sure that a break token is created for the column in this case.

Additionally, if any columns are added after the spanner, we would end
up crashing because the new column created for the OOF was not
taken into account when adding the subsequent column (i.e. the
sequence number and consumed block size were incorrect, and
the subsequent column was added to the flow thread at the wrong
index).

To fix this, continue using the previous column break token to
resume column layout, but store a column break token for the
column added for the OOF in MulticolPartWalker. This column
break token will be used when writing back to legacy to ensure
the subsequent column break token has the correct sequence number
and consumed block size, and that the correct index is calculated
when writing that column back to legacy.

Bug: 1237247
Change-Id: I55c73fc36a604e858dde5859f65a1ca66023e54a
Reviewed-on: https://chromium-review.googlesource.com/3082315
WPT-Export-Revision: e6b1ae85081898a8ecfcaecd97da4a54af60638a

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=560c51e75f2ec6efed41d7c85c9e463ca0f8a690

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/6e2e6d13deda
[wpt PR 29972] - [LayoutNG] Break token for new column before spanner, a=testonly

Comment 3

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

Test result changes from PR not available.

Comment 4

[Iulian Moraru]

https://hg.mozilla.org/mozilla-central/rev/6e2e6d13deda