Closed Bug 1722052 Opened 4 years ago Closed 4 years ago

[wpt-sync] Sync PR 29766 - [LayoutNG] Relative offsets and nested fixedpos elements in a multicol

Categories

(Core :: Layout, task, P4)

Product:
Core
Component:
Layout
Type:
task

Tracking

()

Status:
RESOLVED FIXED
Milestone:
92 Branch
Tracking Flags:
Tracking Status
firefox92 --- fixed

People

(Reporter: wpt-sync, Unassigned)

References

(
URL
)

Details

(Whiteboard: [wptsync downstream])

Sync web-platform-tests PR 29766 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/29766
Details from upstream follow.

b'Alison Maher <almaher@microsoft.com>' wrote:

[LayoutNG] Relative offsets and nested fixedpos elements in a multicol

The static position of a nested fixedpos in a multicol was not affected
by the relative offset of its ancestor, specifically any relative
offset that occurred before the fixedpos reached its CB. To fix this,
calculate the relative offset that exists between the fixedpos and its
CB, and apply that relative offset to the static position of the
fixedpos descendant.

Note that unlike the relative offset that occurs within the fixedpos'
containing block chain, this relative offset is getting applied to
the static position before fragmentation takes place. The reason being
that we would have otherwise needed to store a separate relative offset
for this case that would be applied after fragmentation, but only if
the final offset of the fixedpos was affected by its static position.
Applying the relative offset before fragmentation in this case matches
Firefox's behavior and seems to make more sense conceptually.

Bug: 1218313
Change-Id: Id1aea608f2406cda061418e9ea8c6f9f5e01cd86
Reviewed-on: https://chromium-review.googlesource.com/3045640
WPT-Export-Revision: c695fcccc306a79b14db93183e15ebe4d6a9a9f1

Component: web-platform-tests → Layout
Product: Testing → Core

CI Results

Ran 0 Firefox configurations based on mozilla-central, and Firefox, Chrome, and Safari on GitHub CI

Total 2 tests

Status Summary

Firefox

FAIL: 2

Chrome

FAIL: 2

Safari

FAIL: 2

Links

GitHub PR Head
GitHub PR Base

Details

New Tests That Don't Pass

/css/css-break/out-of-flow-in-multicolumn-044.html: FAIL (Chrome: FAIL, Safari: FAIL)
/css/css-break/out-of-flow-in-multicolumn-073.html: FAIL (Chrome: FAIL, Safari: FAIL)

Pushed by wptsync@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/c0a828e66bb5 [wpt PR 29766] - [LayoutNG] Relative offsets and nested fixedpos elements in a multicol, a=testonly https://hg.mozilla.org/integration/autoland/rev/896d0d0930b3 [wpt PR 29766] - Update wpt metadata, a=testonly

https://hg.mozilla.org/mozilla-central/rev/c0a828e66bb5
https://hg.mozilla.org/mozilla-central/rev/896d0d0930b3

Status: NEW → RESOLVED
Closed: 4 years ago
status-firefox92: --- → fixed
Resolution: --- → FIXED
Target Milestone: --- → 92 Branch
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