Closed Bug 1693326 Opened 3 years ago Closed 3 years ago

[wpt-sync] Sync PR 27660 - Allow fragmentainers with zero block-size.

Categories

(Core :: Layout, task, P4)

Product:
Core
Component:
Layout
Type:
task

Tracking

()

Status:
RESOLVED FIXED
Milestone:
88 Branch
Tracking Flags:
Tracking Status
firefox88 --- fixed

People

(Reporter: mozilla.org, Unassigned)

References

(
URL
)

Details

(Whiteboard: [wptsync downstream])

Sync web-platform-tests PR 27660 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/27660
Details from upstream follow.

b'Morten Stenshorne <mstensho@chromium.org>' wrote:

Allow fragmentainers with zero block-size.

The spec [1] says that fragmentainers are assumed to have a minimum
block-size of 1px regardless of their used size, in order to guarantee
content progress. We implemented this by simply making sure that the
used block-size of a fragmentainer would never become less than 1px. But
this wasn't ideal, as that would contribute to unwanted layout overflow
in cases where the content of the multicol container was shorter than
1px.

We'll now still accept at least 1px of content into each fragmentainer,
but don't stretch the fragmentainer itself (just allow the actual column
fragments to become that short as they want, and instead let the content
overflow the columns if necessary).

We still need to fill at least 1px of content before moving to the next
fragmentainer, and fast/multicol/zero-height-with-children.html is a
good test for this.

[1] https://www.w3.org/TR/css-break-3/#breaking-rules

Bug: 829028
Change-Id: I7b4e69524288dad8bb10fd10c715339d1769815a
Reviewed-on: https://chromium-review.googlesource.com/2698554
WPT-Export-Revision: 087d304644ea8b22087942321c45ecdf0daa8950

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 1 tests and 1 subtests

Status Summary

Firefox

OK : 1
PASS: 1

Chrome

OK : 1
PASS: 1

Safari

OK : 1
PASS: 1

Links

GitHub PR Head
GitHub PR Base

Pushed by wptsync@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/2fad8f2084f7
[wpt PR 27660] - Allow fragmentainers with zero block-size., a=testonly
Pushed by wptsync@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/9f48c8adebdd
[wpt PR 27660] - Allow fragmentainers with zero block-size., a=testonly
Pushed by wptsync@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/2554b6a4ebfa
[wpt PR 27660] - Allow fragmentainers with zero block-size., a=testonly

https://hg.mozilla.org/mozilla-central/rev/2554b6a4ebfa

Status: NEW → RESOLVED
Closed: 3 years ago
status-firefox88: --- → fixed
Resolution: --- → FIXED
Target Milestone: --- → 88 Branch
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