Bug 249206

Summary:	[margin-trim] Implement margin trim for block containers
Product:	WebKit	Reporter:	Sammy Gill <sgill26>
Component:	Layout and Rendering	Assignee:	Sammy Gill <sgill26>
Status:	RESOLVED FIXED
Severity:	Normal	CC:	bfulgham, simon.fraser, webkit-bug-importer, zalan
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified
See Also:	https://github.com/web-platform-tests/wpt/pull/37652

Description Sammy Gill 2022-12-12 22:26:09 PST

For block containers specifically, margin-trim discards:

- The block-start margin of a block-level first child, when trimming at the block-start edge.
- The block-end margin of a block-level last child, when trimming at the block-end edge.
- Any margin collapsed with these margins.

https://w3c.github.io/csswg-drafts/css-box-4/#margin-trim-block

Comment 1 Radar WebKit Bug Importer 2022-12-12 22:26:43 PST

<rdar://problem/103285722>

Comment 2 Sammy Gill 2022-12-19 16:21:01 PST

Pull request: https://github.com/WebKit/WebKit/pull/7882

Comment 3 EWS 2023-01-04 16:35:46 PST

Committed 258457@main (6bd29f7cff74): <https://commits.webkit.org/258457@main>

Reviewed commits have been landed. Closing PR #7882 and removing active labels.