Bug 258740

Summary:	Fix shadow invalidation rect issue in vertical-rl mode
Product:	WebKit	Reporter:	Ahmad Saleem <ahmad.saleem792>
Component:	Layout and Rendering	Assignee:	Nobody <webkit-unassigned>
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://bugs.webkit.org/show_bug.cgi?id=264625

Description Ahmad Saleem 2023-06-30 10:19:37 PDT

Hi Team,

While going through Blink's commit, I came across another clean-up to fix shadow invalidation rects issue and don't seems to have any failing test case (in /fast/ directory).

Blink Commit: https://src.chromium.org/viewvc/blink?revision=177246&view=revision

Just wanted to raise, so I can get input, whether it is good to merge or not.

Thanks!

Comment 1 Ahmad Saleem 2023-06-30 10:22:19 PDT

WebKit Source: https://searchfox.org/wubkat/source/Source/WebCore/rendering/RenderBox.cpp#5074

Comment 2 zalan 2023-07-03 06:24:39 PDT

I'd look at the history of those flipped lines to see why we originally thought they needed flipping. Blink's commit message does not explain that (it just says it's erroneous)

Comment 3 Ahmad Saleem 2023-07-03 06:32:26 PDT

(In reply to zalan from comment #2)
> I'd look at the history of those flipped lines to see why we originally
> thought they needed flipping. Blink's commit message does not explain that
> (it just says it's erroneous)

Original bugs refer this:

Shadows and border images should be unrelated to writing-mode. Should not flip the edges when invalidating them despite writing-mode.

and in spec:

https://drafts.csswg.org/css-writing-modes-3/#physical-only

"The following values are purely physical in their definitions and do not respond to changes in writing mode:"

-> the offsets of the box-shadow and text-shadow properties

Comment 4 Radar WebKit Bug Importer 2023-07-07 10:20:17 PDT

<rdar://problem/111915460>

Comment 5 Ahmad Saleem 2023-11-30 18:37:05 PST

I tried to look back into this and this patch added the comment:

https://bugs.webkit.org/attachment.cgi?id=106906&action=diff

Although it is not super clear to myself. Since Simon is working on 'overflow' and 'repaint rects' clean-up, I think he might have more insight.

@Simon - any insight?

Comment 6 Ahmad Saleem 2023-11-30 18:37:09 PST

I tried to look back into this and this patch added the comment:

https://bugs.webkit.org/attachment.cgi?id=106906&action=diff

Although it is not super clear to myself. Since Simon is working on 'overflow' and 'repaint rects' clean-up, I think he might have more insight.

@Simon - any insight?

Comment 7 Simon Fraser (smfr) 2023-12-01 10:29:45 PST

I think we do want to take this change.

Comment 8 EWS 2023-12-01 17:54:54 PST

Committed 271416@main (b738ab355f6e): <https://commits.webkit.org/271416@main>

Reviewed commits have been landed. Closing PR #21174 and removing active labels.