Bug 258740 – Fix shadow invalidation rect issue in vertical-rl mode

• Status: RESOLVED
• Resolution: FIXED
• Component: Layout and Rendering

[Ahmad Saleem]

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!

[Ahmad Saleem]

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

[zalan]

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)

[Ahmad Saleem]

(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

[Radar WebKit Bug Importer]

<rdar://problem/111915460>

[Ahmad Saleem]

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?

[Ahmad Saleem]

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?

[Simon Fraser (smfr)]

I think we do want to take this change.

[EWS]

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

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