Bug 227624 – REGRESSION (r278377): incorrect hit-testing with clip-path()

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

[Antoine Quint]

Created attachment 432788 [details]
test

The attached test case regressed with r278377 in that the cursor set via CSS on an element with a clip-path and a hierarchy of element with display: flex and clip-path above it fails to show the cursor.

[Antoine Quint]

<rdar://problem/79845896>

[Antoine Quint]

The test case shows the intermediate container is the one being hit-tested since the wait cursor is shown when hovering over the black rectangle.

[Antoine Quint]

We fail this check in Path::contains() under this call stack when consider the RenderLayer for the "leaf" element:

    if (!fastBoundingRect().contains(point))
        return false;

#0	0x000000073c986373 in WebCore::Path::contains(WebCore::FloatPoint const&, WebCore::WindRule) const at WebCore/platform/graphics/cg/PathCG.cpp:227
#1	0x000000073cdca823 in WebCore::RenderBox::hitTestClipPath(WebCore::HitTestLocation const&, WebCore::LayoutPoint const&) const at WebCore/rendering/RenderBox.cpp:1388
#2	0x000000073ceba871 in WebCore::RenderLayer::hitTestLayer(WebCore::RenderLayer*, WebCore::RenderLayer*, WebCore::HitTestRequest const&, WebCore::HitTestResult&, WebCore::LayoutRect const&, WebCore::HitTestLocation const&, bool, WebCore::HitTestingTransformState const*, double*) at WebCore/rendering/RenderLayer.cpp:4122

The provided point is indeed outside of the bounds and seems to be in page coordinates, or at least converted to the coordinates of this element.

[Simon Fraser (smfr)]

Created attachment 432805 [details]
More self-explanatory, non-flex testcase

[zalan]

Created attachment 432818 [details]
Another test reduction

[zalan]

Created attachment 432839 [details]
Patch

[Simon Fraser (smfr)]

Comment on attachment 432839 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=432839&action=review

> Source/WebCore/ChangeLog:13
> +        3. The clip-path instersecting takes coordinates relative to the containing block.

"instersecting"

[zalan]

Created attachment 432851 [details]
Patch

[EWS]

Committed r279544 (239380@main): <https://commits.webkit.org/239380@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 432851 [details].

[Simon Fraser (smfr)]

*** Bug 228262 has been marked as a duplicate of this bug. ***