Bug 233171 – SVG: Do not apply text-decoration on elements with display:contents

• Status: RESOLVED
• Resolution: FIXED
• Component: SVG

[Tim Nguyen (:ntim)]

Port https://chromium-review.googlesource.com/c/chromium/src/+/3192872

It's already done for non-SVG elements, SVG should match.

Test: imported/w3c/web-platform-tests/css/css-text-decor/text-decoration-propagation-display-contents.html

[Radar WebKit Bug Importer]

<rdar://problem/85691104>

[Karl Dubost]

css-text-decor §line-decoration (https://drafts.csswg.org/css-text-decor/#line-decoration) — "Line decorations are propagated through the box tree, not through inheritance"

WebKit propagates text-decoration-line-in-effect from a display: contents element to its descendants. Since that element generates no box, it shouldn't  act as a decoration source.

Source/WebCore/style/StyleAdjuster.cpp:162-172 — shouldInheritTextDecorationsInEffect switches on style.display().value and returns false for InlineFlowRoot, InlineTable, InlineFlex, InlineGrid, InlineGridLanes, InlineDeprecatedFlex. DisplayType::Contents is missing from the list. As a result, line 637-640 of StyleAdjuster.cpp ORs the display:contents element's text-decoration-line into the inherited textDecorationLineInEffect, which descendants then paint.
  
Fix sketch: add case DisplayType::Contents: return false; to the switch.

[Ahmad Saleem]

Pull request: https://github.com/WebKit/WebKit/pull/66515

[EWS]

Committed 314830@main (f149be78a28f): <https://commits.webkit.org/314830@main>

Reviewed commits have been landed. Closing PR #66515 and removing active labels.

[Ahmad Saleem]

Submitted web-platform-tests pull request: https://github.com/web-platform-tests/wpt/pull/60767