[webkit-changes] [WebKit/WebKit] 302813: Facebook.com: Text overlaps in videos up next sidebar

[mattwoodrow]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 3028133f11d61758e687f07e3c5b7a8ee0dd30b3
      https://github.com/WebKit/WebKit/commit/3028133f11d61758e687f07e3c5b7a8ee0dd30b3
  Author: Matt Woodrow <mattwoodrow at apple.com>
  Date:   2022-12-19 (Mon, 19 Dec 2022)

  Changed paths:
    A LayoutTests/compositing/transforms/clipping-layer-and-flattening-layer-expected.html
    A LayoutTests/compositing/transforms/clipping-layer-and-flattening-layer.html
    M Source/WebCore/rendering/RenderLayerBacking.cpp

  Log Message:
  -----------
  Facebook.com: Text overlaps in videos up next sidebar
https://bugs.webkit.org/show_bug.cgi?id=249566
<rdar://problem/103502243>

Reviewed by Simon Fraser.

The transform flattening layer was being attached as the parent of the last clipping layer in the
stack, not the first. This meant that any clipping layers before the last ended up orphaned.

* LayoutTests/compositing/transforms/clipping-layer-and-flattening-layer-expected.html: Added.
* LayoutTests/compositing/transforms/clipping-layer-and-flattening-layer.html: Added.
* Source/WebCore/rendering/RenderLayerBacking.cpp:
(WebCore::RenderLayerBacking::updateInternalHierarchy):

Canonical link: https://commits.webkit.org/258093@main