[webkit-changes] [WebKit/WebKit] c13598: Make containing block of position:fixed dialog chi...

[Rob Buis]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: c13598861f4027d8876901ae7e4c2ecb8661f6d8
      https://github.com/WebKit/WebKit/commit/c13598861f4027d8876901ae7e4c2ecb8661f6d8
  Author: Rob Buis <rbuis at igalia.com>
  Date:   2022-11-16 (Wed, 16 Nov 2022)

  Changed paths:
    A LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-contain-ancestor-expected.html
    A LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-contain-ancestor.html
    A LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-fixed-position-cb-ref.html
    A LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-fo-ancestor-expected.html
    A LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-fo-ancestor.html
    A LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-transformed-ancestor-expected.html
    A LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-transformed-ancestor.html
    A LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-will-change-ancestor-expected.html
    A LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-will-change-ancestor.html
    M Source/WebCore/rendering/RenderObject.cpp

  Log Message:
  -----------
  Make containing block of position:fixed dialog children the viewport
https://bugs.webkit.org/show_bug.cgi?id=247951
rdar://99242889

Reviewed by Alan Baradlay.

Make containing block of position:fixed dialog children the viewport, since
basically the dialog is reparented to the root [1] and following
the rules for determining the fixed positioned element [2] the
viewport will be the nearest ancestor box that establishes a
fixed positioning containing block.

Add WPT tests involving alll possible dialog ancestors that can
stablish a fixed positioning containing block.

[1] https://fullscreen.spec.whatwg.org/#new-stacking-layer
[2] https://drafts.csswg.org/css-position/#fixed-cb

* LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-contain-ancestor-expected.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-contain-ancestor.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-fixed-position-cb-ref.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-fo-ancestor-expected.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-fo-ancestor.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-transformed-ancestor-expected.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-transformed-ancestor.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-will-change-ancestor-expected.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-dialog-element/fixed-position-child-with-will-change-ancestor.html: Added.
* Source/WebCore/rendering/RenderObject.cpp:
(WebCore::RenderObject::containingBlockForPositionType):
(WebCore::containerForElement):

Canonical link: https://commits.webkit.org/256724@main