[webkit-changes] [WebKit/WebKit] f8abf9: Style change unnecessarily computed as Change::Non...

[Antti Koivisto]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: f8abf9a2314916899adc105dfe8cbeab30cbd797
      https://github.com/WebKit/WebKit/commit/f8abf9a2314916899adc105dfe8cbeab30cbd797
  Author: Antti Koivisto <antti at apple.com>
  Date:   2023-03-27 (Mon, 27 Mar 2023)

  Changed paths:
    M LayoutTests/fast/css/mask-box-image-parsing-expected.txt
    M Source/WebCore/style/StyleAdjuster.cpp
    M Source/WebCore/style/StyleChange.cpp

  Log Message:
  -----------
  Style change unnecessarily computed as Change::NonInherited when nothing changes
https://bugs.webkit.org/show_bug.cgi?id=254426
<rdar://problem/107188441>

Reviewed by Alan Baradlay.

* Source/WebCore/style/StyleAdjuster.cpp:
(WebCore::Style::Adjuster::propagateToDocumentElementAndInitialContainingBlock):

The change here was computed against the style itself in some cases, leading to a wrong Change::None result.

* Source/WebCore/style/StyleChange.cpp:
(WebCore::Style::determineChange):

This code was return Change::NonInherited instead of Change::None because all elements
matches ::marker pseudo-element (so the bit is set) but its style is only computed if needed.

The whole pseudo-element testing part here is an unnecessary left-over. Pseudo-element changes are
checked when their values are actually computed.

Canonical link: https://commits.webkit.org/262148@main