[webkit-changes] [WebKit/WebKit] 9565d9: Null ptr deref in CSSStyleSheet::replaceSync.

[Arunsundar Kannan]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 9565d92681d724cfb509da570d98241ab6263272
      https://github.com/WebKit/WebKit/commit/9565d92681d724cfb509da570d98241ab6263272
  Author: Arunsundar Kannan <arunsundar_kannan at apple.com>
  Date:   2023-05-22 (Mon, 22 May 2023)

  Changed paths:
    A LayoutTests/imported/w3c/web-platform-tests/css/cssom/css-stylesheet-replaceSync-null-deref-expected.txt
    A LayoutTests/imported/w3c/web-platform-tests/css/cssom/css-stylesheet-replaceSync-null-deref.html
    M Source/WebCore/css/CSSStyleSheet.cpp

  Log Message:
  -----------
  Null ptr deref in CSSStyleSheet::replaceSync.
https://bugs.webkit.org/show_bug.cgi?id=254727.
rdar://101629411.

Reviewed by Chris Dumez.

Added a null check in CSSStyleSheet::replaceSync to prevent a null deref.

* LayoutTests/imported/w3c/web-platform-tests/css/cssom/css-stylesheet-replaceSync-null-deref-expected.txt: Added.
* LayoutTests/imported/w3c/web-platform-tests/css/cssom/css-stylesheet-replaceSync-null-deref.html: Added.
* Source/WebCore/css/CSSStyleSheet.cpp:
(WebCore::CSSStyleSheet::replaceSync):

Originally-landed-as: 259548.524 at safari-7615-branch (a48f8590fa3e). rdar://101629411
Canonical link: https://commits.webkit.org/264358@main