[webkit-changes] [WebKit/WebKit] 19bafb: [threaded-animation-resolution] animating `filter:...

[Antoine Quint]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 19bafb54016f558761e4510df10069d4194b5e2c
      https://github.com/WebKit/WebKit/commit/19bafb54016f558761e4510df10069d4194b5e2c
  Author: Antoine Quint <graouts at webkit.org>
  Date:   2024-02-15 (Thu, 15 Feb 2024)

  Changed paths:
    M Source/WebCore/platform/graphics/ca/cocoa/PlatformCAFiltersCocoa.mm

  Log Message:
  -----------
  [threaded-animation-resolution] animating `filter: drop-shadow()` crashes the UIProcess
https://bugs.webkit.org/show_bug.cgi?id=269453

Reviewed by Dean Jackson.

We need to increase the presentation modifier list index prior to accessing the next
modifier when we're dealing with a `drop-shadow()` operation, otherwise we'd access
the `shadowOffset` presentation modifier to set the `shadowColor`, which of course
would lead an incorrect result, but more importantly yields an exception because
of mismatching value types.

* Source/WebCore/platform/graphics/ca/cocoa/PlatformCAFiltersCocoa.mm:
(WebCore::PlatformCAFilters::updatePresentationModifiers):

Canonical link: https://commits.webkit.org/274759@main