[webkit-changes] [WebKit/WebKit] 1bb6a5: Cherry-pick 259548.8 at safari-7615-branch (5a0f792b0...

[JC Alvarado]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 1bb6a599c3aef0843ff171cb156f008ae1c634a0
      https://github.com/WebKit/WebKit/commit/1bb6a599c3aef0843ff171cb156f008ae1c634a0
  Author: JC Alvarado <joncarlo at apple.com>
  Date:   2023-03-28 (Tue, 28 Mar 2023)

  Changed paths:
    A LayoutTests/fast/backgrounds/background-color-lch-crash-expected.txt
    A LayoutTests/fast/backgrounds/background-color-lch-crash.html
    M Source/WebCore/platform/graphics/ColorBlending.cpp

  Log Message:
  -----------
  Cherry-pick 259548.8 at safari-7615-branch (5a0f792b008f). rdar://107333395

    Check color opacity after lossy conversion when blending
    https://bugs.webkit.org/show_bug.cgi?id=251158
    rdar://104553839

    Reviewed by Dean Jackson.

    We check opacity to determine if we should forgo blending,
    however after performing a lossy conversion we can end
    up with alpha values that result in a division by zero.
    Add an additional check after conversion to prevent this
    case.

    * LayoutTests/fast/backgrounds/background-color-lch-crash-expected.txt: Added.
    * LayoutTests/fast/backgrounds/background-color-lch-crash.html: Added.
    * Source/WebCore/platform/graphics/ColorBlending.cpp:
    (WebCore::blendSourceOver):

    Canonical link: https://commits.webkit.org/259548.8@safari-7615-branch

Canonical link: https://commits.webkit.org/262245@main