)]}'
{
  "commit": "ef00a2bc79a56bdd9cb2ac27ab3d42662f82deea",
  "tree": "96dff518bd5421e5427331089cd5aa9614048c92",
  "parents": [
    "f5ad6e77a2dbae7d3b70f31fbbf712fec767fa63"
  ],
  "author": {
    "name": "Ahmad Saleem",
    "email": "ahmad.saleem792+github@gmail.com",
    "time": "Fri May 08 17:12:51 2026"
  },
  "committer": {
    "name": "Ahmad Saleem",
    "email": "ahmad.saleem792@gmail.com",
    "time": "Fri May 08 17:12:51 2026"
  },
  "message": "sibling-index() in @keyframes doesn\u0027t re-resolve when siblings change\nhttps://bugs.webkit.org/show_bug.cgi?id\u003d314376\nrdar://176531901\n\nReviewed by Antoine Quint.\n\nWhen a keyframe value uses sibling-index() or sibling-count(), the\nresolved keyframe style is frozen at the value computed at animation\nstart. Adding or removing a preceding sibling correctly invalidates\nthe target\u0027s style (via ChildrenAffectedBy{Forward,Backward}PositionalRules),\nbut KeyframeEffect::recomputeKeyframesIfNecessary() had no signal to\nre-run styleForKeyframe, so the blended keyframe kept the stale index.\n\nTrack tree-counting usage on the keyframe style and recompute keyframes\nwhen it is set, mirroring the existing handling of usesAnchorFunctions.\n\n* Source/WebCore/animation/BlendingKeyframes.cpp:\n(WebCore::BlendingKeyframes::usesTreeCountingFunctions const):\n* Source/WebCore/animation/BlendingKeyframes.h:\n* Source/WebCore/animation/KeyframeEffect.cpp:\n(WebCore::KeyframeEffect::recomputeKeyframesIfNecessary): Recompute\nblending keyframes when they reference tree-counting functions, so the\ntarget\u0027s style invalidation on sibling change propagates through to the\nanimated value.\n\n\u003e Progressions:\n* LayoutTests/imported/w3c/web-platform-tests/css/css-values/tree-counting/sibling-index-keyframe-font-style-dynamic-expected.txt:\n* LayoutTests/imported/w3c/web-platform-tests/css/css-values/tree-counting/sibling-index-keyframe-font-variation-settings-dynamic-expected.txt:\n* LayoutTests/imported/w3c/web-platform-tests/css/css-values/tree-counting/sibling-index-keyframe-font-weight-dynamic-expected.txt:\n* LayoutTests/imported/w3c/web-platform-tests/css/css-values/tree-counting/sibling-index-keyframe-length-value-dynamic-expected.txt:\n* LayoutTests/imported/w3c/web-platform-tests/css/css-values/tree-counting/sibling-index-keyframe-registered-properties-dynamic-expected.txt:\n* LayoutTests/imported/w3c/web-platform-tests/css/css-values/tree-counting/sibling-index-keyframe-rotate-dynamic-expected.txt:\n* LayoutTests/imported/w3c/web-platform-tests/css/css-values/tree-counting/sibling-index-keyframe-scale-dynamic-expected.txt:\n* LayoutTests/imported/w3c/web-platform-tests/css/css-values/tree-counting/sibling-index-keyframe-transform-dynamic-expected.txt:\n* LayoutTests/imported/w3c/web-platform-tests/css/css-values/tree-counting/sibling-index-keyframe-value-dynamic-expected.txt:\n\nCanonical link: https://commits.webkit.org/312895@main\n",
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