Created attachment 453128 [details] testcase Analogous to bug 237073, 'revert-layer' doesn't work in @keyframes, it just behaves as 'unset'. Note that unlike 'revert', it should roll back to author origin, not to user origin. https://drafts.csswg.org/css-cascade-5/#revert-layer
Created attachment 453142 [details] Patch
PTAL. Not sure if BuilderState is the right class to store the flag, or if it would be better in Builder or PropertyCascade.
Comment on attachment 453142 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=453142&action=review > Source/WebCore/style/StyleBuilderState.h:110 > + void setIgnoreRevertLayer() { m_ignoreRevertLayer = true; } Maybe this should be more specific like m_isBuildingKeyframeStyle as I don't think it has any other uses.
Created attachment 453595 [details] Patch
(In reply to Antti Koivisto from comment #3) > Maybe this should be more specific like m_isBuildingKeyframeStyle as I don't > think it has any other uses. Done. Also moved the comment since with the new name the explanation seemed more needed in Builder::applyProperty.
Committed r290729 (247976@main): <https://commits.webkit.org/247976@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 453595 [details].
<rdar://problem/89686640>