315483 2026-05-24 19:46:53 -0700 Refactor container-type into a Style value type 2026-05-25 23:21:13 -0700 1 1 1 Unclassified WebKit CSS WebKit Nightly Build All All RESOLVED FIXED InRadar P2 Normal --- 1 klee webkit-unassigned koivisto webkit-bug-importer oldest_to_newest 2213736 0 klee 2026-05-24 19:46:53 -0700 The container-type property's computed value is currently represented by the ContainerType enum (normal | size | inline-size), stored as a 2-bit bitfield in StyleNonInheritedRareData and converted to/from CSS via the generated 1:1 keyword <-> CSSValueID mapping. css-conditional-5 redefines the grammar as: container-type = normal | [ [ size | inline-size ] || scroll-state ] https://drafts.csswg.org/css-conditional-5/#container-type The `||` combinator means scroll-state can be combined with size or inline-size (e.g. "size scroll-state", "inline-size scroll-state"). A combined value parses to a CSSValuePair of two keywords, and its computed value must serialize back to two keywords. The generated enum storage relies on a single keyword <-> single enum value mapping for both parsing and computed-value serialization, so it cannot represent or round-trip a combined value. container-type can therefore no longer be a plain enum. This bug covers the preparatory, non-functional refactor: migrate container-type to a Style::ContainerType value type (computed-style-storage-kind "reference") with a custom CSSValueConversion and switchOn, matching the sibling properties stored in the same struct (scrollbar-gutter -> Style::ScrollbarGutter, scroll-snap-type -> Style::ScrollSnapType). Only normal, size and inline-size are supported in this change -- there is no behavior change. The scroll-state value itself, including the combined forms and the feature flag, will be added on top in bug 314082. 2213737 1 klee 2026-05-24 19:55:42 -0700 Pull request: https://github.com/WebKit/WebKit/pull/65594 2214022 2 ews-feeder 2026-05-25 23:20:56 -0700 Committed 313869@main (d9dde2e0b6ed): <https://commits.webkit.org/313869@main> Reviewed commits have been landed. Closing PR #65594 and removing active labels. 2214023 3 webkit-bug-importer 2026-05-25 23:21:13 -0700 <rdar://problem/177921550>