LibWeb: Route presentational hints through the CSS cascade

Previously, presentational hints bypassed the regular cascade pipeline
and wrote directly into `CascadedProperties` under
`CascadeOrigin::Author`. That meant `var()` substitution and the
invalid-at-computed-value-time fallback had to be duplicated in a
separate per-element pass, which in practice missed the IACVT step and
could leave a `GuaranteedInvalidStyleValue` in the cascaded
properties. This caused a crash in downstream code that assumed the
value had been resolved.

This introduces an `AuthorPresentationalHint` cascade origin and feeds
them through the cascade as normal declarations. This means that
`var()` resolution now happens in only one place.
This commit is contained in:
Tim Ledbetter
2026-04-30 10:44:26 +01:00
committed by Sam Atkins
parent 297b1af9bf
commit d1fc4b4234
Notes: github-actions[bot] 2026-04-30 18:51:41 +00:00
67 changed files with 316 additions and 374 deletions

View File

@@ -6,7 +6,6 @@
#include <LibWeb/Bindings/HTMLTableColElement.h>
#include <LibWeb/Bindings/Intrinsics.h>
#include <LibWeb/CSS/CascadedProperties.h>
#include <LibWeb/CSS/ComputedProperties.h>
#include <LibWeb/HTML/HTMLTableColElement.h>
#include <LibWeb/HTML/Numbers.h>
@@ -60,15 +59,14 @@ bool HTMLTableColElement::is_presentational_hint(FlyString const& name) const
return name == HTML::AttributeNames::width;
}
void HTMLTableColElement::apply_presentational_hints(GC::Ref<CSS::CascadedProperties> cascaded_properties) const
void HTMLTableColElement::apply_presentational_hints(Vector<CSS::StyleProperty>& properties) const
{
Base::apply_presentational_hints(cascaded_properties);
Base::apply_presentational_hints(properties);
for_each_attribute([&](auto& name, auto& value) {
// https://html.spec.whatwg.org/multipage/rendering.html#tables-2:maps-to-the-dimension-property-2
if (name == HTML::AttributeNames::width) {
if (auto parsed_value = parse_dimension_value(value)) {
cascaded_properties->set_property_from_presentational_hint(CSS::PropertyID::Width, *parsed_value);
}
if (auto parsed_value = parse_dimension_value(value))
properties.append({ .property_id = CSS::PropertyID::Width, .value = *parsed_value });
}
});
}