From 3c41bdbf9211c2722b45495932549a153c57a284 Mon Sep 17 00:00:00 2001
From: Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
Date: Tue, 21 Jan 2025 16:40:57 +0100
Subject: [PATCH] LibWeb: Optimize style invalidation for presentational hint
 attributes

Use invalidation sets for presentational hint attribute invalidation
instead of falling back to full descendants and siblings invalidation.
The only difference for presentational hint attributes is that we always
have to invalidate the style of element itself.
---
 Libraries/LibWeb/DOM/Element.cpp | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/Libraries/LibWeb/DOM/Element.cpp b/Libraries/LibWeb/DOM/Element.cpp
index 36ca42019a2..12b8c28912e 100644
--- a/Libraries/LibWeb/DOM/Element.cpp
+++ b/Libraries/LibWeb/DOM/Element.cpp
@@ -1970,13 +1970,12 @@ ErrorOr<void> Element::scroll_into_view(Optional<Variant<bool, ScrollIntoViewOpt
 
 void Element::invalidate_style_after_attribute_change(FlyString const& attribute_name, Optional<String> const& old_value, Optional<String> const& new_value)
 {
+    Vector<CSS::InvalidationSet::Property, 1> changed_properties;
+    ForceSelfStyleInvalidation force_self_invalidation = ForceSelfStyleInvalidation::No;
     if (is_presentational_hint(attribute_name)) {
-        invalidate_style(StyleInvalidationReason::ElementAttributeChange);
-        return;
+        force_self_invalidation = ForceSelfStyleInvalidation::Yes;
     }
 
-    Vector<CSS::InvalidationSet::Property> changed_properties;
-    ForceSelfStyleInvalidation force_self_invalidation = ForceSelfStyleInvalidation::No;
     if (attribute_name == HTML::AttributeNames::style) {
         force_self_invalidation = ForceSelfStyleInvalidation::Yes;
         changed_properties.append({ .type = CSS::InvalidationSet::Property::Type::Attribute, .value = HTML::AttributeNames::style });