From d8e80718d7fe3e7ecf30c0960a8731fa5c6e9c00 Mon Sep 17 00:00:00 2001
From: norbiros <norbiros@protonmail.com>
Date: Tue, 28 Oct 2025 11:05:31 +0100
Subject: [PATCH] LibWeb/CSS: Absolutize values while computing font variation
 settings

Makes the `compute_font_variation_settings` function match other
`compute_font_*` by absolutizing values passed into them. It resolves a
crash related to using `siblings-count` inside `font-variation-settings`

Co-authored-by: Sam Atkins <sam@ladybird.org>
---
 Libraries/LibWeb/CSS/StyleComputer.cpp | 12 ++++++++++--
 Libraries/LibWeb/CSS/StyleComputer.h   |  2 +-
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/Libraries/LibWeb/CSS/StyleComputer.cpp b/Libraries/LibWeb/CSS/StyleComputer.cpp
index 27fbf041fd4..643592cac7c 100644
--- a/Libraries/LibWeb/CSS/StyleComputer.cpp
+++ b/Libraries/LibWeb/CSS/StyleComputer.cpp
@@ -2008,6 +2008,12 @@ void StyleComputer::compute_font(ComputedProperties& style, Optional<DOM::Abstra
         PropertyID::FontStyle,
         compute_font_style(font_style_specified_value, font_computation_context));
 
+    auto const& font_variation_settings_value = style.property(PropertyID::FontVariationSettings, ComputedProperties::WithAnimationsApplied::No);
+
+    style.set_property_without_modifying_flags(
+        PropertyID::FontVariationSettings,
+        compute_font_variation_settings(font_variation_settings_value, font_computation_context));
+
     auto const& font_family = style.property(CSS::PropertyID::FontFamily);
 
     auto font_list = compute_font_for_style_values(font_family, style.font_size(), style.font_slope(), style.font_weight(), style.font_width(), style.font_variation_settings().value_or({}), font_computation_context.length_resolution_context);
@@ -3147,7 +3153,7 @@ NonnullRefPtr<StyleValue const> StyleComputer::compute_value_of_property(
     case PropertyID::CornerTopRightShape:
         return compute_corner_shape(absolutized_value);
     case PropertyID::FontVariationSettings:
-        return compute_font_variation_settings(absolutized_value);
+        return compute_font_variation_settings(absolutized_value, computation_context);
     case PropertyID::LetterSpacing:
     case PropertyID::WordSpacing:
         if (absolutized_value->to_keyword() == Keyword::Normal)
@@ -3194,8 +3200,10 @@ NonnullRefPtr<StyleValue const> StyleComputer::compute_animation_name(NonnullRef
     });
 }
 
-NonnullRefPtr<StyleValue const> StyleComputer::compute_font_variation_settings(NonnullRefPtr<StyleValue const> const& absolutized_value)
+NonnullRefPtr<StyleValue const> StyleComputer::compute_font_variation_settings(NonnullRefPtr<StyleValue const> const& specified_value, ComputationContext const& computation_context)
 {
+    auto const& absolutized_value = specified_value->absolutized(computation_context);
+
     if (absolutized_value->is_keyword())
         return absolutized_value;
 
diff --git a/Libraries/LibWeb/CSS/StyleComputer.h b/Libraries/LibWeb/CSS/StyleComputer.h
index bc5ecd1076c..7b33345c904 100644
--- a/Libraries/LibWeb/CSS/StyleComputer.h
+++ b/Libraries/LibWeb/CSS/StyleComputer.h
@@ -207,7 +207,7 @@ public:
     static NonnullRefPtr<StyleValue const> compute_font_style(NonnullRefPtr<StyleValue const> const& specified_value, ComputationContext const&);
     static NonnullRefPtr<StyleValue const> compute_font_weight(NonnullRefPtr<StyleValue const> const& specified_value, double inherited_font_weight, ComputationContext const&);
     static NonnullRefPtr<StyleValue const> compute_font_width(NonnullRefPtr<StyleValue const> const& specified_value, ComputationContext const&);
-    static NonnullRefPtr<StyleValue const> compute_font_variation_settings(NonnullRefPtr<StyleValue const> const& absolutized_value);
+    static NonnullRefPtr<StyleValue const> compute_font_variation_settings(NonnullRefPtr<StyleValue const> const& specified_value, ComputationContext const&);
     static NonnullRefPtr<StyleValue const> compute_line_height(NonnullRefPtr<StyleValue const> const& specified_value, ComputationContext const&);
     static NonnullRefPtr<StyleValue const> compute_opacity(NonnullRefPtr<StyleValue const> const& absolutized_value);
     static NonnullRefPtr<StyleValue const> compute_position_area(NonnullRefPtr<StyleValue const> const& absolutized_value);