From d10eaa996eef125671874207798b8b61bd793846 Mon Sep 17 00:00:00 2001
From: Sam Atkins <sam@ladybird.org>
Date: Thu, 28 Aug 2025 12:14:15 +0100
Subject: [PATCH] LibWeb/CSS: Use empty optional for `stretch` in FitContentSV

...instead of using an `auto` Length.
---
 Libraries/LibWeb/CSS/ComputedProperties.cpp          |  4 +++-
 Libraries/LibWeb/CSS/Parser/ValueParsing.cpp         |  2 ++
 .../LibWeb/CSS/StyleValues/FitContentStyleValue.h    | 12 ++++++------
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/Libraries/LibWeb/CSS/ComputedProperties.cpp b/Libraries/LibWeb/CSS/ComputedProperties.cpp
index c0ba3b49ef4..9ed0fbecab4 100644
--- a/Libraries/LibWeb/CSS/ComputedProperties.cpp
+++ b/Libraries/LibWeb/CSS/ComputedProperties.cpp
@@ -198,7 +198,9 @@ Size ComputedProperties::size_value(PropertyID id) const
     }
     if (value.is_fit_content()) {
         auto& fit_content = value.as_fit_content();
-        return Size::make_fit_content(fit_content.length_percentage());
+        if (auto length_percentage = fit_content.length_percentage(); length_percentage.has_value())
+            return Size::make_fit_content(length_percentage.release_value());
+        return Size::make_fit_content();
     }
 
     if (value.is_calculated())
diff --git a/Libraries/LibWeb/CSS/Parser/ValueParsing.cpp b/Libraries/LibWeb/CSS/Parser/ValueParsing.cpp
index 0d70dc19ee9..b911ed03dc6 100644
--- a/Libraries/LibWeb/CSS/Parser/ValueParsing.cpp
+++ b/Libraries/LibWeb/CSS/Parser/ValueParsing.cpp
@@ -3192,6 +3192,8 @@ RefPtr<FitContentStyleValue const> Parser::parse_fit_content_value(TokenStream<C
         return nullptr;
 
     transaction.commit();
+    if (maybe_length->is_auto())
+        return FitContentStyleValue::create();
     return FitContentStyleValue::create(maybe_length.release_value());
 }
 
diff --git a/Libraries/LibWeb/CSS/StyleValues/FitContentStyleValue.h b/Libraries/LibWeb/CSS/StyleValues/FitContentStyleValue.h
index dc81675c4fa..021035f75de 100644
--- a/Libraries/LibWeb/CSS/StyleValues/FitContentStyleValue.h
+++ b/Libraries/LibWeb/CSS/StyleValues/FitContentStyleValue.h
@@ -15,7 +15,7 @@ class FitContentStyleValue final : public StyleValue {
 public:
     static ValueComparingNonnullRefPtr<FitContentStyleValue const> create()
     {
-        return adopt_ref(*new (nothrow) FitContentStyleValue(LengthPercentage { Length::make_auto() }));
+        return adopt_ref(*new (nothrow) FitContentStyleValue());
     }
     static ValueComparingNonnullRefPtr<FitContentStyleValue const> create(LengthPercentage length_percentage)
     {
@@ -25,9 +25,9 @@ public:
 
     virtual String to_string(SerializationMode mode) const override
     {
-        if (m_length_percentage.is_auto())
+        if (!m_length_percentage.has_value())
             return "fit-content"_string;
-        return MUST(String::formatted("fit-content({})", m_length_percentage.to_string(mode)));
+        return MUST(String::formatted("fit-content({})", m_length_percentage->to_string(mode)));
     }
 
     bool equals(StyleValue const& other) const override
@@ -37,16 +37,16 @@ public:
         return m_length_percentage == other.as_fit_content().m_length_percentage;
     }
 
-    [[nodiscard]] LengthPercentage const& length_percentage() const { return m_length_percentage; }
+    [[nodiscard]] Optional<LengthPercentage> const& length_percentage() const { return m_length_percentage; }
 
 private:
-    FitContentStyleValue(LengthPercentage length_percentage)
+    FitContentStyleValue(Optional<LengthPercentage> length_percentage = {})
         : StyleValue(Type::FitContent)
         , m_length_percentage(move(length_percentage))
     {
     }
 
-    LengthPercentage m_length_percentage;
+    Optional<LengthPercentage> m_length_percentage;
 };
 
 }