From 1033bf5cd2c7f3893d0f4d5d7972ed94e77c3b64 Mon Sep 17 00:00:00 2001
From: Sam Atkins <sam@ladybird.org>
Date: Tue, 8 Apr 2025 16:50:51 +0100
Subject: [PATCH] LibWeb/CSS: Allow CSSImportRule's document to be null on
 construction

It's possible to parse an `@import` rule that isn't attached to a
document. We only actually need it to have one when fetching the linked
style sheet, and that should only happen when the CSSImportRule is
attached to a document. So, we can just accept a null pointer when
constructing it.

We relied on that Document to get the Realm, so pass that in as a
separate parameter.
---
 Libraries/LibWeb/CSS/CSSImportRule.cpp      | 11 +++++------
 Libraries/LibWeb/CSS/CSSImportRule.h        |  4 ++--
 Libraries/LibWeb/CSS/Parser/RuleParsing.cpp |  2 +-
 3 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/Libraries/LibWeb/CSS/CSSImportRule.cpp b/Libraries/LibWeb/CSS/CSSImportRule.cpp
index 7e20b09ea3c..adac6310417 100644
--- a/Libraries/LibWeb/CSS/CSSImportRule.cpp
+++ b/Libraries/LibWeb/CSS/CSSImportRule.cpp
@@ -23,17 +23,16 @@ namespace Web::CSS {
 
 GC_DEFINE_ALLOCATOR(CSSImportRule);
 
-GC::Ref<CSSImportRule> CSSImportRule::create(::URL::URL url, DOM::Document& document, RefPtr<Supports> supports, Vector<NonnullRefPtr<MediaQuery>> media_query_list)
+GC::Ref<CSSImportRule> CSSImportRule::create(JS::Realm& realm, ::URL::URL url, GC::Ptr<DOM::Document> document, RefPtr<Supports> supports, Vector<NonnullRefPtr<MediaQuery>> media_query_list)
 {
-    auto& realm = document.realm();
-    return realm.create<CSSImportRule>(move(url), document, supports, move(media_query_list));
+    return realm.create<CSSImportRule>(realm, move(url), document, move(supports), move(media_query_list));
 }
 
-CSSImportRule::CSSImportRule(::URL::URL url, DOM::Document& document, RefPtr<Supports> supports, Vector<NonnullRefPtr<MediaQuery>> media_query_list)
-    : CSSRule(document.realm(), Type::Import)
+CSSImportRule::CSSImportRule(JS::Realm& realm, ::URL::URL url, GC::Ptr<DOM::Document> document, RefPtr<Supports> supports, Vector<NonnullRefPtr<MediaQuery>> media_query_list)
+    : CSSRule(realm, Type::Import)
     , m_url(move(url))
     , m_document(document)
-    , m_supports(supports)
+    , m_supports(move(supports))
     , m_media_query_list(move(media_query_list))
 {
 }
diff --git a/Libraries/LibWeb/CSS/CSSImportRule.h b/Libraries/LibWeb/CSS/CSSImportRule.h
index 4426b156787..72df3a1d2cb 100644
--- a/Libraries/LibWeb/CSS/CSSImportRule.h
+++ b/Libraries/LibWeb/CSS/CSSImportRule.h
@@ -21,7 +21,7 @@ class CSSImportRule final
     GC_DECLARE_ALLOCATOR(CSSImportRule);
 
 public:
-    [[nodiscard]] static GC::Ref<CSSImportRule> create(::URL::URL, DOM::Document&, RefPtr<Supports>, Vector<NonnullRefPtr<MediaQuery>>);
+    [[nodiscard]] static GC::Ref<CSSImportRule> create(JS::Realm&, ::URL::URL, GC::Ptr<DOM::Document>, RefPtr<Supports>, Vector<NonnullRefPtr<MediaQuery>>);
 
     virtual ~CSSImportRule() = default;
 
@@ -37,7 +37,7 @@ public:
     Optional<String> supports_text() const;
 
 private:
-    CSSImportRule(::URL::URL, DOM::Document&, RefPtr<Supports>, Vector<NonnullRefPtr<MediaQuery>>);
+    CSSImportRule(JS::Realm&, ::URL::URL, GC::Ptr<DOM::Document>, RefPtr<Supports>, Vector<NonnullRefPtr<MediaQuery>>);
 
     virtual void initialize(JS::Realm&) override;
     virtual void visit_edges(Cell::Visitor&) override;
diff --git a/Libraries/LibWeb/CSS/Parser/RuleParsing.cpp b/Libraries/LibWeb/CSS/Parser/RuleParsing.cpp
index 4f511e1ade5..aed7a88923b 100644
--- a/Libraries/LibWeb/CSS/Parser/RuleParsing.cpp
+++ b/Libraries/LibWeb/CSS/Parser/RuleParsing.cpp
@@ -198,7 +198,7 @@ GC::Ptr<CSSImportRule> Parser::convert_to_import_rule(AtRule const& rule)
         return {};
     }
 
-    return CSSImportRule::create(resolved_url.release_value(), const_cast<DOM::Document&>(*document()), supports, move(media_query_list));
+    return CSSImportRule::create(realm(), resolved_url.release_value(), const_cast<DOM::Document*>(m_document.ptr()), supports, move(media_query_list));
 }
 
 Optional<FlyString> Parser::parse_layer_name(TokenStream<ComponentValue>& tokens, AllowBlankLayerName allow_blank_layer_name)