Revert "LibWeb: Set doctype node immediately while parsing XML document"

This reverts commit cd446e5.

This broke about 20k WPT subtests, all related to XML parsing. See:
https://wpt.fyi/results/html/the-xhtml-syntax/parsing-xhtml-documents?diff=&filter=ADC&run_id=5154815472828416&run_id=5090731742199808

Libraries/LibWeb/XML/XMLDocumentBuilder.cpp

@@ -62,7 +62,7 @@ void XMLDocumentBuilder::set_source(ByteString source)
     m_document->set_source(MUST(String::from_byte_string(source)));
 }
 
-void XMLDocumentBuilder::doctype(XML::Doctype const& doctype)
+void XMLDocumentBuilder::set_doctype(XML::Doctype doctype)
 {
     if (m_document->doctype()) {
         return;
@@ -73,13 +73,13 @@ void XMLDocumentBuilder::doctype(XML::Doctype const& doctype)
     document_type->set_name(name);
 
     if (doctype.external_id.has_value()) {
-        auto const& external_id = *doctype.external_id;
+        auto external_id = doctype.external_id.release_value();
 
         auto system_id = MUST(AK::String::from_byte_string(external_id.system_id.system_literal));
         document_type->set_system_id(system_id);
 
         if (external_id.public_id.has_value()) {
-            auto public_id = MUST(AK::String::from_byte_string(external_id.public_id->public_literal));
+            auto public_id = MUST(AK::String::from_byte_string(external_id.public_id.release_value().public_literal));
             document_type->set_public_id(public_id);
         }
     }

Libraries/LibWeb/XML/XMLDocumentBuilder.h

@@ -31,7 +31,7 @@ class XMLDocumentBuilder final : public XML::Listener {
 
 private:
     virtual void set_source(ByteString) override;
-    virtual void doctype(XML::Doctype const&) override;
+    virtual void set_doctype(XML::Doctype) override;
     virtual void element_start(XML::Name const& name, HashMap<XML::Name, ByteString> const& attributes) override;
     virtual void element_end(XML::Name const& name) override;
     virtual void text(StringView data) override;

Libraries/LibXML/Parser/Parser.cpp

@@ -182,6 +182,9 @@ ErrorOr<void, ParseError> Parser::parse_with_listener(Listener& listener)
     if (result.is_error())
         m_listener->error(result.error());
     m_listener->document_end();
+    if (m_doctype.has_value()) {
+        m_listener->set_doctype(m_doctype.release_value());
+    }
     m_root_node.clear();
     return result;
 }
@@ -618,8 +621,7 @@ ErrorOr<void, ParseError> Parser::parse_doctype_decl()
     TRY(expect(">"sv));
 
     rollback.disarm();
-    if (m_listener)
-        m_listener->doctype(doctype);
+    m_doctype = move(doctype);
     return {};
 }
 

Libraries/LibXML/Parser/Parser.h

@@ -34,9 +34,9 @@ struct Listener {
     virtual ~Listener() { }
 
     virtual void set_source(ByteString) { }
+    virtual void set_doctype(XML::Doctype) { }
     virtual void document_start() { }
     virtual void document_end() { }
-    virtual void doctype(Doctype const&) { }
     virtual void element_start(Name const&, HashMap<Name, ByteString> const&) { }
     virtual void element_end(Name const&) { }
     virtual void text(StringView) { }