LibWeb: Handle some more parser inputs in the "in head" insertion mode

Libraries/LibWeb/Parser/HTMLDocumentParser.cpp

@@ -206,6 +206,23 @@ void HTMLDocumentParser::handle_in_head(HTMLToken& token)
         return;
     }
 
+    if (token.is_doctype()) {
+        PARSE_ERROR();
+        return;
+    }
+
+    if (token.is_start_tag() && token.tag_name() == "html") {
+        process_using_the_rules_for(InsertionMode::InBody, token);
+        return;
+    }
+
+    if (token.is_start_tag() && token.tag_name().is_one_of("base", "basefont", "bgsound", "link")) {
+        insert_html_element(token);
+        m_stack_of_open_elements.pop();
+        token.acknowledge_self_closing_flag_if_set();
+        return;
+    }
+
     if (token.is_start_tag() && token.tag_name() == "title") {
         insert_html_element(token);
         m_tokenizer.switch_to({}, HTMLTokenizer::State::RCDATA);
@@ -245,9 +262,7 @@ void HTMLDocumentParser::handle_in_head(HTMLToken& token)
     if (token.is_start_tag() && token.tag_name() == "meta") {
         auto element = insert_html_element(token);
         m_stack_of_open_elements.pop();
-        if (token.is_self_closing()) {
-            ASSERT_NOT_REACHED();
-        }
+        token.acknowledge_self_closing_flag_if_set();
         return;
     }
     if (token.is_end_tag() && token.tag_name() == "head") {

Libraries/LibWeb/Parser/HTMLToken.h

@@ -92,6 +92,18 @@ public:
         return m_tag.self_closing;
     }
 
+    bool has_acknowledged_self_closing_flag() const
+    {
+        ASSERT(is_self_closing());
+        return m_tag.self_closing_acknowledged;
+    }
+
+    void acknowledge_self_closing_flag_if_set()
+    {
+        if (is_self_closing())
+            m_tag.self_closing_acknowledged = true;
+    }
+
     Type type() const { return m_type; }
 
     String to_string() const;
@@ -117,6 +129,7 @@ private:
     struct {
         StringBuilder tag_name;
         bool self_closing { false };
+        bool self_closing_acknowledged { false };
         Vector<AttributeBuilder> attributes;
     } m_tag;