From 4b9c5635b36df645c83e9e2f1da269794717cbb1 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Wed, 14 Sep 2022 13:29:07 +0200
Subject: [PATCH] LibWeb: Make :link selector behave according to spec

It should match any `a` or `area` element that has an `href` attribute,
not any element *inside* an enclosing linked element.
---
 Userland/Libraries/LibWeb/CSS/SelectorEngine.cpp | 13 ++++++++++++-
 Userland/Libraries/LibWeb/DOM/Node.cpp           |  5 -----
 Userland/Libraries/LibWeb/DOM/Node.h             |  2 --
 3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/Userland/Libraries/LibWeb/CSS/SelectorEngine.cpp b/Userland/Libraries/LibWeb/CSS/SelectorEngine.cpp
index f2d0586af7..dfdf426bf8 100644
--- a/Userland/Libraries/LibWeb/CSS/SelectorEngine.cpp
+++ b/Userland/Libraries/LibWeb/CSS/SelectorEngine.cpp
@@ -11,6 +11,8 @@
 #include <LibWeb/DOM/Element.h>
 #include <LibWeb/DOM/Text.h>
 #include <LibWeb/HTML/AttributeNames.h>
+#include <LibWeb/HTML/HTMLAnchorElement.h>
+#include <LibWeb/HTML/HTMLAreaElement.h>
 #include <LibWeb/HTML/HTMLHtmlElement.h>
 #include <LibWeb/HTML/HTMLInputElement.h>
 
@@ -44,6 +46,15 @@ static inline bool matches_lang_pseudo_class(DOM::Element const& element, Vector
     return false;
 }
 
+// https://html.spec.whatwg.org/multipage/semantics-other.html#selector-link
+static inline bool matches_link_pseudo_class(DOM::Element const& element)
+{
+    // All a elements that have an href attribute, and all area elements that have an href attribute, must match one of :link and :visited.
+    if (!is<HTML::HTMLAnchorElement>(element) && !is<HTML::HTMLAreaElement>(element))
+        return false;
+    return element.has_attribute(HTML::AttributeNames::href);
+}
+
 static inline bool matches_hover_pseudo_class(DOM::Element const& element)
 {
     auto* hovered_node = element.document().hovered_node();
@@ -163,7 +174,7 @@ static inline bool matches_pseudo_class(CSS::Selector::SimpleSelector::PseudoCla
 {
     switch (pseudo_class.type) {
     case CSS::Selector::SimpleSelector::PseudoClass::Type::Link:
-        return element.is_link();
+        return matches_link_pseudo_class(element);
     case CSS::Selector::SimpleSelector::PseudoClass::Type::Visited:
         // FIXME: Maybe match this selector sometimes?
         return false;
diff --git a/Userland/Libraries/LibWeb/DOM/Node.cpp b/Userland/Libraries/LibWeb/DOM/Node.cpp
index c68efd6e21..66fe1a0f6f 100644
--- a/Userland/Libraries/LibWeb/DOM/Node.cpp
+++ b/Userland/Libraries/LibWeb/DOM/Node.cpp
@@ -244,11 +244,6 @@ void Node::invalidate_style()
     document().schedule_style_update();
 }
 
-bool Node::is_link() const
-{
-    return enclosing_link_element();
-}
-
 String Node::child_text_content() const
 {
     if (!is<ParentNode>(*this))
diff --git a/Userland/Libraries/LibWeb/DOM/Node.h b/Userland/Libraries/LibWeb/DOM/Node.h
index 9f4383afb3..dcc1088192 100644
--- a/Userland/Libraries/LibWeb/DOM/Node.h
+++ b/Userland/Libraries/LibWeb/DOM/Node.h
@@ -170,8 +170,6 @@ public:
 
     void invalidate_style();
 
-    bool is_link() const;
-
     void set_document(Badge<Document>, Document&);
 
     virtual EventTarget* get_parent(Event const&) override;