selectors: Never match ::slotted on <slot>s.

This fixes the test from https://github.com/w3c/web-platform-tests/pull/9212 in
Gecko.

1 files changed, 11 insertions, 0 deletions

diff --git a/components/layout_thread/dom_wrapper.rs b/components/layout_thread/dom_wrapper.rs
index 0110704edad..a909ce72e8f 100644
--- a/components/layout_thread/dom_wrapper.rs
+++ b/components/layout_thread/dom_wrapper.rs
@@ -784,6 +784,13 @@ impl<'le> ::selectors::Element for ServoLayoutElement<'le> {
         }
     }
 
+    fn is_html_slot_element(&self) -> bool {
+        unsafe {
+            self.element.is_html_element() &&
+            self.get_local_name() == &local_name!("slot")
+        }
+    }
+
     fn is_html_element_in_html_document(&self) -> bool {
         unsafe {
             if !self.element.is_html_element() {
@@ -1176,6 +1183,10 @@ impl<'le> ::selectors::Element for ServoThreadSafeLayoutElement<'le> {
         None
     }
 
+    fn is_html_slot_element(&self) -> bool {
+        self.element.is_html_slot_element()
+    }
+
     fn is_html_element_in_html_document(&self) -> bool {
         debug!("ServoThreadSafeLayoutElement::is_html_element_in_html_document called");
         true