From 54a783db1746efe4e5c8775cc7cfb69e765c2fb5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Wed, 14 Jun 2023 21:08:21 +0000
Subject: [PATCH] style: Add a way to optimize the "attribute in no namespace
 exists" check

Go through the slow path by default. No behavior change.

Differential Revision: https://phabricator.services.mozilla.com/D180528
---
 components/selectors/matching.rs |  6 +-----
 components/selectors/tree.rs     | 11 +++++++++++
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/components/selectors/matching.rs b/components/selectors/matching.rs
index f347dc4078e..6a603f10abd 100644
--- a/components/selectors/matching.rs
+++ b/components/selectors/matching.rs
@@ -730,11 +730,7 @@ where
         Component::AttributeInNoNamespaceExists {
             ref local_name,
             ref local_name_lower,
-        } => element.attr_matches(
-            &NamespaceConstraint::Specific(&crate::parser::namespace_empty_string::<E::Impl>()),
-            select_name(element, local_name, local_name_lower),
-            &AttrSelectorOperation::Exists,
-        ),
+        } => element.has_attr_in_no_namespace(select_name(element, local_name, local_name_lower)),
         Component::AttributeInNoNamespace {
             ref local_name,
             ref value,
diff --git a/components/selectors/tree.rs b/components/selectors/tree.rs
index fa150def0d6..560b1e61d81 100644
--- a/components/selectors/tree.rs
+++ b/components/selectors/tree.rs
@@ -80,6 +80,17 @@ pub trait Element: Sized + Clone + Debug {
         operation: &AttrSelectorOperation<&<Self::Impl as SelectorImpl>::AttrValue>,
     ) -> bool;
 
+    fn has_attr_in_no_namespace(
+        &self,
+        local_name: &<Self::Impl as SelectorImpl>::LocalName,
+    ) -> bool {
+        self.attr_matches(
+            &NamespaceConstraint::Specific(&crate::parser::namespace_empty_string::<Self::Impl>()),
+            local_name,
+            &AttrSelectorOperation::Exists,
+        )
+    }
+
     fn match_non_ts_pseudo_class(
         &self,
         pc: &<Self::Impl as SelectorImpl>::NonTSPseudoClass,