1 files changed, 30 insertions, 16 deletions
diff --git a/components/style/sharing/mod.rs b/components/style/sharing/mod.rs
index e99da60f4b9..d48ddc94017 100644
--- a/components/style/sharing/mod.rs
+++ b/components/style/sharing/mod.rs
@@ -206,10 +206,11 @@ impl ValidationData {
         bloom: &StyleBloom<E>,
         nth_index_cache: &mut NthIndexCache,
         bloom_known_valid: bool,
-        flags_setter: &mut F
+        flags_setter: &mut F,
     ) -> &SmallBitVec
-        where E: TElement,
-              F: FnMut(&E, ElementSelectorFlags),
+    where
+        E: TElement,
+        F: FnMut(&E, ElementSelectorFlags),
     {
         if self.revalidation_match_results.is_none() {
             // The bloom filter may already be set up for our element.
@@ -230,10 +231,12 @@ impl ValidationData {
                 }
             };
             self.revalidation_match_results =
-                Some(stylist.match_revalidation_selectors(&element,
-                                                          bloom_to_use,
-                                                          nth_index_cache,
-                                                          flags_setter));
+                Some(stylist.match_revalidation_selectors(
+                    element,
+                    bloom_to_use,
+                    nth_index_cache,
+                    flags_setter,
+                ));
         }
 
         self.revalidation_match_results.as_ref().unwrap()
@@ -661,6 +664,15 @@ impl<E: TElement> StyleSharingCache<E> {
             return None;
         }
 
+        // Note that in the XBL case, we should be able to assert that the
+        // scopes are different, since two elements with different XBL bindings
+        // need to necessarily have different style (and thus children of them
+        // would never pass the parent check).
+        if target.element.style_scope() != candidate.element.style_scope() {
+            trace!("Miss: Different style scopes");
+            return None;
+        }
+
         if *target.get_local_name() != *candidate.element.get_local_name() {
             trace!("Miss: Local Name");
             return None;
@@ -690,15 +702,17 @@ impl<E: TElement> StyleSharingCache<E> {
             return None;
         }
 
-        let element_id = target.element.get_id();
-        let candidate_id = candidate.element.get_id();
-        if element_id != candidate_id {
-            // It's possible that there are no styles for either id.
-            if checks::may_have_rules_for_ids(shared, element_id.as_ref(),
-                                              candidate_id.as_ref()) {
-                trace!("Miss: ID Attr");
-                return None;
-            }
+        // It's possible that there are no styles for either id.
+        let may_match_different_id_rules =
+            checks::may_match_different_id_rules(
+                shared,
+                target.element,
+                candidate.element,
+            );
+
+        if may_match_different_id_rules {
+            trace!("Miss: ID Attr");
+            return None;
         }
 
         if !checks::have_same_style_attribute(target, candidate) {