1 files changed, 14 insertions, 5 deletions
diff --git a/components/style/sequential.rs b/components/style/sequential.rs
index a5a9b519e57..56b8a563d27 100644
--- a/components/style/sequential.rs
+++ b/components/style/sequential.rs
@@ -9,20 +9,29 @@ use traversal::DomTraversalContext;
 
 pub fn traverse_dom<N, C>(root: N,
                           shared: &C::SharedContext)
-                          where N: TNode,
-                                C: DomTraversalContext<N> {
+    where N: TNode,
+          C: DomTraversalContext<N>
+{
     fn doit<'a, N, C>(context: &'a C, node: N)
-                      where N: TNode, C: DomTraversalContext<N> {
+        where N: TNode,
+              C: DomTraversalContext<N>
+    {
+        debug_assert!(context.should_process(node));
         context.process_preorder(node);
 
         for kid in node.children() {
-            doit::<N, C>(context, kid);
+            context.pre_process_child_hook(node, kid);
+            if context.should_process(node) {
+                doit::<N, C>(context, kid);
+            }
         }
 
         context.process_postorder(node);
     }
 
     let context = C::new(shared, root.opaque());
-    doit::<N, C>(&context, root);
+    if context.should_process(root) {
+        doit::<N, C>(&context, root);
+    }
 }