Auto merge of #5645 - nox:treeiterator-temporary, r=Ms2ger

10 files changed, 172 insertions, 147 deletions

diff --git a/components/script/devtools.rs b/components/script/devtools.rs
index 56588941667..8b9bb84e830 100644
--- a/components/script/devtools.rs
+++ b/components/script/devtools.rs
@@ -69,8 +69,8 @@ fn find_node_by_unique_id(page: &Rc<Page>, pipeline: PipelineId, node_id: String
     let node: JSRef<Node> = NodeCast::from_ref(document.r());
 
     for candidate in node.traverse_preorder() {
-        if candidate.get_unique_id() == node_id {
-            return Temporary::from_rooted(candidate);
+        if candidate.root().r().get_unique_id() == node_id {
+            return candidate;
         }
     }
 
diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index 57cee418838..f001f0268f3 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -26,6 +26,7 @@ use dom::bindings::global::GlobalRef;
 use dom::bindings::js::{MutNullableJS, JS, JSRef, LayoutJS, Temporary, TemporaryPushable};
 use dom::bindings::js::{OptionalRootable, RootedReference};
 use dom::bindings::refcounted::Trusted;
+use dom::bindings::trace::RootedVec;
 use dom::bindings::utils::reflect_dom_object;
 use dom::bindings::utils::{xml_name_type, validate_and_extract};
 use dom::bindings::utils::XMLName::InvalidXMLName;
@@ -343,12 +344,12 @@ impl<'a> DocumentHelpers<'a> for JSRef<'a, Document> {
                 let mut head: usize = 0;
                 let root: JSRef<Node> = NodeCast::from_ref(root.r());
                 for node in root.traverse_preorder() {
-                    let elem: Option<JSRef<Element>> = ElementCast::to_ref(node);
-                    if let Some(elem) = elem {
+                    let node = node.root();
+                    if let Some(elem) = ElementCast::to_ref(node.r()) {
                         if (*elements)[head].root().r() == elem {
                             head += 1;
                         }
-                        if new_node == node || head == elements.len() {
+                        if new_node == node.r() || head == elements.len() {
                             break;
                         }
                     }
@@ -379,9 +380,9 @@ impl<'a> DocumentHelpers<'a> for JSRef<'a, Document> {
             };
             let doc_node: JSRef<Node> = NodeCast::from_ref(self);
             doc_node.traverse_preorder()
-                    .filter_map(HTMLAnchorElementCast::to_ref)
-                    .find(check_anchor)
-                    .map(|node| Temporary::from_rooted(ElementCast::from_ref(node)))
+                    .filter_map(HTMLAnchorElementCast::to_temporary)
+                    .find(|node| check_anchor(&node.root().r()))
+                    .map(ElementCast::from_temporary)
         })
     }
 
@@ -493,7 +494,7 @@ impl<'a> DocumentHelpers<'a> for JSRef<'a, Document> {
     fn dirty_all_nodes(self) {
         let root: JSRef<Node> = NodeCast::from_ref(self);
         for node in root.traverse_preorder() {
-            node.dirty(NodeDamage::OtherNodeDamage)
+            node.root().r().dirty(NodeDamage::OtherNodeDamage)
         }
     }
 
@@ -817,22 +818,24 @@ impl Document {
 }
 
 trait PrivateDocumentHelpers {
-    fn createNodeList<F: Fn(JSRef<Node>) -> bool>(self, callback: F) -> Temporary<NodeList>;
+    fn create_node_list<F: Fn(JSRef<Node>) -> bool>(self, callback: F) -> Temporary<NodeList>;
     fn get_html_element(self) -> Option<Temporary<HTMLHtmlElement>>;
 }
 
 impl<'a> PrivateDocumentHelpers for JSRef<'a, Document> {
-    fn createNodeList<F: Fn(JSRef<Node>) -> bool>(self, callback: F) -> Temporary<NodeList> {
+    fn create_node_list<F: Fn(JSRef<Node>) -> bool>(self, callback: F) -> Temporary<NodeList> {
         let window = self.window.root();
         let document_element = self.GetDocumentElement().root();
-        let nodes = match document_element {
-            None => vec!(),
-            Some(ref root) => {
-                let root: JSRef<Node> = NodeCast::from_ref(root.r());
-                root.traverse_preorder().filter(|&node| callback(node)).collect()
+        let mut nodes = RootedVec::new();
+        if let Some(ref root) = document_element {
+            for node in NodeCast::from_ref(root.r()).traverse_preorder() {
+                let node = node.root();
+                if callback(node.r()) {
+                    nodes.push(node.r().unrooted());
+                }
             }
         };
-        NodeList::new_simple_list(window.r(), nodes)
+        NodeList::new_simple_list(window.r(), &nodes)
     }
 
     fn get_html_element(self) -> Option<Temporary<HTMLHtmlElement>> {
@@ -1118,14 +1121,14 @@ impl<'a> DocumentMethods for JSRef<'a, Document> {
     // http://www.whatwg.org/specs/web-apps/current-work/#document.title
     fn Title(self) -> DOMString {
         let title_element = self.GetDocumentElement().root().and_then(|root| {
-            NodeCast::from_ref(root.get_unsound_ref_forever())
-                .traverse_preorder()
-                .find(|node| node.type_id() == NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLTitleElement)))
-        });
+            NodeCast::from_ref(root.r()).traverse_preorder().find(|node| {
+                node.root().r().type_id() == NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLTitleElement))
+            })
+        }).root();
 
         let mut title = String::new();
         if let Some(title_element) = title_element {
-            for child in title_element.children() {
+            for child in title_element.r().children() {
                 let child = child.root();
                 if let Some(text) = TextCast::to_ref(child.r()) {
                     title.push_str(&CharacterDataCast::from_ref(text).data());
@@ -1142,9 +1145,9 @@ impl<'a> DocumentMethods for JSRef<'a, Document> {
         self.GetDocumentElement().root().map(|root| {
             let root: JSRef<Node> = NodeCast::from_ref(root.r());
             let head_node = root.traverse_preorder().find(|child| {
-                child.type_id() == NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLHeadElement))
-            });
-            head_node.map(|head| {
+                child.root().r().type_id() == NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLHeadElement))
+            }).root();
+            head_node.r().map(|head| {
                 let title_node = head.children().map(|c| c.root()).find(|child| {
                     child.r().type_id() == NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLTitleElement))
                 });
@@ -1255,7 +1258,7 @@ impl<'a> DocumentMethods for JSRef<'a, Document> {
 
     // http://www.whatwg.org/specs/web-apps/current-work/#dom-document-getelementsbyname
     fn GetElementsByName(self, name: DOMString) -> Temporary<NodeList> {
-        self.createNodeList(|node| {
+        self.create_node_list(|node| {
             let element: JSRef<Element> = match ElementCast::to_ref(node) {
                 Some(element) => element,
                 None => return false,
diff --git a/components/script/dom/htmlbuttonelement.rs b/components/script/dom/htmlbuttonelement.rs
index aaf725d1d9e..a4877e72aa4 100644
--- a/components/script/dom/htmlbuttonelement.rs
+++ b/components/script/dom/htmlbuttonelement.rs
@@ -224,12 +224,10 @@ impl<'a> Activatable for JSRef<'a, HTMLButtonElement> {
         // and only then performing actions which may modify the DOM tree
         unsafe {
             node.query_selector_iter("button[type=submit]".to_owned()).unwrap()
-                .filter_map(|t| {
-                    let h: Option<JSRef<HTMLButtonElement>> = HTMLButtonElementCast::to_ref(t);
-                    h
-                })
-                .find(|r| r.form_owner() == owner)
-                .map(|s| s.synthetic_click_activation(ctrlKey, shiftKey, altKey, metaKey));
+                .filter_map(HTMLButtonElementCast::to_temporary)
+                .map(|t| t.root())
+                .find(|r| r.r().form_owner() == owner)
+                .map(|s| s.r().synthetic_click_activation(ctrlKey, shiftKey, altKey, metaKey));
         }
     }
 }
diff --git a/components/script/dom/htmlcollection.rs b/components/script/dom/htmlcollection.rs
index a6e216cffdb..a2cf605bc7e 100644
--- a/components/script/dom/htmlcollection.rs
+++ b/components/script/dom/htmlcollection.rs
@@ -164,12 +164,13 @@ impl HTMLCollection {
         HTMLCollection::create(window, root, box ElementChildFilter)
     }
 
-    fn traverse<'a>(root: JSRef<'a, Node>)
-                    -> FilterMap<Skip<TreeIterator<'a>>,
-                                 fn(JSRef<Node>) -> Option<JSRef<Element>>> {
+    fn traverse(root: JSRef<Node>)
+                -> FilterMap<Skip<TreeIterator>,
+                             fn(Temporary<Node>) -> Option<Temporary<Element>>> {
         root.traverse_preorder()
             .skip(1)
-            .filter_map(ElementCast::to_ref as fn(JSRef<Node>) -> Option<JSRef<Element>>)
+            .filter_map(ElementCast::to_temporary as
+                        fn(Temporary<Node>) -> Option<Temporary<Element>>)
     }
 }
 
@@ -181,7 +182,7 @@ impl<'a> HTMLCollectionMethods for JSRef<'a, HTMLCollection> {
             CollectionTypeId::Live(ref root, ref filter) => {
                 let root = root.root();
                 HTMLCollection::traverse(root.r())
-                    .filter(|element| filter.filter(*element, root.r()))
+                    .filter(|element| filter.filter(element.root().r(), root.r()))
                     .count() as u32
             }
         }
@@ -198,10 +199,8 @@ impl<'a> HTMLCollectionMethods for JSRef<'a, HTMLCollection> {
             CollectionTypeId::Live(ref root, ref filter) => {
                 let root = root.root();
                 HTMLCollection::traverse(root.r())
-                    .filter(|element| filter.filter(*element, root.r()))
+                    .filter(|element| filter.filter(element.root().r(), root.r()))
                     .nth(index)
-                    .clone()
-                    .map(Temporary::from_rooted)
             }
         }
     }
@@ -224,11 +223,12 @@ impl<'a> HTMLCollectionMethods for JSRef<'a, HTMLCollection> {
             CollectionTypeId::Live(ref root, ref filter) => {
                 let root = root.root();
                 HTMLCollection::traverse(root.r())
-                    .filter(|element| filter.filter(*element, root.r()))
+                    .map(|element| element.root())
+                    .filter(|element| filter.filter(element.r(), root.r()))
                     .find(|elem| {
-                        elem.get_string_attribute(&atom!("name")) == key ||
-                        elem.get_string_attribute(&atom!("id")) == key })
-                    .map(Temporary::from_rooted)
+                        elem.r().get_string_attribute(&atom!("name")) == key ||
+                        elem.r().get_string_attribute(&atom!("id")) == key })
+                    .map(|elem| Temporary::from_rooted(elem.r()))
             }
         }
     }
diff --git a/components/script/dom/htmlfieldsetelement.rs b/components/script/dom/htmlfieldsetelement.rs
index 39088810eab..e3b8397e4bc 100644
--- a/components/script/dom/htmlfieldsetelement.rs
+++ b/components/script/dom/htmlfieldsetelement.rs
@@ -104,13 +104,14 @@ impl<'a> VirtualMethods for JSRef<'a, HTMLFieldSetElement> {
                     }
 
                     for descendant in child.r().traverse_preorder() {
-                        match descendant.type_id() {
+                        let descendant = descendant.root();
+                        match descendant.r().type_id() {
                             NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLButtonElement)) |
                             NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLInputElement)) |
                             NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLSelectElement)) |
                             NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLTextAreaElement)) => {
-                                descendant.set_disabled_state(true);
-                                descendant.set_enabled_state(false);
+                                descendant.r().set_disabled_state(true);
+                                descendant.r().set_enabled_state(false);
                             },
                             _ => ()
                         }
@@ -142,13 +143,14 @@ impl<'a> VirtualMethods for JSRef<'a, HTMLFieldSetElement> {
                     }
 
                     for descendant in child.r().traverse_preorder() {
-                        match descendant.type_id() {
+                        let descendant = descendant.root();
+                        match descendant.r().type_id() {
                             NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLButtonElement)) |
                             NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLInputElement)) |
                             NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLSelectElement)) |
                             NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLTextAreaElement)) => {
-                                descendant.check_disabled_attribute();
-                                descendant.check_ancestors_disabled_state_for_form_control();
+                                descendant.r().check_disabled_attribute();
+                                descendant.r().check_ancestors_disabled_state_for_form_control();
                             },
                             _ => ()
                         }
diff --git a/components/script/dom/htmlformelement.rs b/components/script/dom/htmlformelement.rs
index 395a9ab8522..7bd9925ffd2 100644
--- a/components/script/dom/htmlformelement.rs
+++ b/components/script/dom/htmlformelement.rs
@@ -20,7 +20,7 @@ use dom::element::ElementTypeId;
 use dom::htmlelement::{HTMLElement, HTMLElementTypeId};
 use dom::htmlinputelement::{HTMLInputElement, HTMLInputElementHelpers};
 use dom::htmlbuttonelement::{HTMLButtonElement};
-use dom::htmltextareaelement::{HTMLTextAreaElement, HTMLTextAreaElementHelpers};
+use dom::htmltextareaelement::HTMLTextAreaElementHelpers;
 use dom::node::{Node, NodeHelpers, NodeTypeId, document_from_node, window_from_node};
 use hyper::method::Method;
 use hyper::header::ContentType;
@@ -255,16 +255,18 @@ impl<'a> HTMLFormElementHelpers for JSRef<'a, HTMLFormElement> {
         // TODO: This is an incorrect way of getting controls owned
         //       by the form, but good enough until html5ever lands
         let data_set = node.traverse_preorder().filter_map(|child| {
-            if child.get_disabled_state() {
+            let child = child.root();
+            if child.r().get_disabled_state() {
                 return None;
             }
-            if child.ancestors().any(|a| a.root().r().type_id() == NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLDataListElement))) {
+            if child.r().ancestors()
+                        .any(|a| a.root().r().type_id() == NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLDataListElement))) {
                 return None;
             }
             // XXXManishearth don't include it if it is a button but not the submitter
-            match child.type_id() {
+            match child.r().type_id() {
                 NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLInputElement)) => {
-                    let input: JSRef<HTMLInputElement> = HTMLInputElementCast::to_ref(child).unwrap();
+                    let input = HTMLInputElementCast::to_ref(child.r()).unwrap();
                     let ty = input.Type();
                     let name = input.Name();
                     match ty.as_slice() {
@@ -368,10 +370,10 @@ impl<'a> HTMLFormElementHelpers for JSRef<'a, HTMLFormElement> {
         // TODO: This is an incorrect way of getting controls owned
         //       by the form, but good enough until html5ever lands
         for child in node.traverse_preorder() {
-            match child.type_id() {
+            let child = child.root();
+            match child.r().type_id() {
                 NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLInputElement)) => {
-                    let input: JSRef<HTMLInputElement> = HTMLInputElementCast::to_ref(child)
-                                                                               .unwrap();
+                    let input = HTMLInputElementCast::to_ref(child.r()).unwrap();
                     input.reset()
                 }
                 // TODO HTMLKeygenElement unimplemented
@@ -384,8 +386,7 @@ impl<'a> HTMLFormElementHelpers for JSRef<'a, HTMLFormElement> {
                     {}
                 }
                 NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLTextAreaElement)) => {
-                    let textarea: JSRef<HTMLTextAreaElement> = HTMLTextAreaElementCast::to_ref(child)
-                                                                                        .unwrap();
+                    let textarea = HTMLTextAreaElementCast::to_ref(child.r()).unwrap();
                     textarea.reset()
                 }
                 NodeTypeId::Element(ElementTypeId::HTMLElement(HTMLElementTypeId::HTMLOutputElement)) => {
diff --git a/components/script/dom/htmlinputelement.rs b/components/script/dom/htmlinputelement.rs
index cb3eff8c59b..30cd0676eb1 100644
--- a/components/script/dom/htmlinputelement.rs
+++ b/components/script/dom/htmlinputelement.rs
@@ -346,12 +346,13 @@ fn broadcast_radio_checked(broadcaster: JSRef<HTMLInputElement>, group: Option<&
         // There is no DOM tree manipulation here, so this is safe
         let iter = unsafe {
             doc_node.query_selector_iter("input[type=radio]".to_owned()).unwrap()
-                .filter_map(|t| HTMLInputElementCast::to_ref(t))
-                .filter(|&r| in_same_group(r, owner, group) && broadcaster != r)
+                .filter_map(HTMLInputElementCast::to_temporary)
+                .map(|t| t.root())
+                .filter(|r| in_same_group(r.r(), owner, group) && broadcaster != r.r())
         };
         for r in iter {
-            if r.Checked() {
-                r.SetChecked(false);
+            if r.r().Checked() {
+                r.r().SetChecked(false);
             }
         }
     }
@@ -684,12 +685,14 @@ impl<'a> Activatable for JSRef<'a, HTMLInputElement> {
                     // Safe since we only manipulate the DOM tree after finding an element
                     let checked_member = unsafe {
                         doc_node.query_selector_iter("input[type=radio]".to_owned()).unwrap()
-                                .filter_map(|t| HTMLInputElementCast::to_ref(t))
-                                .filter(|&r| in_same_group(r, owner.r(),
-                                                           group.as_ref().map(|gr| gr.as_slice())))
-                                .find(|r| r.Checked())
+                                .filter_map(HTMLInputElementCast::to_temporary)
+                                .map(|t| t.root())
+                                .find(|r| {
+                                    in_same_group(r.r(), owner.r(), group.as_ref().map(|gr| gr.as_slice())) &&
+                                    r.r().Checked()
+                                })
                     };
-                    cache.checked_radio.assign(checked_member);
+                    cache.checked_radio.assign(checked_member.r());
                     cache.checked_changed = self.checked_changed.get();
                     self.SetChecked(true);
                 }
@@ -815,12 +818,10 @@ impl<'a> Activatable for JSRef<'a, HTMLInputElement> {
         // and only then performing actions which may modify the DOM tree
         unsafe {
             node.query_selector_iter("input[type=submit]".to_owned()).unwrap()
-                .filter_map(|t| {
-                    let h: Option<JSRef<HTMLInputElement>> = HTMLInputElementCast::to_ref(t);
-                    h
-                })
-                .find(|r| r.form_owner() == owner)
-                .map(|s| s.synthetic_click_activation(ctrlKey, shiftKey, altKey, metaKey));
+                .filter_map(HTMLInputElementCast::to_temporary)
+                .map(|t| t.root())
+                .find(|r| r.r().form_owner() == owner)
+                .map(|s| s.r().synthetic_click_activation(ctrlKey, shiftKey, altKey, metaKey));
         }
     }
 }
diff --git a/components/script/dom/node.rs b/components/script/dom/node.rs
index e628ee4b2d9..6e96e560101 100644
--- a/components/script/dom/node.rs
+++ b/components/script/dom/node.rs
@@ -290,7 +290,8 @@ impl<'a> PrivateNodeHelpers for JSRef<'a, Node> {
         let is_in_doc = self.is_in_doc();
 
         for node in self.traverse_preorder() {
-            vtable_for(&node).bind_to_tree(is_in_doc);
+            let node = node.root();
+            vtable_for(&node.r()).bind_to_tree(is_in_doc);
         }
 
         let parent = self.parent_node().root();
@@ -302,7 +303,8 @@ impl<'a> PrivateNodeHelpers for JSRef<'a, Node> {
     fn node_removed(self, parent_in_doc: bool) {
         assert!(self.parent_node().is_none());
         for node in self.traverse_preorder() {
-            vtable_for(&node).unbind_from_tree(parent_in_doc);
+            let node = node.root();
+            vtable_for(&node.r()).unbind_from_tree(parent_in_doc);
         }
         self.layout_data.dispose();
     }
@@ -381,14 +383,15 @@ impl<'a> PrivateNodeHelpers for JSRef<'a, Node> {
     }
 }
 
-pub struct QuerySelectorIterator<'a> {
+pub struct QuerySelectorIterator {
     selectors: Vec<Selector>,
-    iterator: TreeIterator<'a>,
+    iterator: TreeIterator,
 }
 
-impl<'a> QuerySelectorIterator<'a> {
+impl<'a> QuerySelectorIterator {
     #[allow(unsafe_code)]
-    unsafe fn new(iter: TreeIterator<'a>, selectors: Vec<Selector>) -> QuerySelectorIterator<'a> {
+    unsafe fn new(iter: TreeIterator, selectors: Vec<Selector>)
+                  -> QuerySelectorIterator {
         QuerySelectorIterator {
             selectors: selectors,
             iterator: iter,
@@ -396,18 +399,21 @@ impl<'a> QuerySelectorIterator<'a> {
     }
 }
 
-impl<'a> Iterator for QuerySelectorIterator<'a> {
-    type Item = JSRef<'a, Node>;
+impl<'a> Iterator for QuerySelectorIterator {
+    type Item = Temporary<Node>;
 
-    fn next(&mut self) -> Option<JSRef<'a, Node>> {
+    fn next(&mut self) -> Option<Temporary<Node>> {
         let selectors = &self.selectors;
         // TODO(cgaebel): Is it worth it to build a bloom filter here
         // (instead of passing `None`)? Probably.
-        self.iterator.find(|node| node.is_element() && matches(selectors, node, &mut None))
+        self.iterator.find(|node| {
+            let node = node.root();
+            node.r().is_element() && matches(selectors, &node.r(), &mut None)
+        })
     }
 }
 
-pub trait NodeHelpers<'a> {
+pub trait NodeHelpers {
     fn ancestors(self) -> AncestorIterator;
     fn inclusive_ancestors(self) -> AncestorIterator;
     fn children(self) -> NodeSiblingIterator;
@@ -484,7 +490,7 @@ pub trait NodeHelpers<'a> {
     fn dump_indent(self, indent: u32);
     fn debug_str(self) -> String;
 
-    fn traverse_preorder(self) -> TreeIterator<'a>;
+    fn traverse_preorder(self) -> TreeIterator;
     fn inclusively_following_siblings(self) -> NodeSiblingIterator;
     fn inclusively_preceding_siblings(self) -> ReverseSiblingIterator;
 
@@ -495,7 +501,7 @@ pub trait NodeHelpers<'a> {
 
     fn query_selector(self, selectors: DOMString) -> Fallible<Option<Temporary<Element>>>;
     #[allow(unsafe_code)]
-    unsafe fn query_selector_iter(self, selectors: DOMString) -> Fallible<QuerySelectorIterator<'a>>;
+    unsafe fn query_selector_iter(self, selectors: DOMString) -> Fallible<QuerySelectorIterator>;
     fn query_selector_all(self, selectors: DOMString) -> Fallible<Temporary<NodeList>>;
 
     fn remove_self(self);
@@ -508,7 +514,7 @@ pub trait NodeHelpers<'a> {
     fn parse_fragment(self, markup: DOMString) -> Fallible<Temporary<DocumentFragment>>;
 }
 
-impl<'a> NodeHelpers<'a> for JSRef<'a, Node> {
+impl<'a> NodeHelpers for JSRef<'a, Node> {
     fn teardown(self) {
         self.layout_data.dispose();
         for kid in self.children() {
@@ -745,7 +751,7 @@ impl<'a> NodeHelpers<'a> for JSRef<'a, Node> {
     }
 
     /// Iterates over this node and all its descendants, in preorder.
-    fn traverse_preorder(self) -> TreeIterator<'a> {
+    fn traverse_preorder(self) -> TreeIterator {
         TreeIterator::new(self)
     }
 
@@ -806,10 +812,9 @@ impl<'a> NodeHelpers<'a> for JSRef<'a, Node> {
             Ok(ref selectors) => {
                 let root = self.ancestors().last().root();
                 let root = root.r().unwrap_or(self.clone());
-                Ok(root.traverse_preorder()
-                       .filter_map(ElementCast::to_ref)
-                       .find(|element| matches(selectors, &NodeCast::from_ref(*element), &mut None))
-                       .map(Temporary::from_rooted))
+                Ok(root.traverse_preorder().filter_map(ElementCast::to_temporary).find(|element| {
+                    matches(selectors, &NodeCast::from_ref(element.root().r()), &mut None)
+                }))
             }
         }
     }
@@ -819,7 +824,7 @@ impl<'a> NodeHelpers<'a> for JSRef<'a, Node> {
     /// the iterator may be invalidated
     #[allow(unsafe_code)]
     unsafe fn query_selector_iter(self, selectors: DOMString)
-                                  -> Fallible<QuerySelectorIterator<'a>> {
+                                  -> Fallible<QuerySelectorIterator> {
         // Step 1.
         let nodes;
         let root = self.ancestors().last().root()
@@ -839,13 +844,12 @@ impl<'a> NodeHelpers<'a> for JSRef<'a, Node> {
     // http://dom.spec.whatwg.org/#dom-parentnode-queryselectorall
     #[allow(unsafe_code)]
     fn query_selector_all(self, selectors: DOMString) -> Fallible<Temporary<NodeList>> {
-        // Step 1.
-        unsafe {
-            self.query_selector_iter(selectors).map(|iter| {
-                let window = window_from_node(self).root();
-                NodeList::new_simple_list(window.r(), iter.collect())
-            })
+        let mut nodes = RootedVec::new();
+        for node in try!(unsafe { self.query_selector_iter(selectors) }) {
+            nodes.push(JS::from_rooted(node));
         }
+        let window = window_from_node(self).root();
+        Ok(NodeList::new_simple_list(window.r(), &nodes))
     }
 
 
@@ -1179,30 +1183,48 @@ impl Iterator for AncestorIterator {
     }
 }
 
-pub struct TreeIterator<'a> {
-    stack: Vec<JSRef<'a, Node>>,
+pub struct TreeIterator {
+    current: Option<Temporary<Node>>,
+    depth: usize,
 }
 
-impl<'a> TreeIterator<'a> {
-    fn new(root: JSRef<'a, Node>) -> TreeIterator<'a> {
-        let mut stack = vec!();
-        stack.push(root);
-
+impl<'a> TreeIterator {
+    fn new(root: JSRef<'a, Node>) -> TreeIterator {
         TreeIterator {
-            stack: stack,
+            current: Some(Temporary::from_rooted(root)),
+            depth: 0,
         }
     }
 }
 
-impl<'a> Iterator for TreeIterator<'a> {
-    type Item = JSRef<'a, Node>;
+impl Iterator for TreeIterator {
+    type Item = Temporary<Node>;
 
-    fn next(&mut self) -> Option<JSRef<'a, Node>> {
-        let ret = self.stack.pop();
-        ret.map(|node| {
-            self.stack.extend(node.rev_children().map(|c| c.root().get_unsound_ref_forever()))
-        });
-        ret
+    // https://dom.spec.whatwg.org/#concept-tree-order
+    fn next(&mut self) -> Option<Temporary<Node>> {
+        let current = match self.current.take() {
+            None => return None,
+            Some(current) => current,
+        };
+        let node = current.root();
+        if let Some(first_child) = node.r().first_child() {
+            self.current = Some(first_child);
+            self.depth += 1;
+            return Some(current);
+        };
+        for ancestor in node.r().inclusive_ancestors() {
+            if self.depth == 0 {
+                break;
+            }
+            if let Some(next_sibling) = ancestor.root().r().next_sibling() {
+                self.current = Some(next_sibling);
+                return Some(current);
+            }
+            self.depth -= 1;
+        }
+        debug_assert!(self.depth == 0);
+        self.current = None;
+        Some(current)
     }
 }
 
@@ -1284,7 +1306,7 @@ impl Node {
         let node_doc = document_from_node(node).root();
         if node_doc.r() != document {
             for descendant in node.traverse_preorder() {
-                descendant.set_owner_doc(document);
+                descendant.root().r().set_owner_doc(document);
             }
         }
 
@@ -1439,13 +1461,14 @@ impl Node {
             parent.add_child(node, child);
             let is_in_doc = parent.is_in_doc();
             for kid in node.traverse_preorder() {
-                let mut flags = kid.flags.get();
+                let kid = kid.root();
+                let mut flags = kid.r().flags.get();
                 if is_in_doc {
                     flags.insert(IS_IN_DOC);
                 } else {
                     flags.remove(IS_IN_DOC);
                 }
-                kid.flags.set(flags);
+                kid.r().flags.set(flags);
             }
         }
 
@@ -1848,8 +1871,7 @@ impl<'a> NodeMethods for JSRef<'a, Node> {
         match self.type_id {
             NodeTypeId::DocumentFragment |
             NodeTypeId::Element(..) => {
-                let content = Node::collect_text_contents(
-                    self.traverse_preorder().map(Temporary::from_rooted));
+                let content = Node::collect_text_contents(self.traverse_preorder());
                 Some(content)
             }
             NodeTypeId::Comment |
@@ -2233,11 +2255,12 @@ impl<'a> NodeMethods for JSRef<'a, Node> {
 
             let lastself = lastself.root();
             for child in lastself.r().traverse_preorder() {
-                if child == other {
+                let child = child.root();
+                if child.r() == other {
                     // step 6.
                     return NodeConstants::DOCUMENT_POSITION_PRECEDING;
                 }
-                if child == self {
+                if child.r() == self {
                     // step 7.
                     return NodeConstants::DOCUMENT_POSITION_FOLLOWING;
                 }
@@ -2308,7 +2331,7 @@ impl<'a> style::node::TNode<'a> for JSRef<'a, Node> {
     fn parent_node(self) -> Option<JSRef<'a, Node>> {
         // FIXME(zwarich): Remove this when UFCS lands and there is a better way
         // of disambiguating methods.
-        fn parent_node<'a, T: NodeHelpers<'a>>(this: T) -> Option<Temporary<Node>> {
+        fn parent_node<'a, T: NodeHelpers>(this: T) -> Option<Temporary<Node>> {
             this.parent_node()
         }
 
@@ -2318,7 +2341,7 @@ impl<'a> style::node::TNode<'a> for JSRef<'a, Node> {
     fn first_child(self) -> Option<JSRef<'a, Node>> {
         // FIXME(zwarich): Remove this when UFCS lands and there is a better way
         // of disambiguating methods.
-        fn first_child<'a, T: NodeHelpers<'a>>(this: T) -> Option<Temporary<Node>> {
+        fn first_child<'a, T: NodeHelpers>(this: T) -> Option<Temporary<Node>> {
             this.first_child()
         }
 
@@ -2328,7 +2351,7 @@ impl<'a> style::node::TNode<'a> for JSRef<'a, Node> {
     fn last_child(self) -> Option<JSRef<'a, Node>> {
         // FIXME(zwarich): Remove this when UFCS lands and there is a better way
         // of disambiguating methods.
-        fn last_child<'a, T: NodeHelpers<'a>>(this: T) -> Option<Temporary<Node>> {
+        fn last_child<'a, T: NodeHelpers>(this: T) -> Option<Temporary<Node>> {
             this.last_child()
         }
 
@@ -2338,7 +2361,7 @@ impl<'a> style::node::TNode<'a> for JSRef<'a, Node> {
     fn prev_sibling(self) -> Option<JSRef<'a, Node>> {
         // FIXME(zwarich): Remove this when UFCS lands and there is a better way
         // of disambiguating methods.
-        fn prev_sibling<'a, T: NodeHelpers<'a>>(this: T) -> Option<Temporary<Node>> {
+        fn prev_sibling<'a, T: NodeHelpers>(this: T) -> Option<Temporary<Node>> {
             this.prev_sibling()
         }
 
@@ -2348,7 +2371,7 @@ impl<'a> style::node::TNode<'a> for JSRef<'a, Node> {
     fn next_sibling(self) -> Option<JSRef<'a, Node>> {
         // FIXME(zwarich): Remove this when UFCS lands and there is a better way
         // of disambiguating methods.
-        fn next_sibling<'a, T: NodeHelpers<'a>>(this: T) -> Option<Temporary<Node>> {
+        fn next_sibling<'a, T: NodeHelpers>(this: T) -> Option<Temporary<Node>> {
             this.next_sibling()
         }
 
@@ -2358,7 +2381,7 @@ impl<'a> style::node::TNode<'a> for JSRef<'a, Node> {
     fn is_document(self) -> bool {
         // FIXME(zwarich): Remove this when UFCS lands and there is a better way
         // of disambiguating methods.
-        fn is_document<'a, T: NodeHelpers<'a>>(this: T) -> bool {
+        fn is_document<'a, T: NodeHelpers>(this: T) -> bool {
             this.is_document()
         }
 
@@ -2368,7 +2391,7 @@ impl<'a> style::node::TNode<'a> for JSRef<'a, Node> {
     fn is_element(self) -> bool {
         // FIXME(zwarich): Remove this when UFCS lands and there is a better way
         // of disambiguating methods.
-        fn is_element<'a, T: NodeHelpers<'a>>(this: T) -> bool {
+        fn is_element<'a, T: NodeHelpers>(this: T) -> bool {
             this.is_element()
         }
 
diff --git a/components/script/dom/nodelist.rs b/components/script/dom/nodelist.rs
index 84aa5d6e2ea..8826733cfa6 100644
--- a/components/script/dom/nodelist.rs
+++ b/components/script/dom/nodelist.rs
@@ -6,6 +6,7 @@ use dom::bindings::codegen::Bindings::NodeListBinding;
 use dom::bindings::codegen::Bindings::NodeListBinding::NodeListMethods;
 use dom::bindings::global::GlobalRef;
 use dom::bindings::js::{JS, JSRef, Temporary};
+use dom::bindings::trace::RootedVec;
 use dom::bindings::utils::{Reflector, reflect_dom_object};
 use dom::node::{Node, NodeHelpers};
 use dom::window::Window;
@@ -38,8 +39,8 @@ impl NodeList {
                            GlobalRef::Window(window), NodeListBinding::Wrap)
     }
 
-    pub fn new_simple_list(window: JSRef<Window>, elements: Vec<JSRef<Node>>) -> Temporary<NodeList> {
-        NodeList::new(window, NodeListType::Simple(elements.iter().map(|element| JS::from_rooted(*element)).collect()))
+    pub fn new_simple_list(window: JSRef<Window>, elements: &RootedVec<JS<Node>>) -> Temporary<NodeList> {
+        NodeList::new(window, NodeListType::Simple((**elements).clone()))
     }
 
     pub fn new_child_list(window: JSRef<Window>, node: JSRef<Node>) -> Temporary<NodeList> {
diff --git a/components/script/script_task.rs b/components/script/script_task.rs
index 93d176e3b18..40eae7e0f74 100644
--- a/components/script/script_task.rs
+++ b/components/script/script_task.rs
@@ -24,7 +24,7 @@ use dom::bindings::codegen::Bindings::DocumentBinding::{DocumentMethods, Documen
 use dom::bindings::codegen::InheritTypes::{ElementCast, EventTargetCast, HTMLIFrameElementCast, NodeCast, EventCast};
 use dom::bindings::conversions::FromJSValConvertible;
 use dom::bindings::conversions::StringificationBehavior;
-use dom::bindings::js::{JS, JSRef, Temporary, OptionalRootable, RootedReference};
+use dom::bindings::js::{JS, JSRef, OptionalRootable, RootedReference};
 use dom::bindings::js::{RootCollection, RootCollectionPtr};
 use dom::bindings::refcounted::{LiveDOMReferences, Trusted, TrustedReference};
 use dom::bindings::structuredclone::StructuredCloneData;
@@ -811,9 +811,8 @@ impl ScriptTask {
             let doc: JSRef<Node> = NodeCast::from_ref(doc.r());
 
             doc.traverse_preorder()
-               .filter_map(HTMLIFrameElementCast::to_ref)
-               .find(|node| node.subpage_id() == Some(subpage_id))
-               .map(Temporary::from_rooted)
+               .filter_map(HTMLIFrameElementCast::to_temporary)
+               .find(|node| node.root().r().subpage_id() == Some(subpage_id))
         }).root();
 
         if let Some(frame_element) = frame_element {
@@ -832,9 +831,8 @@ impl ScriptTask {
             let doc: JSRef<Node> = NodeCast::from_ref(doc.r());
 
             doc.traverse_preorder()
-               .filter_map(HTMLIFrameElementCast::to_ref)
-               .find(|node| node.subpage_id() == Some(old_subpage_id))
-               .map(Temporary::from_rooted)
+               .filter_map(HTMLIFrameElementCast::to_temporary)
+               .find(|node| node.root().r().subpage_id() == Some(old_subpage_id))
         }).root();
 
         frame_element.unwrap().r().update_subpage_id(new_subpage_id);
@@ -952,10 +950,9 @@ impl ScriptTask {
                     let doc: JSRef<Node> = NodeCast::from_ref(doc.r());
 
                     doc.traverse_preorder()
-                       .filter_map(HTMLIFrameElementCast::to_ref)
-                       .find(|node| node.subpage_id() == Some(subpage_id))
-                       .map(ElementCast::from_ref)
-                       .map(Temporary::from_rooted)
+                       .filter_map(HTMLIFrameElementCast::to_temporary)
+                       .find(|node| node.root().r().subpage_id() == Some(subpage_id))
+                       .map(ElementCast::from_temporary)
                 })
             })
         }).root();
@@ -1218,9 +1215,8 @@ impl ScriptTask {
                     let doc: JSRef<Node> = NodeCast::from_ref(doc.r());
 
                     doc.traverse_preorder()
-                       .filter_map(HTMLIFrameElementCast::to_ref)
-                       .find(|node| node.subpage_id() == Some(subpage_id))
-                       .map(Temporary::from_rooted)
+                       .filter_map(HTMLIFrameElementCast::to_temporary)
+                       .find(|node| node.root().r().subpage_id() == Some(subpage_id))
                 }).root();
                 if let Some(iframe) = iframe.r() {
                     iframe.navigate_child_browsing_context(load_data.url);