Don't leak aux data

src/servo/dom/rcu.rs

@@ -116,9 +116,6 @@ impl<T:send,A> Handle<T,A> {
     **Warning:** the reader is responsible for keeping this data live!
     ")]
     fn set_aux(p: @A) unsafe {
-        let p2 = p;
-        unsafe::forget(p2); // Bump the reference count.
-
         (**self).read_aux = ptr::addr_of(*p);
     }
 

src/servo/layout/layout_task.rs

@@ -29,6 +29,10 @@ enum Msg {
 
 fn LayoutTask(render_task: RenderTask, image_cache_task: ImageCacheTask) -> LayoutTask {
     do spawn_listener::<Msg>|request| {
+
+        // This just keeps our dom aux objects alive
+        let mut layout_data_refs = ~[];
+
         loop {
             match request.recv() {
               PingMsg(ping_channel) => ping_channel.send(content_task::PongMsg),
@@ -41,7 +45,7 @@ fn LayoutTask(render_task: RenderTask, image_cache_task: ImageCacheTask) -> Layo
                 node.dump();
 
                 do util::time::time(~"layout") {
-                    node.initialize_style_for_subtree();
+                    layout_data_refs += node.initialize_style_for_subtree();
                     node.recompute_style_for_subtree(styles);
 
                     let this_box = node.construct_boxes();

src/servo/layout/style/apply.rs

@@ -164,7 +164,6 @@ mod test {
     }
 
     #[test]
-    #[ignore(reason = "leaks memory")]
     fn test_percent_height() {
         let scope = NodeScope();
 
@@ -178,7 +177,7 @@ mod test {
         scope.add_child(parent, child2);
         scope.add_child(child, g1);
         scope.add_child(child, g2);
-        parent.initialize_style_for_subtree();
+        let _handles = parent.initialize_style_for_subtree();
 
         do parent.aux |aux| { aux.specified_style.height = some(Px(100.0)); }
         do child.aux |aux| { aux.specified_style.height = some(Auto); }

src/servo/layout/style/style.rs

@@ -75,7 +75,7 @@ fn empty_style_for_node_kind(kind: NodeKind) -> SpecifiedStyle {
 }
 
 trait StylePriv {
-    fn initialize_style();
+    fn initialize_style() -> ~[@LayoutData];
 }
 
 impl Node : StylePriv {
@@ -89,31 +89,39 @@ impl Node : StylePriv {
      "]
     // TODO: we should look into folding this into building the dom,
     // instead of doing a linear sweep afterwards.
-    fn initialize_style() {
-        let node_kind = self.read(|n| copy *n.kind);
-        let the_layout_data = @LayoutData({
-            mut specified_style : ~empty_style_for_node_kind(node_kind),
-            mut box : none
-        });
+    fn initialize_style() -> ~[@LayoutData] {
+        if !self.has_aux() {
+            let node_kind = self.read(|n| copy *n.kind);
+            let the_layout_data = @LayoutData({
+                mut specified_style : ~empty_style_for_node_kind(node_kind),
+                mut box : none
+            });
 
-        self.set_aux(the_layout_data);
+            self.set_aux(the_layout_data);
+
+            ~[the_layout_data]
+        } else {
+            ~[]
+        }
     }
 }
 
 trait StyleMethods {
-    fn initialize_style_for_subtree();
+    fn initialize_style_for_subtree() -> ~[@LayoutData];
     fn get_specified_style() -> SpecifiedStyle;
     fn recompute_style_for_subtree(styles : arc<Stylesheet>);
 }
 
 impl Node : StyleMethods {
     #[doc="Sequentially initialize the nodes' auxilliary data so they can be updated in parallel."]
-    fn initialize_style_for_subtree() {
-        self.initialize_style();
+    fn initialize_style_for_subtree() -> ~[@LayoutData] {
+        let mut handles = self.initialize_style();
         
         for NTree.each_child(self) |kid| {
-            kid.initialize_style_for_subtree();
+            handles += kid.initialize_style_for_subtree();
         }
+
+        return handles;
     }
     
     #[doc="