servo: Merge #5333 - Ensures that iframe navigation updates the parent iframe element subpage id (from glennw:fix-iframe-subpage); r=jdm

This fixes the case of clicking a link in an iframe, going back, then clicking the link again.

Source-Repo: https://github.com/servo/servo
Source-Revision: 2f85c5bb502c2582d34772db979e27c741ee76e3

servo/components/script/script_task.rs

@@ -652,6 +652,10 @@ impl ScriptTask {
                                                  subpage_id,
                                                  event_name,
                                                  event_detail),
+            ConstellationControlMsg::UpdateSubpageId(containing_pipeline_id,
+                                                     old_subpage_id,
+                                                     new_subpage_id) =>
+                self.handle_update_subpage_id(containing_pipeline_id, old_subpage_id, new_subpage_id),
         }
     }
 
@@ -817,6 +821,25 @@ impl ScriptTask {
         }
     }
 
+    fn handle_update_subpage_id(&self,
+                                containing_pipeline_id: PipelineId,
+                                old_subpage_id: SubpageId,
+                                new_subpage_id: SubpageId) {
+        let borrowed_page = self.root_page();
+
+        let frame_element = borrowed_page.find(containing_pipeline_id).and_then(|page| {
+            let doc = page.document().root();
+            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)
+        }).root();
+
+        frame_element.unwrap().r().update_subpage_id(new_subpage_id);
+    }
+
     /// Handles a notification that reflow completed.
     fn handle_reflow_complete_msg(&self, pipeline_id: PipelineId, reflow_id: uint) {
         debug!("Script: Reflow {:?} complete for {:?}", reflow_id, pipeline_id);