Call PaneContainer::itemAdded from PaneContainer::reopenItem

This ensures the active item in the new root is filtered out of
the reopen stack, preventing a duplicate item from being opened.

spec/pane-container-spec.coffee

@@ -149,6 +149,12 @@ describe "PaneContainer", ->
       expect(container.reopenItem()).toBeFalsy()
       expect(pane1.activeItem).toEqual item3
 
+      pane1.destroyItem(item3)
+      container.setRoot(new Pane(item3))
+      expect(container.reopenItem()).toBeFalsy()
+      expect(container.getActivePane().getItems().length).toBe 1
+      expect(container.getActivePaneItem()).toEqual item3
+
   describe ".saveAll()", ->
     it "saves all open pane items", ->
       pane1.showItem(new TestView('4'))

src/pane-container.coffee

@@ -96,7 +96,9 @@ class PaneContainer extends View
 
   setRoot: (root) ->
     @empty()
-    @append(root) if root?
+    if root?
+      @append(root)
+      @itemAdded(root.activeItem) if root.activeItem
     @state.set(root: root?.getState())
 
   removeChild: (child) ->