looks like there are sometimes objects passed into post presenter that respond to root while root is nil

app/presenters/post_presenter.rb

@@ -60,7 +60,7 @@ class PostPresenter
   end
 
   def root
-    PostPresenter.new(@post.root, current_user).as_json if @post.respond_to?(:root)
+    PostPresenter.new(@post.root, current_user).as_json if @post.respond_to?(:root) && @post.root.present?
   end
 
   def user_like
@@ -102,4 +102,4 @@ class PostInteractionPresenter
       element.as_api_response(:backbone)
     end
   end
-end
+end

spec/presenters/post_presenter_spec.rb

@@ -42,7 +42,17 @@ describe PostPresenter do
       @unauthenticated_presenter.user_reshare.should be_nil
     end
   end
-
+  
+  describe '#root' do
+    it 'does not raise if the root does not exists' do
+      reshare = Factory :reshare
+      reshare.root = nil
+      expect {
+        PostPresenter.new(reshare).root
+      }.to_not raise_error
+    end
+  end
+  
   describe '#next_post_path' do
     it 'returns a string of the users next post' do
       @presenter.next_post_path.should == "#{Rails.application.routes.url_helpers.post_path(@sm)}/next"
@@ -71,4 +81,4 @@ describe PostPresenter do
       end
     end
   end
-end
+end