A reshares root may be already gone when generating the notification

app/models/reshare.rb

@@ -62,7 +62,7 @@ class Reshare < Post
   end
 
   def notification_type(user, person)
-    Notifications::Reshared if root.author == user.person
+    Notifications::Reshared if root.try(:author) == user.person
   end
 
   def absolute_root

spec/models/reshare_spec.rb

@@ -75,6 +75,13 @@ describe Reshare, :type => :model do
     it 'returns "Reshared" for the original post author' do
       expect(@reshare.notification_type(alice, @reshare.author)).to eq(Notifications::Reshared)
     end
+
+    it 'does not error out if the root was deleted' do
+      @reshare.root = nil
+      expect {
+        @reshare.notification_type(alice, @reshare.author)
+      }.to_not raise_error
+    end
   end
 
   describe '#absolute_root' do