Fixed bug with sidebar when user is not logged in

app/helpers/issuables_helper.rb

@@ -78,8 +78,10 @@ module IssuablesHelper
   end
 
   def has_todo(issuable)
+    unless current_user.nil?
       current_user.todos.find_by(target_id: issuable.id, state: :pending)
     end
+  end
 
   private
 

app/views/shared/issuable/_sidebar.html.haml

@@ -3,10 +3,12 @@
   .issuable-sidebar
     - can_edit_issuable = can?(current_user, :"admin_#{issuable.to_ability_name}", @project)
     .block.issuable-sidebar-header
+      - if current_user
         %span.issuable-header-text.hide-collapsed.pull-left
           Todo
       %a.gutter-toggle.pull-right.js-sidebar-toggle{ role: "button", href: "#", aria: { label: "Toggle sidebar" } }
         = sidebar_gutter_toggle_icon
+      - if current_user
         %button.btn.btn-default.issuable-header-btn.pull-right.js-issuable-todo{ type: "button", data: { todo_text: "Add Todo", mark_text: "Mark Done", id: (todo.id unless todo.nil?), url: issuable_todo_path(issuable) } }
           - if todo.nil?
             %span