anchor.diff: -<% nav_event = assigned_event.parent_or_self %>
  +<% nav_event = assigned_event.try(:parent_or_self) %>
   
     <div class="skip-link">
       <a href="#content" title="Skip to content">Skip to content</a>
  
positive.code:         <ul class="nav navbar-nav">
            <% if assigned_nonchild_events_by_date.count > 1 %>
              <li class="dropdown">
                <a href="#" class="dropdown-toggle year" data-toggle="dropdown"><%= nav_event.slug %><b class="caret"></b></a>
                <ul class="dropdown-menu">
                  <% assigned_nonchild_events_by_date.reverse.each do |event| %>
                    <%= content_tag(:li, link_to(event.slug, event_path(event), :class => 'year'), :class => (nav_event == event) ? 'active' : '') %>
  
negative.code:               </ul>
              </li>
            <% end %>
            <% if nav_event %>
              <li><%= link_to nav_title(nav_event), nav_path(nav_event), :class => 'proposals_or_sessions' %></li>
              <% if nav_event.schedule_published? %>
              <li><%= link_to 'Schedule', event_schedule_path(nav_event), :class => 'schedule' %></li>
              <% end -%>
              <% if nav_event.proposal_status_published? %>
              <li><%= link_to 'Speakers', speakers_event_path(nav_event), :class => 'speakers' %></li>
              <% end -%>
              <% if bof = nav_event.children.first(:conditions => ['slug LIKE ?', '%bof']) %>
                <li><%= link_to 'BoFs', "/events/#{bof.slug}/#{bof.proposal_status_published? ? 'sessions' : 'proposals' }", :class => 'bofs' %></li>
              <% end %>
            <% end %>
          </ul>
          <ul class="nav navbar-nav navbar-right">
  