From d00dc631f8a2570495eccdb9621a9d1cf405edf8 Mon Sep 17 00:00:00 2001
From: Naman Gupta <01namangupta@gmail.com>
Date: Sat, 21 Oct 2017 02:42:08 +0530
Subject: [PATCH] Error opening link to difficulty level in Revision history is
 removed

---
 app/helpers/versions_helper.rb                           | 9 +++++++++
 app/views/admin/versions/_object_desc_and_link.html.haml | 5 +----
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/app/helpers/versions_helper.rb b/app/helpers/versions_helper.rb
index 5788fe9d..7827a5ef 100644
--- a/app/helpers/versions_helper.rb
+++ b/app/helpers/versions_helper.rb
@@ -162,4 +162,13 @@ module VersionsHelper
   def users_role_change_description(version)
     version.event == 'create' ? 'added' : 'removed'
   end
+
+
+  def link_to_difficulty_level(version)
+    return 'deleted role' if version.conference_id.nil?
+    conference = Conference.find_by(id: version.conference_id)
+    difficulty_level = DifficultyLevel.find(version.item_id)
+      link_to difficulty_level.title,
+              admin_conference_program_difficulty_levels_path(conference.short_title)
+  end
 end
diff --git a/app/views/admin/versions/_object_desc_and_link.html.haml b/app/views/admin/versions/_object_desc_and_link.html.haml
index 4852a50f..7e24d8c2 100644
--- a/app/views/admin/versions/_object_desc_and_link.html.haml
+++ b/app/views/admin/versions/_object_desc_and_link.html.haml
@@ -207,10 +207,7 @@
 
 - when 'DifficultyLevel'
   difficulty level
-  - difficulty_level = current_or_last_object_state(version.item_type, version.item_id)
-  = link_if_alive version, difficulty_level.title,
-          admin_conference_program_difficulty_level_path(conference_short_title, version.item_id),
-          conference
+  = link_to_difficulty_level(version)
 
 - when 'Splashpage'
   = link_if_alive version, 'splashpage',