修复分页问题

app/helpers/users_helper.rb

@@ -57,25 +57,27 @@ module UsersHelper
   def get_resource_origin attach
     type = attach.container_type
     content = attach.container
-    case type
-      when 'Course'
-        result = current_time_and_term_resource content
-      when 'Project'
-        result = content.name
-      when 'Issue'
-        result = content.subject
-      when 'Message'
-        result = content.subject
-      when 'News'
-        result = content.title
-      when 'HomewCommon'
-        result = content.name
-      when 'StudentWorkScore'
-        result = content.name
-      when 'Principal'
-        result = content.name
-      when 'OrgSubfield'
-        result = content.name
+    unless content.nil?
+      case type
+        when 'Course'
+          result = current_time_and_term_resource content
+        when 'Project'
+          result = content.name
+        when 'Issue'
+          result = content.subject
+        when 'Message'
+          result = content.subject
+        when 'News'
+          result = content.title
+        when 'HomewCommon'
+          result = content.name
+        when 'StudentWorkScore'
+          result = content.name
+        when 'Principal'
+          result = content.name
+        when 'OrgSubfield'
+          result = content.name
+      end
     end
   end