修复了刷新实训相关页面出现500的bug

app/controllers/application_controller.rb

@@ -1141,4 +1141,9 @@ class ApplicationController < ActionController::Base
 
     redirect_to authorize_url
   end
+
+  def user_login_and_from_openi
+    url = request.referer.nil? ? Redmine::Configuration['educoder_domain'] : request.referer
+    URI(url).host == 'openi.org.cn' && !current_user.logged?
+  end
 end

app/controllers/challenges_controller.rb

@@ -1,6 +1,8 @@
 # encoding: utf-8
 class ChallengesController < ApplicationController
   layout "base_shixun"
+  # 如要添加或修改before_filter时，请将handle_openi_request这个before_filter放至第一位
+  before_filter :handle_openi_request, if: -> { user_login_and_from_openi }
   before_filter :check_authentication, :except => [:index]
   before_filter :find_shixun, :only => [:index, :new, :create, :destroy, :challenge_build, :update_evaluation, :add_choose_question, :new_choose_question,
                                           :choose_type_show, :edit_choose_question, :update_choose_question, :destroy_challenge_choose]

app/controllers/shixuns_controller.rb

@@ -3,7 +3,7 @@
 class ShixunsController < ApplicationController
   layout 'base_shixun'
   # 如要添加或修改before_filter时，请将handle_openi_request这个before_filter放至第一位
-  before_filter :handle_openi_request, if: -> {URI(request.referer).host == 'openi.org.cn' && !current_user.logged?}
+  before_filter :handle_openi_request, if: -> { user_login_and_from_openi }
   before_filter :require_login, :except => [:ghook, :download_file, :show, :index]
   before_filter :check_authentication, :except => [:ghook, :download_file, :show, :index]
   before_filter :find_shixun, :except => [ :index, :new, :create, :index, :search, :shixun_courses, :new_disscuss, :shixun_migrate, :qrcode, :download_file, :departments, :get_mirror_script, :send_message_to_administrator]

app/controllers/subjects_controller.rb

@@ -2,7 +2,7 @@
 class SubjectsController < ApplicationController
   layout 'base_subject'
   # 如要添加或修改before_filter时，请将handle_openi_request这个before_filter放至第一位
-  before_filter :handle_openi_request, if: -> {URI(request.referer).host == 'openi.org.cn' && !current_user.logged?}
+  before_filter :handle_openi_request, if: -> { user_login_and_from_openi }
   before_filter :require_login, :except => [:show, :index]
   before_filter :check_authentication, :except => [:show, :index]
   before_filter :find_subject, :except => [:index, :new, :create, :create_subject, :new_subject, :append_to_stage, :send_to_course]