#1647 正式版--资源搜索窗口搜索课程资源进行下载返回500错误（资源可见性判断修复）

app/models/course.rb

@@ -7,7 +7,7 @@ class Course < ActiveRecord::Base
   STATUS_ARCHIVED   = 9
   
   attr_accessible :code, :extra, :name, :state, :tea_id, :time , :location, :state, :term, :password,:is_public,:description,:class_period, :open_student
-  belongs_to :project, :class_name => 'Course', :foreign_key => :extra, primary_key: :identifier
+  #belongs_to :project, :class_name => 'Course', :foreign_key => :extra, primary_key: :identifier
   belongs_to :teacher, :class_name => 'User', :foreign_key => :tea_id  # 定义一个方法teacher，该方法通过tea_id来调用User表
   belongs_to :school, :class_name => 'School', :foreign_key => :school_id #定义一个方法school，该方法通过school_id来调用School表
   has_many :bid
@@ -31,7 +31,7 @@ class Course < ActiveRecord::Base
 
   acts_as_taggable
   acts_as_nested_set :order => 'name', :dependent => :destroy
-  acts_as_attachable :view_permission => :view_files,
+  acts_as_attachable :view_permission => :view_course_files,
                      :delete_permission => :manage_files
 
   validates_presence_of :password, :term,:name,:description

lib/plugins/acts_as_attachable/lib/acts_as_attachable.rb

@@ -46,6 +46,9 @@ module Redmine
           if self.respond_to?(:project)
             (respond_to?(:visible?) ? visible?(user) : true) &&
                 user.allowed_to?(self.class.attachable_options[:view_permission], self.project)
+          elsif self.is_a?(Course)
+            (respond_to?(:visible?) ? visible?(user) : true) &&
+              user.allowed_to?(self.class.attachable_options[:view_permission], self)
           else
             return true
           end