修复课程成员不能加入作业中私有资源的BUG

app/controllers/attachments_controller.rb

@@ -84,7 +84,10 @@ class AttachmentsController < ApplicationController
       candown= User.current.member_of_course?(course) || (course.is_public==1 && @attachment.is_public == 1)
     elsif @attachment.container.class.to_s=="HomeworkAttach" && @attachment.container.bid.reward_type == 3
       candown = true
+    elsif  @attachment.container_type == "Bid" && @attachment.container && @attachment.container.courses
+      candown = User.current.member_of_course?(@attachment.container.courses.first) || (course.is_public == 1 && @attachment.is_public == 1)
     else
+
       candown = @attachment.is_public == 1
     end
     if candown || User.current.admin? || User.current.id == @attachment.author_id