解决资源总数为负数的问题

app/models/attachment.rb

@@ -643,8 +643,13 @@ class Attachment < ActiveRecord::Base
 
   def decrease_attchments_count
     if self.container_type == "Project" && !self.project.project_score.nil?
-      aatach_count = self.container.project_score.attach_num - 1
-      self.container.project_score.update_attribute(:attach_num, aatach_count)
+      attach_count = self.container.project_score.attach_num - 1
+      if attach_count < 0
+        self.container.project_score.update_attribute(:attach_num, 0)
+      else
+        self.container.project_score.update_attribute(:attach_num, attach_count)
+      end
+
     end
   end
 end