issue project 为nil时的特殊处理

app/models/issue.rb

@@ -187,7 +187,11 @@ class Issue < ApplicationRecord
   end
 
   def is_collaborators?
-    self.assigned_to_id.present? ? self.project.member?(self.assigned_to_id) : false
+    if self.assigned_to_id.present? && self.project.present?
+      self.project.member?(self.assigned_to_id)
+    else
+      false
+    end
   end
 
   def get_issue_tags_name
@@ -229,7 +233,7 @@ class Issue < ApplicationRecord
   end
 
   def update_closed_issues_count_in_project!
-    self.project.decrement!(:closed_issues_count) if self.status_id == 5
+    self.project.decrement!(:closed_issues_count) if self.status_id == 5 && self.project.present?
   end
 
   def send_update_message_to_notice_system