新增：工作项关联项目查询

app/models/project.rb

@@ -487,7 +487,7 @@ class Project < ApplicationRecord
   end
 
   def full_url
-    Rails.application.config_for(:configuration)['platform_url'] + '/' + self.owner.try(:login) + '/' + self.identifier
+    Rails.application.config_for(:configuration)['platform_url'].to_s + '/' + self.owner&.try(:login).to_s + '/' + self.identifier.to_s
   end
 
   def to_builder

app/views/api/v1/issues/_detail.json.jbuilder

@@ -59,7 +59,7 @@ json.pm_project_id issue.pm_project_id
 json.time_scale issue.time_scale
 json.child_count issue.child_count
 json.project do 
-  if issue.project.present? 
+  if issue.project.present? && issue.owner.present?
     json.partial! "api/v1/projects/detail", locals: {project: issue.project}
   else 
     json.nil!