diff --git a/app/controllers/issues_controller.rb b/app/controllers/issues_controller.rb
index f6a96ebb8..9e75eb0d6 100644
--- a/app/controllers/issues_controller.rb
+++ b/app/controllers/issues_controller.rb
@@ -292,14 +292,20 @@ class IssuesController < ApplicationController
 
   def update_user_issue_detail(issue, params)
     case params[:type]
-    when "status"
-      issue.update_attribute(:status_id, params[:status_id])
-    when "assigned"
-      issue.update_attribute(:assigned_to_id, params[:assigned_to_id])
-    when "ratio"
-      issue.update_attribute(:done_ratio, params[:done_ratio])
-    when "prior"
-      issue.update_attribute(:priority_id, params[:priority_id])
+      when "status"
+        if   params[:status_id] != "0"
+          issue.update_attribute(:status_id, params[:status_id])
+        end
+      when "assigned"
+        if   params[:assigned_to_id] != "0"
+          issue.update_attribute(:assigned_to_id, params[:assigned_to_id])
+        end
+      when "ratio"
+        issue.update_attribute(:done_ratio, params[:done_ratio])
+      when "prior"
+        if   params[:priority_id] != "0"
+          issue.update_attribute(:priority_id, params[:priority_id])
+        end
     end
   end