From 58ef29e8d520833efd7ae9b5456d7d1117f08706 Mon Sep 17 00:00:00 2001
From: Leo Horie <leohorie@hotmail.com>
Date: Thu, 25 Feb 2016 20:27:01 -0500
Subject: [PATCH] #931 prevent unloaders from being registered more than once

---
 mithril.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mithril.js b/mithril.js
index d023ac34..ce4f1951 100644
--- a/mithril.js
+++ b/mithril.js
@@ -736,7 +736,7 @@
 	var unloaders = []
 
 	function updateLists(views, controllers, view, controller) {
-		if (controller.onunload != null) {
+		if (controller.onunload != null && unloaders.map(function(u) {return u.handler}).indexOf(controller.onunload) < 0) {
 			unloaders.push({
 				controller: controller,
 				handler: controller.onunload