From 5bcc6aefad6e2eb30f87ec0b9e9ffcc236971b75 Mon Sep 17 00:00:00 2001
From: Long Yinan <lynweklm@gmail.com>
Date: Fri, 23 Oct 2015 00:45:38 +0800
Subject: [PATCH] fix(utils): should have no effect when called
 addEventListener/removeEventListener without eventListener.

---
 lib/utils.js               |  6 ++++++
 test/patch/element.spec.js | 14 ++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/lib/utils.js b/lib/utils.js
index 228c2f9b9..8e5b62493 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -96,6 +96,9 @@ function patchEventTargetMethods(obj) {
   // This is required for the addEventListener hook on the root zone.
   obj[keys.common.addEventListener] = obj.addEventListener;
   obj.addEventListener = function (eventName, handler, useCapturing) {
+    if (!handler) {
+      return;
+    }
     var eventType = eventName + (useCapturing ? '$capturing' : '$bubbling');
     var fn;
     //Ignore special listeners of IE11 & Edge dev tools, see https://github.com/angular/zone.js/issues/150
@@ -129,6 +132,9 @@ function patchEventTargetMethods(obj) {
   // This is required for the removeEventListener hook on the root zone.
   obj[keys.common.removeEventListener] = obj.removeEventListener;
   obj.removeEventListener = function (eventName, handler, useCapturing) {
+    if (!handler) {
+      return;
+    }
     var eventType = eventName + (useCapturing ? '$capturing' : '$bubbling');
     if (handler[boundFnsKey] && handler[boundFnsKey][eventType]) {
       var _bound = handler[boundFnsKey];
diff --git a/test/patch/element.spec.js b/test/patch/element.spec.js
index b90d172af..66fb876b3 100644
--- a/test/patch/element.spec.js
+++ b/test/patch/element.spec.js
@@ -113,6 +113,20 @@ describe('element', function () {
     expect(eventListener.handleEvent).not.toHaveBeenCalled();
   });
 
+  it('should have no effect while calling addEventListener without listener', function () {
+    expect(function() {
+      button.addEventListener('click', null);
+      button.addEventListener('click', undefined);
+    }).not.toThrowError();
+  });
+
+  it('should have no effect while calling removeEventListener without listener', function () {
+    expect(function() {
+      button.removeEventListener('click', null);
+      button.removeEventListener('click', undefined);
+    }).not.toThrowError();
+  });
+
 
   it('should only add a listener once for a given set of arguments', function() {
     var log = [];