From a09fa356416c033a52666f3becf00524ecff3a03 Mon Sep 17 00:00:00 2001
From: Igor Minar <igor@angularjs.org>
Date: Sun, 10 Aug 2014 07:08:57 -0700
Subject: [PATCH] perf(Scope): exit $broadcast early if nobody is listening for
 the given event

---
 src/ng/rootScope.js | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/ng/rootScope.js b/src/ng/rootScope.js
index 2b369d44..23fd7bf0 100644
--- a/src/ng/rootScope.js
+++ b/src/ng/rootScope.js
@@ -1148,8 +1148,11 @@ function $RootScopeProvider(){
                 event.defaultPrevented = true;
               },
               defaultPrevented: false
-            },
-            listenerArgs = concat([event], arguments, 1),
+            };
+
+        if (!target.$$listenerCount[name]) return event;
+
+        var listenerArgs = concat([event], arguments, 1),
             listeners, i, length;
 
         //down while you can, then up and next sibling or up and next sibling until back at root