From 37ddad508d7ac506cc0299494cfb2c2731a8fa59 Mon Sep 17 00:00:00 2001
From: Jeremy Ashkenas <jashkenas@gmail.com>
Date: Mon, 18 Apr 2011 16:39:26 -0400
Subject: [PATCH] Issue #309, more sophisticated event handling, for unbinding
 events in the midst of them firing.

---
 backbone.js    | 28 +++++++++++++++-------------
 test/events.js | 14 ++++++++++++++
 2 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/backbone.js b/backbone.js
index be202733..b064107e 100644
--- a/backbone.js
+++ b/backbone.js
@@ -90,7 +90,7 @@
           if (!list) return this;
           for (var i = 0, l = list.length; i < l; i++) {
             if (callback === list[i]) {
-              list.splice(i, 1);
+              list[i] = null;
               break;
             }
           }
@@ -102,19 +102,21 @@
     // Trigger an event, firing all bound callbacks. Callbacks are passed the
     // same arguments as `trigger` is, apart from the event name.
     // Listening for `"all"` passes the true event name as the first argument.
-    trigger : function(ev) {
-      var list, calls, i, l;
+    trigger : function(eventName) {
+      var list, calls, ev, callback, args, i, l;
+      var both = 2;
       if (!(calls = this._callbacks)) return this;
-      if (calls[ev]) {
-        list = calls[ev].slice(0);
-        for (i = 0, l = list.length; i < l; i++) {
-          list[i].apply(this, Array.prototype.slice.call(arguments, 1));
-        }
-      }
-      if (calls['all']) {
-        list = calls['all'].slice(0);
-        for (i = 0, l = list.length; i < l; i++) {
-          list[i].apply(this, arguments);
+      while (both--) {
+        ev = both ? eventName : 'all';
+        if (list = calls[ev]) {
+          for (i = 0, l = list.length; i < l; i++) {
+            if (!(callback = list[i])) {
+              list.splice(i, 1); i--; l--;
+            } else {
+              args = both ? Array.prototype.slice.call(arguments, 1) : arguments;
+              callback.apply(this, args);
+            }
+          }
         }
       }
       return this;
diff --git a/test/events.js b/test/events.js
index cdc8e8df..54189619 100644
--- a/test/events.js
+++ b/test/events.js
@@ -39,6 +39,20 @@ $(document).ready(function() {
     equals(obj.counterB, 2, 'counterB should have been incremented twice.');
   });
 
+  test("Events: unbind a callback in the midst of it firing", function() {
+    var obj = {counter: 0};
+    _.extend(obj, Backbone.Events);
+    var callback = function() {
+      obj.counter += 1;
+      obj.unbind('event', callback);
+    };
+    obj.bind('event', callback);
+    obj.trigger('event');
+    obj.trigger('event');
+    obj.trigger('event');
+    equals(obj.counter, 1, 'the callback should have been unbound.');
+  });
+
   test("Events: two binds that unbind themeselves", function() {
     var obj = { counterA: 0, counterB: 0 };
     _.extend(obj,Backbone.Events);