fix(jqLite): support unbind self within handler

If an event handler unbinds itself, the next event handler on the same
event and element doesn't get executed.

This works fine in jQuery, and since jqLite doesn't support .one, this
might be a common use case.

Author: chrisirhc

src/jqLite.js

@@ -645,7 +645,10 @@ function createEventHandler(element, events) {
       return event.defaultPrevented || event.returnValue === false;
     };
 
-    forEach(events[type || event.type], function(fn) {
+    // Copy event handlers in case event handlers array is modified during execution.
+    var eventHandlersCopy = shallowCopy(events[type || event.type] || []);
+
+    forEach(eventHandlersCopy, function(fn) {
       fn.call(element, event);
     });
 

test/jqLiteSpec.js

@@ -1120,6 +1120,26 @@ describe('jqLite', function() {
     });
 
 
+    it('should deregister specific listener within the listener and call subsequent listeners', function() {
+      var aElem = jqLite(a),
+          clickSpy = jasmine.createSpy('click'),
+          clickOnceSpy = jasmine.createSpy('clickOnce').andCallFake(function() {
+            aElem.off('click', clickOnceSpy);
+          });
+
+      aElem.on('click', clickOnceSpy);
+      aElem.on('click', clickSpy);
+
+      browserTrigger(a, 'click');
+      expect(clickOnceSpy).toHaveBeenCalledOnce();
+      expect(clickSpy).toHaveBeenCalledOnce();
+
+      browserTrigger(a, 'click');
+      expect(clickOnceSpy).toHaveBeenCalledOnce();
+      expect(clickSpy.callCount).toBe(2);
+    });
+
+
     it('should deregister specific listener for multiple types separated by spaces', function() {
       var aElem = jqLite(a),
           masterSpy = jasmine.createSpy('master'),