setMaxListeners should initialize _events

lib/events.js

@@ -9,6 +9,7 @@ var isArray = Array.isArray;
 // that to be increased. Set to zero for unlimited.
 var defaultMaxListeners = 10;
 EventEmitter.prototype.setMaxListeners = function(n) {
+  if (!this._events) this._events = {};
   this._events.maxListeners = n;
 };
 

test/simple/test-event-emitter-add-listeners.js

@@ -23,6 +23,12 @@ console.log('start');
 
 e.emit('hello', 'a', 'b');
 
+
+// just make sure that this doesn't throw:
+var f = new events.EventEmitter();
+f.setMaxListeners(0);
+
+
 process.addListener('exit', function() {
   assert.deepEqual(['hello'], events_new_listener_emited);
   assert.equal(1, times_hello_emited);