events: separate maxListeners and _events

Fixes #1479.
Fixes #1923.

lib/events.js

@@ -33,7 +33,7 @@ exports.EventEmitter = EventEmitter;
 var defaultMaxListeners = 10;
 EventEmitter.prototype.setMaxListeners = function(n) {
   if (!this._events) this._events = {};
-  this._events.maxListeners = n;
+  this._maxListeners = n;
 };
 
 
@@ -118,8 +118,8 @@ EventEmitter.prototype.addListener = function(type, listener) {
     // Check for listener leak
     if (!this._events[type].warned) {
       var m;
-      if (this._events.maxListeners !== undefined) {
+      if (this._maxListeners !== undefined) {
-        m = this._events.maxListeners;
+        m = this._maxListeners;
       } else {
         m = defaultMaxListeners;
       }

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

@@ -0,0 +1,41 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+var common = require('../common');
+var assert = require('assert');
+var events = require('events');
+
+var gotEvent = false;
+
+process.on('exit', function() {
+  assert(gotEvent);
+});
+
+var e = new events.EventEmitter();
+
+e.on('maxListeners', function() {
+  gotEvent = true;
+});
+
+// Should not corrupt the 'maxListeners' queue.
+e.setMaxListeners(42);
+
+e.emit('maxListeners');