events: Don't crash on events named __proto__

This prefixes all event names internally with 'ev'.

lib/events.js

@@ -53,8 +53,8 @@ var PROCESS;
 EventEmitter.prototype.emit = function(type) {
   // If there is no 'error' event listener then throw.
   if (type === 'error') {
-    if (!this._events || !this._events.error ||
-        (isArray(this._events.error) && !this._events.error.length))
+    if (!this._events || !this._events.everror ||
+        (isArray(this._events.everror) && !this._events.everror.length))
     {
       if (this.domain) {
         var er = arguments[1];
@@ -75,7 +75,8 @@ EventEmitter.prototype.emit = function(type) {
   }
 
   if (!this._events) return false;
-  var handler = this._events[type];
+  var evtype = 'ev' + type;
+  var handler = this._events[evtype];
   if (!handler) return false;
 
   if (typeof handler == 'function') {
@@ -142,36 +143,37 @@ EventEmitter.prototype.addListener = function(type, listener) {
 
   // To avoid recursion in the case that type == "newListener"! Before
   // adding it to the listeners, first emit "newListener".
-  if (this._events.newListener) {
+  if (this._events.evnewListener) {
     this.emit('newListener', type, typeof listener.listener === 'function' ?
               listener.listener : listener);
   }
 
-  if (!this._events[type]) {
+  var evtype = 'ev' + type;
+  if (!this._events[evtype]) {
     // Optimize the case of one listener. Don't need the extra array object.
-    this._events[type] = listener;
-  } else if (isArray(this._events[type])) {
+    this._events[evtype] = listener;
+  } else if (isArray(this._events[evtype])) {
 
     // If we've already got an array, just append.
-    this._events[type].push(listener);
+    this._events[evtype].push(listener);
 
   } else {
     // Adding the second element, need to change to array.
-    this._events[type] = [this._events[type], listener];
+    this._events[evtype] = [this._events[evtype], listener];
 
   }
 
   // Check for listener leak
-  if (isArray(this._events[type]) && !this._events[type].warned) {
+  if (isArray(this._events[evtype]) && !this._events[evtype].warned) {
     var m;
     m = this._maxListeners;
 
-    if (m && m > 0 && this._events[type].length > m) {
-      this._events[type].warned = true;
+    if (m && m > 0 && this._events[evtype].length > m) {
+      this._events[evtype].warned = true;
       console.error('(node) warning: possible EventEmitter memory ' +
                     'leak detected. %d listeners added. ' +
                     'Use emitter.setMaxListeners() to increase limit.',
-                    this._events[type].length);
+                    this._events[evtype].length);
       console.trace();
     }
   }
@@ -204,10 +206,11 @@ EventEmitter.prototype.removeListener = function(type, listener) {
     throw new Error('removeListener only takes instances of Function');
   }
 
-  // does not use listeners(), so no side effect of creating _events[type]
-  if (!this._events || !this._events[type]) return this;
+  var evtype = 'ev' + type;
+  // does not use listeners(), so no side effect of creating _events[evtype]
+  if (!this._events || !this._events[evtype]) return this;
 
-  var list = this._events[type];
+  var list = this._events[evtype];
 
   if (isArray(list)) {
     var position = -1;
@@ -223,17 +226,17 @@ EventEmitter.prototype.removeListener = function(type, listener) {
     if (position < 0) return this;
     list.splice(position, 1);
     if (list.length == 0)
-      this._events[type] = null;
+      this._events[evtype] = null;
 
-    if (this._events.removeListener) {
+    if (this._events.evremoveListener) {
       this.emit('removeListener', type, listener);
     }
   } else if (list === listener ||
              (list.listener && list.listener === listener))
   {
-    this._events[type] = null;
+    this._events[evtype] = null;
 
-    if (this._events.removeListener) {
+    if (this._events.evremoveListener) {
       this.emit('removeListener', type, listener);
     }
   }
@@ -245,27 +248,28 @@ EventEmitter.prototype.removeAllListeners = function(type) {
   if (!this._events) return this;
 
   // fast path
-  if (!this._events.removeListener) {
+  if (!this._events.evremoveListener) {
     if (arguments.length === 0) {
       this._events = {};
-    } else if (type && this._events && this._events[type]) {
-      this._events[type] = null;
+    } else if (type && this._events && this._events['ev' + type]) {
+      this._events['ev' + type] = null;
     }
     return this;
   }
 
   // slow(ish) path, emit 'removeListener' events for all removals
   if (arguments.length === 0) {
     for (var key in this._events) {
-      if (key === 'removeListener') continue;
-      this.removeAllListeners(key);
+      if (key === 'evremoveListener') continue;
+      this.removeAllListeners(key.slice(2));
     }
     this.removeAllListeners('removeListener');
     this._events = {};
     return this;
   }
 
-  var listeners = this._events[type];
+  var evtype = 'ev' + type;
+  var listeners = this._events[evtype];
   if (isArray(listeners)) {
     while (listeners.length) {
       // LIFO order
@@ -274,15 +278,16 @@ EventEmitter.prototype.removeAllListeners = function(type) {
   } else if (listeners) {
     this.removeListener(type, listeners);
   }
-  this._events[type] = null;
+  this._events[evtype] = null;
 
   return this;
 };
 
 EventEmitter.prototype.listeners = function(type) {
-  if (!this._events || !this._events[type]) return [];
-  if (!isArray(this._events[type])) {
-    return [this._events[type]];
+  var evtype = 'ev' + type;
+  if (!this._events || !this._events[evtype]) return [];
+  if (!isArray(this._events[evtype])) {
+    return [this._events[evtype]];
   }
-  return this._events[type].slice(0);
+  return this._events[evtype].slice(0);
 };

test/simple/test-event-emitter-check-listener-leaks.js

@@ -29,30 +29,30 @@ var e = new events.EventEmitter();
 for (var i = 0; i < 10; i++) {
   e.on('default', function() {});
 }
-assert.ok(!e._events['default'].hasOwnProperty('warned'));
+assert.ok(!e._events.evdefault.hasOwnProperty('warned'));
 e.on('default', function() {});
-assert.ok(e._events['default'].warned);
+assert.ok(e._events.evdefault.warned);
 
 // specific
 e.setMaxListeners(5);
 for (var i = 0; i < 5; i++) {
   e.on('specific', function() {});
 }
-assert.ok(!e._events['specific'].hasOwnProperty('warned'));
+assert.ok(!e._events.evspecific.hasOwnProperty('warned'));
 e.on('specific', function() {});
-assert.ok(e._events['specific'].warned);
+assert.ok(e._events.evspecific.warned);
 
 // only one
 e.setMaxListeners(1);
 e.on('only one', function() {});
-assert.ok(!e._events['only one'].hasOwnProperty('warned'));
+assert.ok(!e._events['evonly one'].hasOwnProperty('warned'));
 e.on('only one', function() {});
-assert.ok(e._events['only one'].hasOwnProperty('warned'));
+assert.ok(e._events['evonly one'].hasOwnProperty('warned'));
 
 // unlimited
 e.setMaxListeners(0);
 for (var i = 0; i < 1000; i++) {
   e.on('unlimited', function() {});
 }
-assert.ok(!e._events['unlimited'].hasOwnProperty('warned'));
+assert.ok(!e._events['evunlimited'].hasOwnProperty('warned'));
 

test/simple/test-event-emitter-listeners-side-effects.js

@@ -37,21 +37,21 @@ assert.equal(e._events, null);
 
 e.on('foo', assert.fail);
 fl = e.listeners('foo');
-assert(e._events.foo === assert.fail);
+assert(e._events.evfoo === assert.fail);
 assert(Array.isArray(fl));
 assert(fl.length === 1);
 assert(fl[0] === assert.fail);
 
 e.listeners('bar');
-assert(!e._events.hasOwnProperty('bar'));
+assert(!e._events.hasOwnProperty('evbar'));
 
 e.on('foo', assert.ok);
 fl = e.listeners('foo');
 
-assert(Array.isArray(e._events.foo));
-assert(e._events.foo.length === 2);
-assert(e._events.foo[0] === assert.fail);
-assert(e._events.foo[1] === assert.ok);
+assert(Array.isArray(e._events.evfoo));
+assert(e._events.evfoo.length === 2);
+assert(e._events.evfoo[0] === assert.fail);
+assert(e._events.evfoo[1] === assert.ok);
 
 assert(Array.isArray(fl));
 assert(fl.length === 2);

test/simple/test-event-emitter-prototype-property.js

@@ -0,0 +1,37 @@
+// 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 e = new events.EventEmitter();
+
+var emited = false;
+e.on('__proto__', function() {
+  emited = true;
+});
+
+e.emit('__proto__');
+
+process.on('exit', function() {
+  assert.equal(true, emited);
+});