server: fix ws memory leak (fixes socketio#268)

Author: rauchg

lib/server.js

@@ -49,7 +49,7 @@ function Server(opts){
   if (~this.transports.indexOf('websocket')) {
     this.ws = new WebSocketServer({ noServer: true, clientTracking: false });
   }
-};
+}
 
 /**
  * Protocol errors mappings.
@@ -268,7 +268,7 @@ Server.prototype.handshake = function(transport, req){
  * @api public
  */
 
-Server.prototype.handleUpgrade = function(req, socket, head){
+Server.prototype.handleUpgrade = function(req, socket, upgradeHead){
   this.prepare(req);
 
   var self = this;
@@ -278,8 +278,12 @@ Server.prototype.handleUpgrade = function(req, socket, head){
       return;
     }
 
+    var head = new Buffer(upgradeHead.length);
+    upgradeHead.copy(head);
+    upgradeHead = null;
+
     // delegate to ws
-    self.ws.handleUpgrade(req, socket, head, function(conn){
+    self.ws.handleUpgrade(req, socket, upgradeHead, function(conn){
       self.onWebSocket(req, conn);
     });
   });