Add headers on 'handshake'

The headers in the 'handshake' event were not written to the socket, the client received data but not the headers.

lib/node-http-proxy/http-proxy.js

@@ -698,6 +698,15 @@ HttpProxy.prototype.proxyWebSocketRequest = function (req, socket, upgradeHead,
     socket: socket,
     head: head
   };
+
+  //
+  // Here we set the handshake `headers` and `statusCode` data to the outgoing
+  // request so that we can reuse this data later.
+  //
+  reverseProxy.handshake = {
+    headers: {},
+    statusCode: null,
+  }
 
   //
   // If the agent for this particular `host` and `port` combination
@@ -707,7 +716,16 @@ HttpProxy.prototype.proxyWebSocketRequest = function (req, socket, upgradeHead,
   // In addition, it's important to note the closure scope here. Since
   // there is no mapping of the socket to the request bound to it.
   //
-  reverseProxy.on('upgrade', function (_, remoteSocket, head) {
+  reverseProxy.on('upgrade', function ( res, remoteSocket, head) {
+
+    //
+    // Prepare handshake response 'headers' and 'statusCode'.
+    //
+    reverseProxy.handshake = {
+      headers: res.headers,
+      statusCode: res.statusCode,
+    }
+
     //
     // Prepare the socket for the reverseProxy request and begin to
     // stream data between the two sockets. Here it is important to
@@ -723,6 +741,28 @@ HttpProxy.prototype.proxyWebSocketRequest = function (req, socket, upgradeHead,
   //
   reverseProxy.once('socket', function (revSocket) {
     revSocket.on('data', function handshake (data) {
+
+      // Set empty headers
+      var headers = '';
+
+      //
+      // If the handshake statusCode 101, concat headers.
+      //
+      if(reverseProxy.handshake.statusCode && reverseProxy.handshake.statusCode == 101){
+
+        headers = [
+                'HTTP/1.1 101 Switching Protocols'
+                , 'Upgrade: websocket'
+                , 'Connection: Upgrade'
+                , 'Sec-WebSocket-Accept: ' + reverseProxy.handshake.headers['sec-websocket-accept']
+        ];
+
+        headers = headers.concat('', '').join('\r\n');
+
+      }
+
+
+
       //
       // Ok, kind of harmfull part of code. Socket.IO sends a hash
       // at the end of handshake if protocol === 76, but we need
@@ -752,7 +792,8 @@ HttpProxy.prototype.proxyWebSocketRequest = function (req, socket, upgradeHead,
         // from the original incoming request.
         //
         self.emit('websocket:handshake', req, socket, head, sdata, data);
-        socket.write(sdata);
+        // add headers to the socket
+        socket.write(headers+sdata);
         var flushed = socket.write(data);
         if (!flushed) {
           revSocket.pause();