Buffer-type chunks: support concatenation

Author: tchakabam

lib/index.js

@@ -513,10 +513,14 @@ NodeHttpXHR.prototype.send = function (data) {
       if (typeof chunk === 'string') {
         this._responseText += chunk;
       } else if (typeof chunk === 'object') {
-        // binary data usually comes in one chunk (no chunky transfer-encoding)
-        // or at least, that's what we'll support here for now
         if (chunk instanceof Buffer) {
-          this._response = chunk.buffer;
+          if (this._response) {
+            this._response = Buffer.concat([this._response, chunk]);
+          } else {
+            this._response = chunk;
+          }
+        // binary data usually comes in one chunk (no chunky transfer-encoding)
+        // or at least, that's what we'll support here for now for ArrayBuffer
         } else if (chunk instanceof ArrayBuffer) {
           this._response = chunk;
         } else {