Fix test-http-buffer-sanity

lib/http.js

@@ -322,7 +322,7 @@ OutgoingMessage.prototype._send = function (data, encoding) {
     }
     this._headerSent = true;
   }
-  this._writeRaw(data, encoding);
+  return this._writeRaw(data, encoding);
 };
 
 OutgoingMessage.prototype._writeRaw = function(data, encoding) {
@@ -347,7 +347,6 @@ OutgoingMessage.prototype._writeRaw = function(data, encoding) {
 };
 
 OutgoingMessage.prototype._buffer = function (data, encoding) {
-  // Buffer
   if (data.length === 0) return;
 
   var length = this.output.length;

lib/net.js

@@ -665,7 +665,8 @@ Stream.prototype.write = function (data, encoding, fd) {
     }
 
     if (typeof data == 'string' &&
-        this._writeQueueEncoding.length &&
+        this._writeQueue.length &&
+        typeof this._writeQueue[this._writeQueue.length-1] === 'string' &&
         this._writeQueueEncoding[this._writeQueueEncoding.length-1] === encoding) {
       // optimization - concat onto last
       this._writeQueue[this._writeQueue.length-1] += data;