http: flush stored header

lib/_http_outgoing.js

@@ -636,10 +636,11 @@ OutgoingMessage.prototype._flush = function() {
 
 OutgoingMessage.prototype.flushHeaders = function() {
  if (!this._header) {
- // Force-flush the headers.
  this._implicitHeader();
- this._send('');
  }
+
+ // Force-flush the headers.
+ this._send('');
 };
 
 OutgoingMessage.prototype.flush = util.deprecate(function() {

test/parallel/test-http-flush-headers.js

@@ -5,7 +5,7 @@ const http = require('http');
 
 const server = http.createServer();
 server.on('request', function(req, res) {
- assert(req.headers['foo'], 'bar');
+ assert.equal(req.headers['foo'], 'bar');
  res.end('ok');
  server.close();
 });

test/parallel/test-http-flush-response-headers.js

@@ -0,0 +1,27 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const http = require('http');
+
+const server = http.createServer();
+
+server.on('request', function(req, res) {
+ res.writeHead(200, {'foo': 'bar'});
+ res.flushHeaders();
+ res.flushHeaders(); // Should be idempotent.
+});
+server.listen(common.PORT, common.localhostIPv4, function() {
+ var req = http.request({
+ method: 'GET',
+ host: common.localhostIPv4,
+ port: common.PORT,
+ }, onResponse);
+
+ req.end();
+
+ function onResponse(res) {
+ assert.equal(res.headers['foo'], 'bar');
+ res.destroy();
+ server.close();
+ }
+});