Properly respond to HEAD during end(body) hot path

During write(), _hasBody is checked to make sure a body
is allowed -- this is now also checked during end(body)
when write() isn't used.

Concise final chunk for HEAD req's res.end(data).

Instead of simply clearing data, check _hasBody
earlier to avoid sending cruft when chunkedEncoding
is used.

Fixes #1291.

lib/http.js

@@ -652,6 +652,12 @@ OutgoingMessage.prototype.end = function(data, encoding) {
     this._implicitHeader();
   }
 
+  if (data && !this._hasBody) {
+    console.error('This type of response MUST NOT have a body. ' +
+                  'Ignoring data passed to end().');
+    data = false;
+  }
+
   var ret;
 
   var hot = this._headerSent === false &&
@@ -667,6 +673,7 @@ OutgoingMessage.prototype.end = function(data, encoding) {
     //   res.writeHead();
     //   res.end(blah);
     // HACKY.
+
     if (this.chunkedEncoding) {
       var l = Buffer.byteLength(data, encoding).toString(16);
       ret = this.connection.write(this._header + l + CRLF +

test/simple/test-http-head-response-has-no-body-end.js

@@ -0,0 +1,55 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+var common = require('../common');
+var assert = require('assert');
+
+var http = require('http');
+
+// This test is to make sure that when the HTTP server
+// responds to a HEAD request with data to res.end,
+// it does not send any body.
+
+var server = http.createServer(function(req, res) {
+  res.writeHead(200);
+  res.end('FAIL'); // broken: sends FAIL from hot path.
+});
+server.listen(common.PORT);
+
+var responseComplete = false;
+
+server.addListener('listening', function() {
+  var req = http.createClient(common.PORT).request('HEAD', '/');
+  common.error('req');
+  req.end();
+  req.addListener('response', function(res) {
+    common.error('response');
+    res.addListener('end', function() {
+      common.error('response end');
+      server.close();
+      responseComplete = true;
+    });
+  });
+});
+
+process.addListener('exit', function() {
+  assert.ok(responseComplete);
+});