http: fix missing close event on aborted response

lib/_http_outgoing.js

@@ -62,6 +62,7 @@ function OutgoingMessage() {
   this._trailer = '';
 
   this.finished = false;
+  this._finishOrCloseEmitted = false;
   this._hangupClose = false;
   this._headerSent = false;
 
@@ -517,6 +518,8 @@ OutgoingMessage.prototype.end = function(data, encoding, callback) {
 
   var self = this;
   function finish() {
+    if (self._finishOrCloseEmitted) return;
+    self._finishOrCloseEmitted = true;
     self.emit('finish');
   }
 

lib/_http_server.js

@@ -122,7 +122,10 @@ function onServerResponseClose() {
   // Ergo, we need to deal with stale 'close' events and handle the case
   // where the ServerResponse object has already been deconstructed.
   // Fortunately, that requires only a single if check. :-)
-  if (this._httpMessage) this._httpMessage.emit('close');
+  if (this._httpMessage && !this._httpMessage._finishOrCloseEmitted) {
+    this._httpMessage._finishOrCloseEmitted = true;
+    this._httpMessage.emit('close');
+  }
 }
 
 ServerResponse.prototype.assignSocket = function(socket) {
@@ -137,6 +140,13 @@ ServerResponse.prototype.assignSocket = function(socket) {
 
 ServerResponse.prototype.detachSocket = function(socket) {
   assert(socket._httpMessage === this);
+  if (socket.destroyed && !socket._httpMessage._finishOrCloseEmitted) {
+    var httpMessage = socket._httpMessage;
+    httpMessage._finishOrCloseEmitted = true;
+    setImmediate(function() {
+      httpMessage.emit('close');
+    });
+  }
   socket.removeListener('close', onServerResponseClose);
   socket._httpMessage = null;
   this.socket = this.connection = null;

test/parallel/test-http-response-close-event-race.js

@@ -0,0 +1,88 @@
+var common = require('../common');
+var assert = require('assert');
+var http = require('http');
+
+var clientRequest = null;
+var serverResponseFinishedOrClosed = 0;
+var testTickCount = 3;
+
+var server = http.createServer(function (req, res) {
+  console.log('server: request');
+
+  res.on('finish', function () {
+    console.log('server: response finish');
+    serverResponseFinishedOrClosed++;
+  });
+  res.on('close', function () {
+    console.log('server: response close');
+    serverResponseFinishedOrClosed++;
+  });
+
+  console.log('client: aborting request');
+  clientRequest.abort();
+
+  var ticks = 0;
+  function tick() {
+    console.log('server: tick ' + ticks + (req.connection.destroyed ? ' (connection destroyed!)' : ''));
+
+    if (ticks < testTickCount) {
+      ticks++;
+      setImmediate(tick);
+    } else {
+      sendResponse();
+    }
+  }
+  tick();
+
+  function sendResponse() {
+    console.log('server: sending response');
+    res.writeHead(200, {'Content-Type': 'text/plain'});
+    res.end('Response\n');
+    console.log('server: res.end() returned');
+
+    handleResponseEnd();
+  }
+});
+
+server.on('listening', function () {
+  console.log('server: listening on port ' + common.PORT);
+  console.log('-----------------------------------------------------');
+  startRequest();
+});
+
+server.on('connection', function (connection) {
+  console.log('server: connection');
+  connection.on('close', function () { console.log('server: connection close'); });
+});
+
+server.on('close', function () {
+  console.log('server: close');
+});
+
+server.listen(common.PORT);
+
+function startRequest() {
+  console.log('client: starting request - testing with ' + testTickCount + ' ticks after abort()');
+  serverResponseFinishedOrClosed = 0;
+
+  var options = {port: common.PORT, path: '/'};
+  clientRequest = http.get(options, function () {});
+  clientRequest.on('error', function () {});
+}
+
+function handleResponseEnd() {
+  setImmediate(function () {
+    setImmediate(function () {
+      assert.equal(serverResponseFinishedOrClosed, 1, 'Expected either one "finish" or one "close" event on the response for aborted connections (got ' + serverResponseFinishedOrClosed + ')');
+      console.log('server: ended request with correct finish/close event');
+      console.log('-----------------------------------------------------');
+
+      if (testTickCount > 0) {
+        testTickCount--;
+        startRequest();
+      } else {
+        server.close();
+      }
+    });
+  });
+}