http: write() after end() emits an error.

When calling write() after end() has been called on an OutgoingMessage,
an error is emitted and the write's callback is called with an instance
of Error.

Fix #7477.

Reviewed-By: Fedor Indutny <fedor@indutny.com>

lib/_http_outgoing.js

@@ -403,6 +403,18 @@ Object.defineProperty(OutgoingMessage.prototype, 'headersSent', {
 
 
 OutgoingMessage.prototype.write = function(chunk, encoding, callback) {
+  var self = this;
+
+  if (this.finished) {
+    var err = new Error('write after end');
+    process.nextTick(function() {
+      self.emit('error', err);
+      if (callback) callback(err);
+    });
+
+    return true;
+  }
+
   if (!this._header) {
     this._implicitHeader();
   }

test/simple/test-http-res-write-after-end.js

@@ -0,0 +1,49 @@
+// 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');
+
+var responseError;
+
+var server = http.Server(function(req, res) {
+  res.on('error', function onResError(err) {
+    responseError = err;
+  });
+
+  res.write('This should write.');
+  res.end();
+
+  var r = res.write('This should raise an error.');
+  assert.equal(r, true, 'write after end should return true');
+});
+
+server.listen(common.PORT, function() {
+  var req = http.get({port: common.PORT}, function(res) {
+    server.close();
+  });
+});
+
+process.on('exit', function onProcessExit(code) {
+  assert(responseError, 'response should have emitted error');
+  assert.equal(responseError.message, 'write after end');
+});