http: fix XMLHttpRequest piped in a writable file stream hangs next request

Fixes #2263.

lib/http.js

@@ -136,6 +136,11 @@ var parsers = new FreeList('parsers', 1000, function() {
       parser.incoming.readable = false;
       parser.incoming.emit('end');
     }
+
+    if (parser.socket.readable) {
+      // force to read the next incoming message
+      parser.socket.resume();
+    }
   };
 
   return parser;

test/simple/test-http-pipe-fs.js

@@ -0,0 +1,68 @@
+// 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 fs = require('fs');
+var path = require('path');
+
+var file = path.join(common.tmpDir, 'http-pipe-fs-test.txt');
+var requests = 0;
+
+var server = http.createServer(function(req, res) {
+  ++requests;
+  var stream = fs.createWriteStream(file);
+  req.pipe(stream);
+  stream.on('close', function() {
+    res.writeHead(200);
+    res.end();
+  });
+}).listen(common.PORT, function() {
+  http.globalAgent.maxSockets = 1;
+
+  for (var i = 0; i < 2; ++i) {
+    (function(i) {
+      var req = http.request({
+        port: common.PORT,
+        method: 'POST',
+        headers: {
+          'Content-Length': 5
+        }
+      }, function(res) {
+        res.on('end', function() {
+          common.debug('res' + i + ' end');
+          if (i === 2) {
+            server.close();
+          }
+        });
+      });
+      req.on('socket', function(s) {
+        common.debug('req' + i + ' start');
+      });
+      req.end('12345');
+    }(i + 1));
+  }
+});
+
+process.on('exit', function() {
+  assert.equal(requests, 2);
+});