http: fix no dumping after maybeReadMore

When `maybeReadMore` kicks in on a first bytes of incoming data, the
`req.read(0)` will be invoked and the `req._consuming` will be set to
`true`. This seemingly harmless property leads to a dire consequences:
the server won't call `req._dump()` and the whole HTTP/1.1 pipeline will
hang (single connection).

PR-URL: #7211
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

lib/_http_incoming.js

@@ -20,6 +20,13 @@ exports.readStop = readStop;
 function IncomingMessage(socket) {
   Stream.Readable.call(this);
 
+  // Set this to `true` so that stream.Readable won't attempt to read more
+  // data on `IncomingMessage#push` (see `maybeReadMore` in
+  // `_stream_readable.js`). This is important for proper tracking of
+  // `IncomingMessage#_consuming` which is used to dump requests that users
+  // haven't attempted to read.
+  this._readableState.readingMore = true;
+
   this.socket = socket;
   this.connection = socket;
 
@@ -67,6 +74,8 @@ IncomingMessage.prototype.setTimeout = function(msecs, callback) {
 
 
 IncomingMessage.prototype.read = function(n) {
+  if (!this._consuming)
+    this._readableState.readingMore = false;
   this._consuming = true;
   this.read = Stream.Readable.prototype.read;
   return this.read(n);

test/parallel/test-http-no-read-no-dump.js

@@ -0,0 +1,51 @@
+'use strict';
+const common = require('../common');
+const http = require('http');
+
+let onPause = null;
+
+const server = http.createServer((req, res) => {
+  if (req.method === 'GET')
+    return res.end();
+
+  res.writeHead(200);
+  res.flushHeaders();
+
+  req.connection.on('pause', () => {
+    res.end();
+    onPause();
+  });
+}).listen(common.PORT, common.mustCall(() => {
+  const agent = new http.Agent({
+    maxSockets: 1,
+    keepAlive: true
+  });
+
+  const post = http.request({
+    agent: agent,
+    method: 'POST',
+    port: common.PORT,
+  }, common.mustCall((res) => {
+    res.resume();
+
+    post.write(Buffer.alloc(16 * 1024).fill('X'));
+    onPause = () => {
+      post.end('something');
+    };
+  }));
+
+  /* What happens here is that the server `end`s the response before we send
+   * `something`, and the client thought that this is a green light for sending
+   * next GET request
+   */
+  post.write('initial');
+
+  http.request({
+    agent: agent,
+    method: 'GET',
+    port: common.PORT,
+  }, common.mustCall((res) => {
+    server.close();
+    res.connection.end();
+  })).end();
+}));