http: fix handling of HTTP upgrades with bodies

Previously, we ignored all indicators of the body (content-length or
transfer-encoding headers) and treated any information following
the headers as part of the upgraded stream. We now fully process the
requests bodies as normal instead.

Author: pimterry

lib/_http_server.js

@@ -1078,8 +1078,9 @@ function parserOnIncoming(server, socket, state, req, keepAlive) {
   if (req.upgrade) {
     req.upgrade = req.method === 'CONNECT' ||
                   !!server.shouldUpgradeCallback(req);
-    if (req.upgrade)
-      return 2;
+    if (req.upgrade) {
+      return 0;
+    }
   }
 
   state.incoming.push(req);

test/parallel/test-http-upgrade-server-with-body.js

@@ -0,0 +1,46 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const http = require('http');
+const net = require('net');
+
+const server = http.createServer();
+
+server.on('request', common.mustNotCall());
+
+server.on('upgrade', function(req, socket, upgradeHead) {
+  let reqBody = '';
+  req.on('data', common.mustCall((str) => { reqBody += str; }));
+  req.on('end', common.mustCall(() => {
+    assert.strictEqual(reqBody, 'request body');
+    socket.end();
+  }));
+
+  assert.strictEqual(upgradeHead.toString(), 'upgrade head');
+});
+
+server.listen(0, function() {
+  const conn = net.createConnection(this.address().port);
+  conn.setEncoding('utf8');
+
+  conn.on('connect', function() {
+    conn.write(
+      'POST / HTTP/1.1\r\n' +
+      'Upgrade: WebSocket\r\n' +
+      'Connection: Upgrade\r\n' +
+      'Content-Length: 12\r\n' +
+      '\r\n' +
+      'request body' +
+      'upgrade head'
+    );
+  });
+
+  conn.on('end', function() {
+    conn.end();
+  });
+
+  conn.on('close', function() {
+    server.close();
+  });
+});