http server returns 400 status code for valid request on keepalive connection after an error was caught by a domain

[dragosnicolae]

• Version: 10.13.0
• Platform: Linux themachine.novalocal 3.10.0-862.14.4.el7.x86_64 deps: update openssl to 1.0.1j #1 SMP Wed Sep 26 15:12:11 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

If an error is thrown while handling a request and then it is caught by an error domain, the second request coming on the same connection is not parsed correctly and the server returns 400 Bad Request.

I managed to reproduce this using a simple example. Server code:

'use strict';

var ed = require('domain');
var http = require('http');

var count = 0;

var server = http.createServer(function(request, response) {
	var d = ed.createDomain();
	d.on('error', function() {
		console.log("request", count++);
		response.statusCode = 500;
		response.end();
	}); 
	
	d.enter();
	throw new Error("Something wrong happened.");
	d.exit();
});
server.listen(8092, "127.0.0.1", function() {
	console.log("connected");
});

Make the requests:

# curl -v 'http://127.0.0.1:8092' 'http://127.0.0.1:8092'
* About to connect() to 127.0.0.1 port 8092 (#0)
*   Trying 127.0.0.1...
* Connected to 127.0.0.1 (127.0.0.1) port 8092 (#0)
> GET / HTTP/1.1
> User-Agent: curl/7.29.0
> Host: 127.0.0.1:8092
> Accept: */*
>
< HTTP/1.1 500 Internal Server Error
< Date: Tue, 11 Dec 2018 09:49:43 GMT
< Connection: keep-alive
< Content-Length: 0
<
* Connection #0 to host 127.0.0.1 left intact
* Found bundle for host 127.0.0.1: 0x2283ec0
* Re-using existing connection! (#0) with host 127.0.0.1
* Connected to 127.0.0.1 (127.0.0.1) port 8092 (#0)
> GET / HTTP/1.1
> User-Agent: curl/7.29.0
> Host: 127.0.0.1:8092
> Accept: */*
>
< HTTP/1.1 400 Bad Request
* no chunk, no close, no size. Assume close to signal end
<
* Closing connection 0

From what I found, the parser returns a HPE_CB_headers_complete error code. Most probably, the parser's internal state gets messed up or does not get to update when the error is thrown.

[dragosnicolae]

Tested on node 8.11.3 and this does not happen, both requests end with 500 status code.

[bnoordhuis]

It sounds like #25456 may be a duplicate of this issue, or at least is related.

[BridgeAR]

This is still reproducible on master. Seems like this was fixed on v8.x only.

[BridgeAR]

@misterdjules PTAL. I think you might have a fix for this.

[mmomtchev]

Still reproducible on Node 12 but not on Node 14/master

[BethGriggs]

I believe this was fixed in Node.js v12.19.0 (#35401)