• Version: v14.17.0
• Platform: OS X
• Subsystem: http

What steps will reproduce the bug?

Run the snippet below (from How do I create a HTTP server):

const http = require('http'); const requestListener = function (req, res) { res.writeHead(200); res.end('Hello, World!'); } const server = http.createServer(requestListener); server.listen(8080);

And call the server with the following command:

curl -i localhost:8080 -X HEAD 

Running the server on v14.16.1, the curl command will return 0 with the following output:

$ curl -i localhost:8080 -X HEAD Warning: Setting custom HTTP method to HEAD with -X/--request may not work the Warning: way you want. Consider using -I/--head instead. HTTP/1.1 200 OK Date: Fri, 04 Jun 2021 04:15:27 GMT Connection: keep-alive Keep-Alive: timeout=5

Running the server on v14.17.0, the curl command will exit with code 18 and the following error:

$ curl -i localhost:8080 -X HEAD Warning: Setting custom HTTP method to HEAD with -X/--request may not work the Warning: way you want. Consider using -I/--head instead. HTTP/1.1 200 OK Date: Fri, 04 Jun 2021 04:16:58 GMT Connection: keep-alive Keep-Alive: timeout=5 Transfer-Encoding: chunked curl: (18) transfer closed with outstanding read data remaining

How often does it reproduce? Is there a required condition?

Always

What is the expected behavior?

Within a major, no header that could potentially destructively affects HTTP clients behavior should be introduced.

What do you see instead?

Transfer-Encoding: chunked is introduced, causing curl to exit with an error code.

Additional information

I noticed this error on this Restify test recently. I'm not entirely sure if this should be considered a breaking change, but it seems like one. I couldn't determine which commit introduced it yet though.

cc @nodejs/http (and @nodejs/tsc @nodejs/lts for visibility)