HttpServer doesn't respect chunked transfer coding when other codings are present

[nex3]

If I write:

import 'dart:convert';
import 'dart:io';

main() async {
  var server = await HttpServer.bind('127.0.0.1', 8080);
  await for (var request in server) {
    request.response.headers.set('transfer-encoding', 'gzip chunked');
    request.response.add(GZIP.encoder.convert(UTF8.encode('foo')));
    request.response.close();
  }
}

And I make a GET / request, I get back:

HTTP/1.1 200 OK
content-type: text/plain; charset=utf-8
x-frame-options: SAMEORIGIN
x-xss-protection: 1; mode=block
transfer-encoding: gzip chunked
x-content-type-options: nosniff

K��!es�

I'd expect:

HTTP/1.1 200 OK
content-type: text/plain; charset=utf-8
x-frame-options: SAMEORIGIN
x-xss-protection: 1; mode=block
transfer-encoding: gzip chunked
x-content-type-options: nosniff

17
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0

Normally the server will apply the chunked transfer encoding based on the Transfer-Encoding header, but in this case it's not doing so. And, since there's no explicit way to tell the server whether or not to apply a chunked encoding, there's not really a good workaround here other than manually re-implementing chunked encoding and specifically only applying that implementation if there are multiple encodings specified.