Query param with comma produce multiple query params

Hi,

Client:

import java.net.URI;
import java.util.Map;

import feign.HeaderMap;
import feign.RequestLine;
import feign.Response;

public interface GenericFeignApi {
  @RequestLine("GET")
  Response get(URI uri, @HeaderMap Map<String, Object> headers);
}

Open feign 11.1 produces ?param=first&param=second&param=third

expected: ?param=first,second,third

#924 #922 - These issues are similar and got fixed by https://github.com/OpenFeign/feign/pull/930
but I am still experiencing it in OpenFeign 11.1

P.S. Currently I am able to get it work by url-encoding 'comma' in the query param before providing it to Feign as proposed in #924 #922

Thanks.

Start by reproducing the request from the GenericFeignApi example using @RequestLine, URI, and @HeaderMap, then trace the query-parameter serialization path. Compare the generated URL with the expected single comma-separated parameter and confirm the behavior with a regression test covering comma-containing values.