Spring WebClient with reactor-netty fails to send multiple request cookies

WebClient only sends the first cookie to the server when multiple cookies are set in the request.

See the following test case for repro: https://github.com/spring-projects/spring-framework/blob/df32d7f026941fff2dc376d62cceb3424cd34d1f/spring-webflux/src/test/java/org/springframework/web/reactive/function/client/WebClientIntegrationTests.java#L625-L654

Reactor-netty implementation needed to be excluded to make the test pass: https://github.com/spring-projects/spring-framework/blob/df32d7f026941fff2dc376d62cceb3424cd34d1f/spring-webflux/src/test/java/org/springframework/web/reactive/function/client/WebClientIntegrationTests.java#L629-L632

Comment From: rstoyanchev

It sends all of them:

assertThat(request.getHeaders().toMultimap().get(HttpHeaders.COOKIE))
        .isEqualTo(Arrays.asList("testkey=testvalue", "testkey2=testvalue2"));