body of DELETE request is not send by org.springframework.http.client.JdkClientHttpRequest

[damgu]

Hello,

Context
I'am using Spring Cloud Gateway to forward requests between 2 applications.
After upgrading to Spring Boot 3.5.x and Spring MVC 6.2.8, there is an issue on DELETE requests with body.
The body is not send anymore.

Issue
org.springframework.http.client.JdkClientHttpRequest don't send body when the request is a DELETE request

	private HttpRequest buildRequest(HttpHeaders headers, @Nullable Body body) {
		HttpRequest.Builder builder = HttpRequest.newBuilder().uri(this.uri);

		headers.forEach((headerName, headerValues) -> {
			if (!DISALLOWED_HEADERS.contains(headerName.toLowerCase(Locale.ROOT))) {
				for (String headerValue : headerValues) {
					builder.header(headerName, headerValue);
				}
			}
		});

		switch (this.method.name()) {
			case "GET" :
				builder.GET();
				break;
			case "DELETE" :
				builder.DELETE();
				break;
			default :
				builder.method(this.method.name(), bodyPublisher(headers, body));
		}
		return builder.build();
	}

Correction
Just delete the case "DELETE"

DELETE method may have a body
https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Methods/DELETE

I think is wrong to not send it.
Other implementations of ClientHttpRequest send the body without any check (org.springframework.http.client.JettyClientHttpRequest, org.springframework.http.client.SimpleClientHttpRequest,...)

Thank you

[bclozel]

Duplicates #35068