Revert "Do not set 0 Content-Length header in BufferingClientHttpRequestFactory"

This reverts commit b3a4567.

See gh-32650

Author: bclozel

spring-web/src/main/java/org/springframework/http/client/AbstractBufferingClientHttpRequest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -42,7 +42,7 @@ protected OutputStream getBodyInternal(HttpHeaders headers) throws IOException {
 	@Override
 	protected ClientHttpResponse executeInternal(HttpHeaders headers) throws IOException {
 		byte[] bytes = this.bufferedOutput.toByteArrayUnsafe();
-		if (bytes.length > 0 && headers.getContentLength() < 0) {
+		if (headers.getContentLength() < 0) {
 			headers.setContentLength(bytes.length);
 		}
 		ClientHttpResponse result = executeInternal(headers, bytes);

spring-web/src/test/java/org/springframework/http/client/AbstractMockWebServerTests.java

@@ -106,10 +106,6 @@ else if(request.getPath().startsWith("/methods/")) {
 					assertThat(request.getMethod()).isEqualTo(expectedMethod);
 					return new MockResponse();
 				}
-				else if(request.getPath().startsWith("/header/")) {
-					String headerName = request.getPath().replace("/header/","");
-					return new MockResponse().setBody(headerName + ":" + request.getHeader(headerName)).setResponseCode(200);
-				}
 				return new MockResponse().setResponseCode(404);
 			}
 			catch (Throwable exc) {

spring-web/src/test/java/org/springframework/http/client/BufferingClientHttpRequestFactoryTests.java

@@ -16,7 +16,6 @@
 
 package org.springframework.http.client;
 
-import java.io.InputStreamReader;
 import java.net.URI;
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
@@ -50,7 +49,12 @@ void repeatableRead() throws Exception {
 		FileCopyUtils.copy(body, request.getBody());
 		try (ClientHttpResponse response = request.execute()) {
 			assertThat(response.getStatusCode()).as("Invalid status code").isEqualTo(HttpStatus.OK);
+			assertThat(response.getStatusCode()).as("Invalid status code").isEqualTo(HttpStatus.OK);
+
+			assertThat(response.getHeaders().containsKey(headerName)).as("Header not found").isTrue();
 			assertThat(response.getHeaders().containsKey(headerName)).as("Header not found").isTrue();
+
+			assertThat(response.getHeaders().get(headerName)).as("Header value not found").isEqualTo(Arrays.asList(headerValue1, headerValue2));
 			assertThat(response.getHeaders().get(headerName)).as("Header value not found").isEqualTo(Arrays.asList(headerValue1, headerValue2));
 
 			byte[] result = FileCopyUtils.copyToByteArray(response.getBody());
@@ -60,14 +64,4 @@ void repeatableRead() throws Exception {
 		}
 	}
 
-	@Test
-	void shouldNotSetContentLengthWhenEmptyBody() throws Exception {
-		ClientHttpRequest request = factory.createRequest(URI.create(baseUrl + "/header/Content-Length"), HttpMethod.POST);
-		try (ClientHttpResponse response = request.execute()) {
-			assertThat(response.getStatusCode()).as("Invalid status code").isEqualTo(HttpStatus.OK);
-			String result = FileCopyUtils.copyToString(new InputStreamReader(response.getBody()));
-			assertThat(result).as("Invalid body").isEqualTo("Content-Length:null");
-		}
-	}
-
 }