SPR-8809 - RestTemplate headers not sent when bufferRequestBody is false

org.springframework.web/src/main/java/org/springframework/http/client/InterceptingClientHttpRequest.java

@@ -85,9 +85,8 @@ class InterceptingClientHttpRequest extends AbstractBufferingClientHttpRequest {
 
 				delegate.getHeaders().putAll(request.getHeaders());
 
-				if (body.length > 0) {
 				FileCopyUtils.copy(body, delegate.getBody());
-				}
+
 				return delegate.execute();
 			}
 		}

org.springframework.web/src/test/java/org/springframework/http/client/StreamingSimpleHttpRequestFactoryTests.java

@@ -16,14 +16,18 @@
 
 package org.springframework.http.client;
 
+import java.io.IOException;
 import java.io.OutputStream;
 import java.net.URI;
+import java.util.Collections;
 import java.util.Random;
 
 import org.junit.Ignore;
 import org.junit.Test;
 
+import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
+import org.springframework.http.HttpRequest;
 import org.springframework.http.HttpStatus;
 
 import static org.junit.Assert.*;
@@ -37,6 +41,36 @@ public class StreamingSimpleHttpRequestFactoryTests extends AbstractHttpRequestF
 		return factory;
 	}
 
+	// SPR-8809
+	@Test
+	public void interceptor() throws Exception {
+		final String headerName = "MyHeader";
+		final String headerValue = "MyValue";
+		ClientHttpRequestInterceptor interceptor = new ClientHttpRequestInterceptor() {
+			public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution)
+					throws IOException {
+				request.getHeaders().add(headerName, headerValue);
+				return execution.execute(request, body);
+			}
+		};
+		InterceptingClientHttpRequestFactory factory = new InterceptingClientHttpRequestFactory(createRequestFactory(),
+				Collections.singletonList(interceptor));
+
+		ClientHttpResponse response = null;
+		try {
+			ClientHttpRequest request = factory.createRequest(new URI(baseUrl + "/echo"), HttpMethod.POST);
+			response = request.execute();
+			assertEquals("Invalid response status", HttpStatus.OK, response.getStatusCode());
+			HttpHeaders responseHeaders = response.getHeaders();
+			assertEquals("Custom header invalid", headerValue, responseHeaders.getFirst(headerName));
+		}
+		finally {
+			if (response != null) {
+				response.close();
+			}
+		}
+	}
+
 	@Test
 	@Ignore
 	public void largeFileUpload() throws Exception {