JCLOUDS-1322: Remove Expect header for requests with empty body

Signed-off-by: Chaithanya Ganta <ganta@adobe.com>

apis/s3/src/test/java/org/jclouds/s3/S3ClientMockTest.java

@@ -20,6 +20,7 @@ import static com.google.common.net.HttpHeaders.CONTENT_LENGTH;
 import static com.google.common.net.HttpHeaders.ETAG;
 import static com.google.common.net.HttpHeaders.EXPECT;
 import static com.google.common.util.concurrent.MoreExecutors.sameThreadExecutor;
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.jclouds.Constants.PROPERTY_MAX_RETRIES;
 import static org.testng.Assert.assertEquals;
 
@@ -73,7 +74,7 @@ public class S3ClientMockTest {
       RecordedRequest request = server.takeRequest();
       assertEquals(request.getRequestLine(), "PUT /bucket/object HTTP/1.1");
       assertEquals(request.getHeaders(CONTENT_LENGTH), ImmutableList.of("0"));
-      assertEquals(request.getHeaders(EXPECT), ImmutableList.of("100-continue"));
+      assertThat(request.getHeaders(EXPECT)).isEmpty();
       server.shutdown();
    }
 

core/src/main/java/org/jclouds/rest/internal/RestAnnotationProcessor.java

@@ -357,6 +357,9 @@ public class RestAnnotationProcessor implements Function<Invocation, HttpRequest
       if (request.getPayload() != null) {
          contentMetadataCodec.fromHeaders(request.getPayload().getContentMetadata(), headers);
       }
+
+      request = stripExpectHeaderIfContentZero(request);
+
       utils.checkRequestHasRequiredProperties(request);
       return request;
    }
@@ -779,6 +782,18 @@ public class RestAnnotationProcessor implements Function<Invocation, HttpRequest
       return parts.build();
    }
 
+   private static GeneratedHttpRequest stripExpectHeaderIfContentZero(GeneratedHttpRequest request) {
+      boolean isBodyEmpty = true;
+      if (request.getPayload() != null) {
+         Long length = request.getPayload().getContentMetadata().getContentLength();
+         isBodyEmpty = length != null && length == 0;
+      }
+      if (isBodyEmpty) {
+         request = request.toBuilder().removeHeader("Expect").build();
+      }
+      return request;
+   }
+
    private boolean isEncodedUsed(Invocation invocation) {
       return !parametersWithAnnotation(invocation.getInvokable(), Encoded.class).isEmpty();
    }

core/src/test/java/org/jclouds/rest/internal/RestAnnotationProcessorTest.java

@@ -21,6 +21,7 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import static javax.ws.rs.core.MediaType.APPLICATION_JSON;
 import static javax.ws.rs.core.MediaType.APPLICATION_XML;
 import static org.assertj.core.api.Assertions.failBecauseExceptionWasNotThrown;
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.jclouds.io.Payloads.newInputStreamPayload;
 import static org.jclouds.io.Payloads.newStringPayload;
 import static org.jclouds.providers.AnonymousProviderMetadata.forApiOnEndpoint;
@@ -1559,6 +1560,17 @@ public class RestAnnotationProcessorTest extends BaseRestApiTest {
       assertEquals(request.getFilters().get(1).getClass(), ConnectionCloseHeader.class);
    }
 
+   @Test
+   public void testZeroContentStripExpectHeader() {
+      Invokable<?, ?> method = method(TestRequestFilter.class, "post");
+      Invocation invocation = Invocation.create(method,
+              ImmutableList.<Object>of(HttpRequest.builder().method("POST").endpoint("http://localhost")
+                      .payload(new byte[0]).addHeader(HttpHeaders.EXPECT, "100-Continue")
+                      .build()));
+      GeneratedHttpRequest request = processor.apply(invocation);
+      assertThat(request.getFirstHeaderOrNull(HttpHeaders.EXPECT)).isNull();
+   }
+
    public static class TestEncoding {
       @GET
       @Path("/{path1}/{path2}")