Response.hasEntity to return true if buffered after readEntity

core-client/src/test/java/org/glassfish/jersey/client/ClientResponseTest.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2020 Oracle and/or its affiliates. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0, which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the
+ * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
+ * version 2 with the GNU Classpath Exception, which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ */
+
+package org.glassfish.jersey.client;
+
+import org.glassfish.jersey.message.internal.InboundMessageContext;
+import org.junit.Assert;
+import org.junit.Test;
+
+import javax.ws.rs.client.ClientBuilder;
+import javax.ws.rs.client.ClientRequestFilter;
+import javax.ws.rs.core.Response;
+import javax.ws.rs.ext.ReaderInterceptor;
+import java.io.InputStream;
+
+public class ClientResponseTest {
+
+    @Test
+    public void testHasEntityWhenNoEntity() {
+        final InboundMessageContext inboundMessageContext = new InboundMessageContext(new ClientConfig()) {
+            @Override
+            protected Iterable<ReaderInterceptor> getReaderInterceptors() {
+                return null;
+            }
+        };
+
+        Assert.assertFalse(inboundMessageContext.hasEntity());
+
+        inboundMessageContext.bufferEntity();
+        Assert.assertFalse(inboundMessageContext.hasEntity());
+    }
+
+    @Test
+    public void testHasEntity() {
+        final ClientRequestFilter abortFilter = requestContext -> requestContext.abortWith(Response.ok("hello").build());
+        try (Response r = ClientBuilder.newClient().register(abortFilter).target("http://localhost:8080").request().get()) {
+            Assert.assertTrue(r.hasEntity());
+
+            r.bufferEntity();
+            Assert.assertTrue(r.hasEntity());
+
+            final String s = r.readEntity(String.class);
+            Assert.assertTrue(r.hasEntity());
+
+            final InputStream bufferedEntityStream = r.readEntity(InputStream.class);
+            Assert.assertNotNull(bufferedEntityStream);
+            Assert.assertTrue(r.hasEntity());
+        }
+    }
+}

core-common/src/main/java/org/glassfish/jersey/message/internal/InboundMessageContext.java

@@ -780,7 +780,7 @@ public boolean hasEntity() {
         entityContent.ensureNotClosed();
 
         try {
-            return !entityContent.isEmpty();
+            return entityContent.isBuffered() || !entityContent.isEmpty();
         } catch (IllegalStateException ex) {
             // input stream has been closed.
             return false;