--- /dev/null	2018-09-19 19:35:41.000000000 +0530
+++ new/test/jdk/com/sun/tools/jextract/RedundantDeclsTest.java	2018-09-19 19:35:40.000000000 +0530
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import org.testng.annotations.Test;
+
+import java.nio.file.Path;
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertNotNull;
+import static org.testng.Assert.assertTrue;
+
+/*
+ * @test
+ * @bug 8210911
+ * @summary jextract does not handle redundant forward, backward declarations of struct, union, enum properly
+ * @modules jdk.jextract
+ * @build JextractToolRunner
+ * @run testng RedundantDeclsTest
+ */
+public class RedundantDeclsTest extends JextractToolRunner {
+    @Test
+    public void redundantDecls() {
+        Path clzPath = getOutputFilePath("RedundentDecls.jar");
+        checkSuccess(null,"-o", clzPath.toString(),
+                getInputFilePath("redundantDecls.h").toString());
+        Class<?> headerCls = loadClass("redundantDecls", clzPath);
+        Class<?>[] inners = headerCls.getDeclaredClasses();
+        assertEquals(inners.length, 4);
+
+        Class<?> pointStruct = findClass(inners, "Point");
+        assertNotNull(findStructFieldGet(pointStruct, "i"));
+        assertNotNull(findStructFieldGet(pointStruct, "j"));
+
+        Class<?> point3DStruct = findClass(inners, "Point3D");
+        assertNotNull(findStructFieldGet(point3DStruct, "i"));
+        assertNotNull(findStructFieldGet(point3DStruct, "j"));
+        assertNotNull(findStructFieldGet(point3DStruct, "k"));
+
+        checkIntField(headerCls, "R", 0);
+        checkIntField(headerCls, "G", 1);
+        checkIntField(headerCls, "B", 2);
+
+        checkIntField(headerCls, "C", 0);
+        checkIntField(headerCls, "M", 1);
+        checkIntField(headerCls, "Y", 2);
+
+        Class<?> rgbColor = findClass(inners, "RGBColor");
+        assertNotNull(rgbColor);
+        assertTrue(rgbColor.isAnnotation());
+
+        Class<?> cmyColor = findClass(inners, "CMYColor");
+        assertNotNull(cmyColor);
+        assertTrue(cmyColor.isAnnotation());
+
+        deleteFile(clzPath);
+    }
+}