diff -r 4ebc2e2fb97c -r 71c04702a3d5 test/nashorn/script/basic/JDK-8026858.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/nashorn/script/basic/JDK-8026858.js	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2010, 2013, 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.
+ */
+
+/**
+ * JDK-8026858: Array length does not handle defined properties correctly
+ *
+ * @test
+ * @run
+ */
+
+var arr = [];
+
+Object.defineProperty(arr, "3", {value: 1 /* configurable: false */});
+
+if (arr[3] != 1) {
+    throw new Error("arr[3] not defined");
+}
+
+if (arr.length !== 4) {
+    throw new Error("Array length not updated to 4");
+}
+
+Object.defineProperty(arr, "5", {value: 1, configurable: true});
+
+if (arr[5] != 1) {
+    throw new Error("arr[5] not defined");
+}
+
+if (arr.length !== 6) {
+    throw new Error("Array length not updated to 4");
+}
+
+arr.length = 0;
+
+if (5 in arr) {
+    throw new Error("configurable element was not deleted");
+}
+
+if (arr[3] != 1) {
+    throw new Error("non-configurable element was deleted");
+}
+
+if (arr.length !== 4) {
+    throw new Error("Array length not set");
+}
+