1 files changed, 26 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Array/prototype/lastIndexOf/15.4.4.15-5-21.js b/js/src/tests/test262/built-ins/Array/prototype/lastIndexOf/15.4.4.15-5-21.js
new file mode 100644
index 0000000000..135ca125b4
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Array/prototype/lastIndexOf/15.4.4.15-5-21.js
@@ -0,0 +1,26 @@
+// Copyright (c) 2012 Ecma International.  All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-array.prototype.lastindexof
+description: >
+    Array.prototype.lastIndexOf - value of 'fromIndex' which is an
+    Object, and has an own toString method
+---*/
+
+// objects inherit the default valueOf() method from Object
+// that simply returns itself. Since the default valueOf() method
+// does not return a primitive value, ES next tries to convert the object
+// to a number by calling its toString() method and converting the
+// resulting string to a number.
+var fromIndex = {
+  toString: function() {
+    return '2';
+  }
+};
+var targetObj = new RegExp();
+
+assert.sameValue([0, true, targetObj, 3, false].lastIndexOf(targetObj, fromIndex), 2, '[0, true, targetObj, 3, false].lastIndexOf(targetObj, fromIndex)');
+assert.sameValue([0, true, 3, targetObj, false].lastIndexOf(targetObj, fromIndex), -1, '[0, true, 3, targetObj, false].lastIndexOf(targetObj, fromIndex)');
+
+reportCompare(0, 0);