1 files changed, 29 insertions, 0 deletions
diff --git a/deps/v8/test/mjsunit/regress/regress-961709-classes.js b/deps/v8/test/mjsunit/regress/regress-961709-classes.js
new file mode 100644
index 0000000000..a574321774
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/regress-961709-classes.js
@@ -0,0 +1,29 @@
+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+
+// Flags: --allow-natives-syntax
+
+function foo(a, i) {
+  a[i] = 1;
+  return a[i];
+}
+
+class MyArray extends (class C extends Array {
+}){};
+
+o = new MyArray;
+
+%EnsureFeedbackVectorForFunction(foo);
+// initialize IC
+assertEquals(1, foo(o, 0));
+assertEquals(1, foo(o, 1));
+
+// Change prototype
+o.__proto__.__proto__ = new Int32Array(2);
+
+
+// Check it still works
+assertEquals(undefined, foo(o, 2));
+assertEquals(undefined, foo(o, 2));