Throw the right exceptions from setting elements in Array.prototype.concat

test/mjsunit/regress/regress-595319.js

+// Copyright 2016 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.
+
+// https://bugs.chromium.org/p/chromium/issues/detail?id=595319
+// Ensure exceptions are checked for by Array.prototype.concat from adding
+// an element, and that elements are added to array subclasses appropriately
+
+// If adding a property does throw, the exception is propagated
+class MyException extends Error { }
+class NoDefinePropertyArray extends Array {
+  constructor(...args) {
+    super(...args);
+    return new Proxy(this, {
+      defineProperty() { throw new MyException(); }
+    });
+  }
+}
+assertThrows(() => new NoDefinePropertyArray().concat([1]), MyException);
+
+// Ensure elements are added to the instance, rather than calling [[Set]].
+class ZeroGetterArray extends Array { get 0() {} };
+assertArrayEquals([1], new ZeroGetterArray().concat(1));
+
+// Frozen arrays lead to throwing
+
+class FrozenArray extends Array {
+  constructor(...args) { super(...args); Object.freeze(this); }
+}
+assertThrows(() => new FrozenArray().concat([1]), TypeError);
+
+// Non-configurable non-writable zero leads to throwing
+class ZeroFrozenArray extends Array {
+  constructor(...args) {
+    super(...args);
+    Object.defineProperty(this, 0, {value: 1});
+  }
+}
+assertThrows(() => new ZeroFrozenArray().concat([1]), TypeError);