Partially fix semantics of Array.push()

test/mjsunit/array-push5.js

Index: test/mjsunit/array-push5.js
diff --git a/test/mjsunit/array-push5.js b/test/mjsunit/array-push5.js
new file mode 100644
index 0000000000000000000000000000000000000000..83339a21e0eccad2467782c7ff72ec1430e565c7
--- /dev/null
+++ b/test/mjsunit/array-push5.js
@@ -0,0 +1,42 @@
+// Copyright 2014 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
+
+var v = 0;
+
+// Test that elements setters/getters on prototype chain set after the fact are
+// property detected and don't lead to overzealous optimization.
+var my_array_proto = {};
+my_array_proto.__proto__ = [].__proto__;
+
+function push_wrapper_2(array, value) {
+  array.push(value);
+}
+array = [];
+array.__proto__ = my_array_proto;
+push_wrapper_2(array, 66);
+assertEquals(1, array.length);
+assertEquals(0, v);
+assertEquals(66, array[0]);
+push_wrapper_2(array, 77);
+assertEquals(2, array.length);
+assertEquals(0, v);
+assertEquals(77, array[1]);
+%OptimizeFunctionOnNextCall(push_wrapper_2);
+push_wrapper_2(array, 88);
+assertEquals(3, array.length);
+assertEquals(0, v);
+assertEquals(88, array[2]);
+assertOptimized(push_wrapper_2);
+// Defining accessor should deopt optimized push.
+Object.defineProperty(my_array_proto, "3", {
+get: function() { return "get " + v; },
+set: function(value) { v += value; }
+});
+assertUnoptimized(push_wrapper_2);
+push_wrapper_2(array, 99);
+assertEquals(4, array.length);
+assertEquals(99, v);
+assertEquals("get 99", array[3]);