ES6: Remove __proto__ setter poison pill

test/mjsunit/proto-accessor.js

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-// Check that the __proto__ accessor is properly poisoned when extracted
-// from Object.prototype using the property descriptor.
 var desc = Object.getOwnPropertyDescriptor(Object.prototype, "__proto__");
 assertEquals("function", typeof desc.get);
 assertEquals("function", typeof desc.set);
 assertDoesNotThrow("desc.get.call({})");
-assertThrows("desc.set.call({})", TypeError);
+assertDoesNotThrow("desc.set.call({}, {})");
 
-// Check that any redefinition of the __proto__ accessor causes poising
-// to cease and the accessor to be extracted normally.
-Object.defineProperty(Object.prototype, "__proto__", { get:function(){} });
-desc = Object.getOwnPropertyDescriptor(Object.prototype, "__proto__");
-assertDoesNotThrow("desc.get.call({})");
-assertThrows("desc.set.call({})", TypeError);
+
+var obj = {};
+var obj2 = {};
+desc.set.call(obj, obj2);
+assertEquals(obj.__proto__, obj2);
+assertEquals(desc.get.call(obj), obj2);
+
+
+// Check that any redefinition of the __proto__ accessor works.

[rossberg, 2014/02/06 11:53:22]

Maybe add a test case that redefines the setter to undefined and assignment to
__proto__ throws accordingly.

[arv (Not doing code reviews), 2014/02/06 15:43:47]

Done.

+ Object.defineProperty(Object.prototype, "__proto__", { get:function() {

[rossberg, 2014/02/06 11:53:22]

Nit: weird indentation

[arv (Not doing code reviews), 2014/02/06 15:43:47]

Done.

+   return 42;
+ } });
+ assertEquals({}.__proto__, 42);
+ assertEquals(desc.get.call({}), Object.prototype);
+
+
+var desc2 = Object.getOwnPropertyDescriptor(Object.prototype, "__proto__");
+assertEquals(desc2.get.call({}), 42);
+assertDoesNotThrow("desc2.set.call({})");
+
+
 Object.defineProperty(Object.prototype, "__proto__", { set:function(x){} });
-desc = Object.getOwnPropertyDescriptor(Object.prototype, "__proto__");
-assertDoesNotThrow("desc.get.call({})");
-assertDoesNotThrow("desc.set.call({})");
+var desc3 = Object.getOwnPropertyDescriptor(Object.prototype, "__proto__");
+assertDoesNotThrow("desc3.get.call({})");
+assertDoesNotThrow("desc3.set.call({})");