1073808 - Array.of overwrites non-configurable properties

Status: RESOLVED DUPLICATE of bug 1148750

(Core :: JavaScript: Standard Library, defect)

Description

[André Bargull [:anba]]

JSObject::defineElement() allows to overwrite non-configurable properties, so it probably shouldn't be used directly in array_of().


Test case 1:
---
function C() {
  Object.defineProperty(this, 0, {value: "v", configurable: false});
}
Array.of.call(C, 1, 2, 3)
---

Expected: Throws TypeError
Actual: No error


Test case 2:
---
var obj;
function C() {
  obj = this;
  Object.defineProperty(this, 0, {value: "v", configurable: false});
  print(JSON.stringify(Object.getOwnPropertyDescriptor(this, 0)));
}
try { Array.of.call(C, 1); } catch (e) {}
Object.getOwnPropertyDescriptor(obj, "0");
---

Expected: Non-configurable property is not changed
Actual: Non-configurable property is changed (writable, enumerable and value are changed)

Comment 1

[Jason Orendorff [:jorendorff]]

I believe a patch I'm developing for bug 1148750 fixes this.

Comment 2

[Jason Orendorff [:jorendorff]]

André, thanks once again. I'll check in these test cases in bug 1148750, assuming you don't mind, as always.

Comment 3

[Jason Orendorff [:jorendorff]]

Done.