544166 - ES5 non-strict mode: arguments[i] should alias parameters even after return

Status: RESOLVED DUPLICATE of bug 478174

(Core :: JavaScript Engine, defect)

Description

[David Mandelin [:dmandelin]]

At least I think so. That part of the spec is kind of hard to read, but it seems to be saying this. JSC and V8 do alias them even after return. Here is a test case that shows it:

    var args;
    var g;
    var p;

    function f(a) {
      args = arguments;
      g = function() { ++a; };
      p = function() { print(a); };
    }

    f(0);
    p();
    g();
    print(args[0]);
    ++args[0];
    p();

Comment 1

[Brendan Eich [:brendan]]

Yes, Richard Cornford raised this on es-discuss a while ago:

https://mail.mozilla.org/pipermail/es-discuss/2008-July/006618.html

I copped to it here:

https://mail.mozilla.org/pipermail/es-discuss/2008-July/006625.html

Guess it is time to fix.

/be

Comment 2

[Jason Orendorff [:jorendorff]]

Bug 478174 has a shorter test case.