Mutate the parent closure named arguments via arguments from outside

change.js

// NOTE does not work in strict mode
function parent(a, b) {
  console.log('in parent, a', a, 'b', b);
  var parentArguments = arguments;

  function child() {
    console.log('in child, a', a, 'b', b);
    console.log('is parentArguments === c.args?', parentArguments === c.args);
    console.log('parentArguments', parentArguments);
    return a + b;
  }

  child.args = parentArguments;
  return child;
}

var c = parent(0, 1);
// can we change a and b inside the "c"?

c.args['0'] = 'foo';
c.args['1'] = 'bar';

console.log(c());
// "foobar"

One can even pass list of undefined to the parent function - as long as the arguments number is >= expected it is working, one can mutate the named arguments from the outside

var c = parent.apply(null, new Array(parent.length));

Smells like a bug to me.