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 function f(arr)

 {

   assertEq(arr.shift(), 0);

 }

 function test(out)

 {

   // Create an array of arrays, to be iterated over for [].shift-calling.  We

   // can't just loop on shift on a single array with non-writable length because

   // shift throws when called on an array with non-writable length.

   var arrs = out.arrs = [];

   for (var i = 0; i < 100; i++)

     arrs.push([0, 1, 2, 3]);

   // Use a much-greater capacity than the eventual non-writable length.

   var a = [0, 1, 2, 3, 4, 5, 6, 7];

   Object.defineProperty(a, "length", { writable: false, value: 4 });

   arrs.push(a);

   for (var i = 0, sz = arrs.length; i < sz; i++)

   {

     var arr = arrs[i];

     f(arr);

   }

 }

 var obj = {};

 var a, arrs;

 try

 {

   test(obj);

   throw new Error("didn't throw!");

 }

 catch (e)

 {

   assertEq(e instanceof TypeError, true, "expected TypeError, got " + e);

   arrs = obj.arrs;

   assertEq(arrs.length, 101);

   for (var i = 0; i < 100; i++)

   {

     assertEq(arrs[i].length, 3, "unexpected length for arrs[" + i + "]");

     assertEq(arrs[i][0], 1, "bad element for arrs[" + i + "][0]");

     assertEq(arrs[i][1], 2, "bad element for arrs[" + i + "][1]");

     assertEq(arrs[i][2], 3, "bad element for arrs[" + i + "][2]");

     assertEq(3 in arrs[i], false, "shouldn't be a third element");

     assertEq(arrs[i][3], undefined);

   }

   a = arrs[100];

   assertEq(a[0], 1, "bad element for a[" + i + "]");

   assertEq(a[1], 2, "bad element for a[" + i + "]");

   assertEq(a[2], 3, "bad element for a[" + i + "]");

   assertEq(a.hasOwnProperty(3), false, "should have been deleted before throw");

   assertEq(a[3], undefined);

   assertEq(a.length, 4, "length shouldn't have been changed");

 }