// Force recognition of a known-constant. var push = Array.prototype.push; function f(arr) { // Push an actual constant to trigger JIT-inlining of the effect of the push. push.call(arr, 99); } function basic(out) { // Create an array of arrays, to be iterated over for [].push-calling. We // can't just loop on push on a single array with non-writable length because // push throws when called on an array with non-writable length. var arrs = out.arrs = []; for (var i = 0; i < 100; i++) arrs.push([]); // Use a much-greater capacity than the eventual non-writable length. var a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]; Object.defineProperty(a, "length", { writable: false, value: 6 }); arrs.push(a); for (var i = 0, sz = arrs.length; i < sz; i++) { var arr = arrs[i]; f(arr); } } var obj = {}; var arrs, a; try { basic(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, 1, "unexpected length for arrs[" + i + "]"); assertEq(arrs[i][0], 99, "bad element for arrs[" + i + "]"); } a = arrs[100]; assertEq(a.hasOwnProperty(6), false); assertEq(a[6], undefined); assertEq(a.length, 6); }