1 files changed, 61 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/arrays/unshift-nonwritable-length.js b/js/src/jit-test/tests/arrays/unshift-nonwritable-length.js
new file mode 100644
index 0000000000..db95c5f2ef
--- /dev/null
+++ b/js/src/jit-test/tests/arrays/unshift-nonwritable-length.js
@@ -0,0 +1,61 @@
+load(libdir + "asserts.js");
+
+function f(arr)
+{
+  assertEq(arr.unshift(3, 5, 7, 9), 8); // if it doesn't throw :-)
+}
+
+var N = 100;
+
+function test(out)
+{
+  // Create an array of arrays, to be iterated over for [].unshift-calling.  We
+  // can't just loop on unshift on a single array with non-writable length
+  // because unshift throws when called on an array with non-writable length.
+  var arrs = out.arrs = [];
+  for (var i = 0; i < N; i++)
+    arrs.push([0, 1, 2, 3]);
+
+  // Use a much-greater capacity than the eventual non-writable length, just for
+  // variability.
+  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++)
+    f(arrs[i]);
+}
+
+var obj = {};
+assertThrowsInstanceOf(function() { test(obj); }, TypeError);
+
+var arrs = obj.arrs;
+assertEq(arrs.length, N + 1);
+for (var i = 0; i < N; i++)
+{
+  assertEq(arrs[i].length, 8, "unexpected length for arrs[" + i + "]");
+  assertEq(arrs[i][0], 3, "bad element for arrs[" + i + "][0]");
+  assertEq(arrs[i][1], 5, "bad element for arrs[" + i + "][1]");
+  assertEq(arrs[i][2], 7, "bad element for arrs[" + i + "][2]");
+  assertEq(arrs[i][3], 9, "bad element for arrs[" + i + "][3]");
+  assertEq(arrs[i][4], 0, "bad element for arrs[" + i + "][4]");
+  assertEq(arrs[i][5], 1, "bad element for arrs[" + i + "][5]");
+  assertEq(arrs[i][6], 2, "bad element for arrs[" + i + "][6]");
+  assertEq(arrs[i][7], 3, "bad element for arrs[" + i + "][7]");
+}
+
+var a = arrs[N];
+assertEq(a[0], 0, "bad element for a[0]");
+assertEq(a[1], 1, "bad element for a[1]");
+assertEq(a[2], 2, "bad element for a[2]");
+assertEq(a[3], 3, "bad element for a[3]");
+assertEq(a.hasOwnProperty(4), false, "shouldn't have added any elements");
+assertEq(a[4], undefined);
+assertEq(a.hasOwnProperty(5), false, "shouldn't have added any elements");
+assertEq(a[5], undefined);
+assertEq(a.hasOwnProperty(6), false, "shouldn't have added any elements");
+assertEq(a[6], undefined);
+assertEq(a.hasOwnProperty(7), false, "shouldn't have added any elements");
+assertEq(a[7], undefined);
+assertEq(a.length, 4, "length shouldn't have been changed");