diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/gc/bug-992866.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/gc/bug-992866.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,15 @@
+if (!getBuildConfiguration().parallelJS)
+  quit(0);
+
+test([0], "map", function (... Object)  {
+  var x = [];
+  for (var i = 0; i < 10; i++) {
+      x[i] = {};
+  }
+});
+
+function test(arr, op, func) {
+  for (var i = 0; i < 1000; i++) {
+    arr[op + "Par"].apply(arr, [func, undefined]);
+  }
+}