diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/parallel/bug909743.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/parallel/bug909743.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,21 @@
+if (getBuildConfiguration().parallelJS) {
+  function assertParallelExecSucceeds(opFunction) {
+    for (var i = 0; i < 100; ++i) {
+      opFunction({mode:"compile"});
+    }
+  }
+  function assertArraySeqParResultsEq(arr, op, func) {
+    assertParallelExecSucceeds(
+      function (m) { 
+        return arr[op + "Par"].apply(arr, [func, m]); 
+      }
+    );
+  }
+  function range(n, m) {
+    var result = [];
+    for (var i = n; i < m; i++)
+      result.push(i);
+    return result;
+  }
+  assertArraySeqParResultsEq(range(0, 512), "map", function(e) { return e+'x'; });
+}