diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_7/extensions/regress-590813.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_7/extensions/regress-590813.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,23 @@
+
+var actual = '';
+var expected = 'A0B1B2C0C1C2';
+
+var x = Iterator([1,2,3], true);
+
+for (var a in x) {
+  actual += 'A' + a;
+  for (var b in x) {
+    actual += 'B' + b;
+  }
+}
+
+var y = Iterator([1,2,3], true);
+
+for (var c in y) {
+  actual += 'C' + c;
+}
+for (var d in y) {
+  actual += 'D' + d;
+}
+
+reportCompare(expected, actual, "Handle nested Iterator iteration right");