diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug630377.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug630377.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,7 @@
+var a = [];
+for (var i = 0; i < 9; i++)
+    a[i] = 0;
+var b = [x === "0" && true for (x in a)];
+assertEq(b[0], true);
+for (var i = 1; i < 9; i++)
+    assertEq(b[i], false);