1 files changed, 10 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/basic/bug646968-4.js b/js/src/jit-test/tests/basic/bug646968-4.js
new file mode 100644
index 0000000000..fdcafbb2b1
--- /dev/null
+++ b/js/src/jit-test/tests/basic/bug646968-4.js
@@ -0,0 +1,10 @@
+load(libdir + "asserts.js");
+
+// Scoping: `x` in the head of a `for (let x...)` loop refers to the loop variable.
+
+assertThrowsInstanceOf(function () {
+var s = "", x = {a: 1, b: 2, c: 3};
+for (let x in eval('x'))
+    s += x;
+assertEq(s, "");
+}, ReferenceError);