diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/jaeger/bug679666.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/jaeger/bug679666.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,22 @@
+var arr = new Int32Array(20);
+
+function f(a1, a2) {
+    for (var i=0; i<10; i++) {
+        g1 = a2;
+        arr[a1] = a2;
+        assertEq(g1, a2);
+
+        if ([1].length === 10) {
+            a1 = {};
+        }
+    }
+}
+
+f(1, eval("{}"));
+
+for (var i=0; i<5; i++) {
+    f(2, 3);
+    f(5, -6.1);
+}
+assertEq(arr[2], 3);
+assertEq(arr[5], -6);