diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug679977.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug679977.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,26 @@
+var Test = function (foo) {
+    var a = [];
+
+    this.fillArray = function() {
+        a = [];
+        for (var i = 0; i < 10; i++)
+            a.push(0);
+        assertEq(a.length, 10);
+    }
+
+    foo.go(this);
+};
+
+// Import assertEq now to prevent global object shape from changing.
+assertEq(true, true);
+
+(new Test({ go: function(p) {
+    p.fill = function() {
+        p.fillArray();
+    }
+}})).fill();
+
+new Test({ go: function(p) {
+    for (var k = 0; k < 10; k++)
+        p.fillArray();
+}});