diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/baseline/bug848743-1.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/baseline/bug848743-1.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,42 @@
+function A() {};
+A.prototype = [];
+
+function B() {};
+B.prototype = new A();
+
+function C() {};
+C.prototype = new B();
+
+function D() {};
+D.prototype = new C();
+
+function E() {};
+E.prototype = new D();
+
+function f() {
+    var o = new B();
+    for (var i=0; i<10; i++)
+	o[i] = i;
+
+    var expected = '{"0":0,"1":1,"2":2,"3":3,"4":4,"5":5,"6":6,"7":7,"8":8,"9":9}';
+    assertEq(JSON.stringify(o), expected);
+
+    var o = new A();
+    for (var i=0; i<10; i++)
+	o[i] = i;
+
+    assertEq(JSON.stringify(o), expected);
+
+    var o = new D();
+    for (var i=0; i<10; i++)
+	o[i] = i;
+
+    assertEq(JSON.stringify(o), expected);
+
+    var o = new E();
+    for (var i=0; i<10; i++)
+	o[i] = i;
+
+    assertEq(JSON.stringify(o), expected);
+}
+f();