diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug630865-6.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug630865-6.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,11 @@
+var a = [];
+var x, i;
+for (i = 0; i < 18; i++) {
+    a[i] = function (b) { this.b = b; };
+    if (i != 17)
+        x = a[i].prototype;
+}
+for (i = 0; i < 18; i++)
+    x = new a[i];
+assertEq(toString.call(x), "[object Object]");
+assertEq(Object.getPrototypeOf(x), a[17].prototype);