diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/splice-call-plain-object-590780.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/splice-call-plain-object-590780.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,8 @@
+var o = { 0: 1, 1: 2, 2: 3, length: 3 };
+Array.prototype.splice.call(o, 0, 1);
+
+assertEq(o[0], 2);
+assertEq(o[1], 3);
+assertEq(Object.getOwnPropertyDescriptor(o, 2), undefined);
+assertEq("2" in o, false);
+assertEq(o.length, 2);