diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_8_5/extensions/regress-627984-2.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_8_5/extensions/regress-627984-2.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,15 @@
+// Any copyright is dedicated to the Public Domain.
+// http://creativecommons.org/licenses/publicdomain/
+
+// See bug 627984, comment 17, item 2.
+var obj = {};
+var x;
+obj.watch("m", function (id, oldval, newval) {
+        x = this.m;
+        return newval;
+    });
+delete obj.m;
+obj.m = function () { return this.method; };
+obj.m = 2;
+
+reportCompare(0, 0, 'ok');