diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/testAssigningWatchedDeletedProperty.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/testAssigningWatchedDeletedProperty.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,7 @@
+var o = {};
+o.watch("p", function() { });
+
+for (var i = 0; i < 10; i++) {
+    o.p = 123;
+    delete o.p;
+}