1 files changed, 9 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/basic/bug631305.js b/js/src/jit-test/tests/basic/bug631305.js
new file mode 100644
index 000000000..b0cbbbb24
--- /dev/null
+++ b/js/src/jit-test/tests/basic/bug631305.js
@@ -0,0 +1,9 @@
+var n = 0;
+var a = [];
+for (var i = 0; i < 20; i++)
+    a[i] = {};
+a[18].watch("p", function () { n++; });
+delete a[18].p;
+for (var i = 0; i < 20; i++)
+    a[i].p = 0;
+assertEq(n, 1);