1 files changed, 7 insertions, 0 deletions
diff --git a/js/xpconnect/tests/unit/test_bug849730.js b/js/xpconnect/tests/unit/test_bug849730.js
new file mode 100644
index 000000000..8622b5bca
--- /dev/null
+++ b/js/xpconnect/tests/unit/test_bug849730.js
@@ -0,0 +1,7 @@
+const Cu = Components.utils;
+
+function run_test() {
+  var sb = new Cu.Sandbox('http://www.example.com');
+  sb.arr = [3, 4];
+  do_check_true(Cu.evalInSandbox('!Array.isArray(arr);', sb));
+}