diff -r 000000000000 -r 6474c204b198 js/xpconnect/tests/unit/test_bug_442086.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/xpconnect/tests/unit/test_bug_442086.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,36 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// Bug 442086 - XPConnect creates doubles without checking for
+//              the INT_FITS_IN_JSVAL case
+
+var types = [
+    'PRUint8',
+    'PRUint16',
+    'PRUint32',
+    'PRUint64',
+    'PRInt16',
+    'PRInt32',
+    'PRInt64',
+    'float',
+    'double'
+];
+
+function run_test()
+{
+  var i;
+  for (i = 0; i < types.length; i++) {
+    var name = types[i];
+    var cls = Components.classes["@mozilla.org/supports-" + name + ";1"];
+    var ifname = ("nsISupports" + name.charAt(0).toUpperCase() +
+                  name.substring(1));
+    var f = cls.createInstance(Components.interfaces[ifname]);
+
+    f.data = 0;
+    switch (f.data) {
+      case 0: /*ok*/ break;
+      default: do_throw("FAILED - bug 442086 (type=" + name + ")");
+    }
+  }
+}