diff -r 000000000000 -r 6474c204b198 modules/libjar/test/unit/test_bug336691.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/modules/libjar/test/unit/test_bug336691.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,12 @@
+// Regression test for bug 336691 - nsZipArchive::Test shouldn't try to ExtractFile on directories.
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+
+function run_test() {
+  var file = do_get_file("data/test_bug336691.zip");
+  var zipReader = Cc["@mozilla.org/libjar/zip-reader;1"].
+                  createInstance(Ci.nsIZipReader);
+  zipReader.open(file);
+  zipReader.test(null); // We shouldn't crash here.
+  zipReader.close();
+}