diff -r 000000000000 -r 6474c204b198 services/sync/tps/extensions/mozmill/resource/stdlib/os.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/services/sync/tps/extensions/mozmill/resource/stdlib/os.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,57 @@
+/* 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/. */
+
+var EXPORTED_SYMBOLS = ['listDirectory', 'getFileForPath', 'abspath', 'getPlatform'];
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cu = Components.utils;
+
+Cu.import("resource://gre/modules/Services.jsm");
+
+function listDirectory(file) {
+  // file is the given directory (nsIFile)
+  var entries = file.directoryEntries;
+  var array = [];
+
+  while (entries.hasMoreElements()) {
+    var entry = entries.getNext();
+    entry.QueryInterface(Ci.nsIFile);
+    array.push(entry);
+  }
+
+  return array;
+}
+
+function getFileForPath(path) {
+  var file = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsILocalFile);
+  file.initWithPath(path);
+  return file;
+}
+
+function abspath(rel, file) {
+  var relSplit = rel.split('/');
+
+  if (relSplit[0] == '..' && !file.isDirectory()) {
+    file = file.parent;
+  }
+
+  for each(var p in relSplit) {
+    if (p == '..') {
+      file = file.parent;
+    } else if (p == '.') {
+      if (!file.isDirectory()) {
+        file = file.parent;
+      }
+    } else {
+      file.append(p);
+    }
+  }
+
+  return file.path;
+}
+
+function getPlatform() {
+  return Services.appinfo.OS.toLowerCase();
+}