diff -r 000000000000 -r 6474c204b198 xpcom/tests/unit/test_home.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/tests/unit/test_home.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,24 @@
+const Ci = Components.interfaces;
+const Cc = Components.classes;
+
+const CWD = do_get_cwd();
+function checkOS(os) {
+  const nsILocalFile_ = "nsILocalFile" + os;
+  return nsILocalFile_ in Components.interfaces &&
+         CWD instanceof Components.interfaces[nsILocalFile_];
+}
+
+const isWin = checkOS("Win");
+
+function run_test() {
+  var envVar = isWin ? "USERPROFILE" : "HOME";
+
+  var dirSvc = Cc["@mozilla.org/file/directory_service;1"].getService(Ci.nsIProperties);
+  var homeDir = dirSvc.get("Home", Ci.nsIFile);
+
+  var env = Cc["@mozilla.org/process/environment;1"].getService(Ci.nsIEnvironment);
+  var expected = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsILocalFile);
+  expected.initWithPath(env.get(envVar));
+
+  do_check_eq(homeDir.path, expected.path);
+}