diff -r 000000000000 -r 6474c204b198 intl/uconv/tests/plattest.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/intl/uconv/tests/plattest.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,46 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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/. */
+#include "nsIPlatformCharset.h"
+#include "nsILocaleService.h"
+#include "nsCOMPtr.h"
+#include "nsReadableUtils.h"
+#include "nsIComponentManager.h"
+#include <stdio.h>
+
+int
+main(int argc, const char** argv)
+{
+
+    nsCOMPtr<nsIPlatformCharset> platform_charset = 
+        do_CreateInstance(NS_PLATFORMCHARSET_CONTRACTID);
+    if (!platform_charset) return -1;
+
+    nsCOMPtr<nsILocaleService>      locale_service = 
+        do_CreateInstance(NS_LOCALESERVICE_CONTRACTID);
+    if (!locale_service) return -1;
+
+    nsCOMPtr<nsILocale>             locale;
+    nsAutoCString                   charset;
+    nsAutoString                    category;
+
+    nsresult rv = locale_service->GetSystemLocale(getter_AddRefs(locale));
+    if (NS_FAILED(rv)) return -1;
+
+    rv = locale->GetCategory(NS_LITERAL_STRING("NSILOCALE_MESSAGES"), category);
+    if (NS_FAILED(rv)) return -1;
+
+    rv = platform_charset->GetDefaultCharsetForLocale(category, charset);
+    if (NS_FAILED(rv)) return -1;
+
+    printf("DefaultCharset for %s is %s\n", NS_LossyConvertUTF16toASCII(category).get(), charset.get());
+
+    category.AssignLiteral("en-US");
+    rv = platform_charset->GetDefaultCharsetForLocale(category, charset);
+    if (NS_FAILED(rv)) return -1;
+
+    printf("DefaultCharset for %s is %s\n", NS_LossyConvertUTF16toASCII(category).get(), charset.get());
+
+    return 0;
+}