Fixed #25915 -- Allowed language not in Django's default LANGUAGES

This fixes a regression introduced by a5f6cbce07.
Thanks Gavin Wahl for the report and Tim Graham for the review.

tests/i18n/commands/locale/xxx/LC_MESSAGES/django.po

@@ -0,0 +1,21 @@
+# SOME DESCRIPTIVE TITLE.
+# Copyright (C) YEAR THE PACKAGE'S COPYRIGHT HOLDER
+# This file is distributed under the same license as the PACKAGE package.
+# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
+#
+msgid ""
+msgstr ""
+"Project-Id-Version: PACKAGE VERSION\n"
+"Report-Msgid-Bugs-To: \n"
+"POT-Creation-Date: 2011-12-04 04:59-0600\n"
+"PO-Revision-Date: 2011-12-10 19:12-0300\n"
+"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
+"Language-Team: LANGUAGE <LL@li.org>\n"
+"Language: xxx\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Plural-Forms: nplurals=2; plural=(n != 1)\n"
+
+msgid "year"
+msgstr "reay"

tests/i18n/tests.py

@@ -1849,3 +1849,22 @@ class TranslationFilesMissing(SimpleTestCase):
         self.patchGettextFind()
         trans_real._translations = {}
         self.assertRaises(IOError, activate, 'en')
+
+
+class NonDjangoLanguageTests(SimpleTestCase):
+    """
+    A language non present in default Django languages can still be
+    installed/used by a Django project.
+    """
+    @override_settings(
+        USE_I18N=True,
+        LANGUAGES=[
+            ('en-us', 'English'),
+            ('xxx', 'Somelanguage'),
+        ],
+        LANGUAGE_CODE='xxx',
+        LOCALE_PATHS=[os.path.join(here, 'commands', 'locale')],
+    )
+    def test_non_django_language(self):
+        self.assertEqual(get_language(), 'xxx')
+        self.assertEqual(ugettext("year"), "reay")