make the glibc alias table take precedence over the X11 one (#422)

bpo-20087

Lib/test/test_locale.py

@@ -449,7 +449,7 @@ class NormalizeTest(unittest.TestCase):
         self.check('ko_kr.euckr', 'ko_KR.eucKR')
         self.check('zh_cn.euc', 'zh_CN.eucCN')
         self.check('zh_tw.euc', 'zh_TW.eucTW')
-        self.check('zh_tw.euctw', 'zh_TW.eucTW')
+        self.check('zh_tw.euctw', 'zh_TW.EUC_TW')
 
     def test_japanese(self):
         self.check('ja', 'ja_JP.eucJP')
@@ -475,6 +475,9 @@ class NormalizeTest(unittest.TestCase):
         self.check('japanese.sjis', 'ja_JP.SJIS')
         self.check('jp_jp', 'ja_JP.eucJP')
 
+    def test_en_IN(self):
+        self.check('en_IN', 'en_IN.UTF-8')
+
 
 class TestMiscellaneous(unittest.TestCase):
     def test_getpreferredencoding(self):

Misc/NEWS

@@ -19,6 +19,8 @@ Core and Builtins
 - bpo-29695: bool(), float(), list() and tuple() no longer take keyword arguments.
   The first argument of int() can now be passes only as positional argument.
 
+- bpo-20087: Prefer glibc's list of locale aliases to the X11 ones.
+
 - bpo-28893: Set correct __cause__ for errors about invalid awaitables
   returned from __aiter__ and __anext__.
 

Tools/i18n/makelocalealias.py

@@ -135,8 +135,8 @@ if __name__ == '__main__':
     args = parser.parse_args()
 
     data = locale.locale_alias.copy()
-    data.update(parse_glibc_supported(args.glibc_supported))
     data.update(parse(args.locale_alias))
+    data.update(parse_glibc_supported(args.glibc_supported))
     while True:
         # Repeat optimization while the size is decreased.
         n = len(data)