Consolidated duplicate to_locale() implementations.

Follow up to ac59ec8f1a.

django/utils/translation/__init__.py

@@ -194,7 +194,19 @@ def check_for_language(lang_code):
 
 
 def to_locale(language):
-    return _trans.to_locale(language)
+    """Turn a language name (en-us) into a locale name (en_US)."""
+    language = language.lower()
+    parts = language.split('-')
+    try:
+        country = parts[1]
+    except IndexError:
+        return language
+    # A language with > 2 characters after the dash only has its first
+    # character after the dash capitalized; e.g. sr-latn becomes sr_Latn.
+    # A language with 2 characters after the dash has both characters
+    # capitalized; e.g. en-us becomes en_US.
+    parts[1] = country.title() if len(country) > 2 else country.upper()
+    return parts[0] + '_' + '-'.join(parts[1:])
 
 
 def get_language_from_request(request, check_path=False):

django/utils/translation/trans_null.py

@@ -4,8 +4,6 @@
 
 from django.conf import settings
 
-from .trans_real import to_locale as trans_real_to_locale
-
 
 def gettext(message):
     return message
@@ -54,9 +52,6 @@ def check_for_language(x):
     return True
 
 
-to_locale = trans_real_to_locale
-
-
 def get_language_from_request(request, check_path=False):
     return settings.LANGUAGE_CODE
 

django/utils/translation/trans_real.py

@@ -15,7 +15,8 @@ from django.core.exceptions import AppRegistryNotReady
 from django.core.signals import setting_changed
 from django.dispatch import receiver
 from django.utils.safestring import SafeData, mark_safe
-from django.utils.translation import LANGUAGE_SESSION_KEY
+
+from . import LANGUAGE_SESSION_KEY, to_locale
 
 # Translations are cached in a dictionary for every language.
 # The active translations are stored by threadid to make them thread local.
@@ -56,23 +57,6 @@ def reset_cache(**kwargs):
         get_supported_language_variant.cache_clear()
 
 
-def to_locale(language):
-    """Turn a language name (en-us) into a locale name (en_US)."""
-    language = language.lower()
-    parts = language.split('-')
-    try:
-        country = parts[1]
-    except IndexError:
-        return language
-    else:
-        # A language with > 2 characters after the dash only has its first
-        # character after the dash capitalized; e.g. sr-latn becomes sr_Latn.
-        # A language with 2 characters after the dash has both characters
-        # capitalized; e.g. en-us becomes en_US.
-        parts[1] = country.title() if len(country) > 2 else country.upper()
-    return parts[0] + '_' + '-'.join(parts[1:])
-
-
 def to_language(locale):
     """Turn a locale name (en_US) into a language name (en-us)."""
     p = locale.find('_')

tests/i18n/tests.py

@@ -286,7 +286,6 @@ class TranslationTests(SimpleTestCase):
         for lang, locale in tests:
             with self.subTest(lang=lang):
                 self.assertEqual(to_locale(lang), locale)
-                self.assertEqual(trans_null.to_locale(lang), locale)
 
     def test_to_language(self):
         self.assertEqual(trans_real.to_language('en_US'), 'en-us')