Allow to disable language code mappings

In some rare cases this causes troubles as few projects translate to
both fr and fr-FR.

Issue #437

docs/admin/config.rst

@@ -347,6 +347,18 @@ Enables self advertisement of Weblate in case there are no configured ads.
 
 .. seealso:: :ref:`advertisement`
 
+.. setting:: SIMPLIFY_LANGUAGES
+
+SIMPLIFY_LANGUAGES
+------------------
+
+Use simple language codes for default language/country combinations. For
+example ``fr_FR`` translation will use ``fr`` language code. This is usually
+desired behavior as it simplifies listing of the languages for these default
+combinations.
+
+Disable this if you are having different translations for both variants.
+
 .. setting:: SITE_TITLE
 
 SITE_TITLE

weblate/appsettings.py

@@ -161,3 +161,6 @@ SOURCE_LANGUAGE = get('SOURCE_LANGUAGE', 'en')
 
 # Self advertisement
 SELF_ADVERTISEMENT = get('SELF_ADVERTISEMENT', False)
+
+# Use simple language codes for default language/country combinations
+SIMPLIFY_LANGUAGES = GET('SIMPLIFY_LANGUAGES', True)

weblate/lang/models.py

@@ -28,6 +28,7 @@ from weblate.trans.mixins import PercentMixin
 from south.signals import post_migrate
 from django.db.models.signals import post_syncdb
 from django.dispatch import receiver
+from weblate.appsettings import SIMPLIFY_LANGUAGES
 import weblate
 
 # Plural types definition
@@ -166,7 +167,7 @@ class LanguageManager(models.Manager):
             return ret
 
         # Try canonical variant
-        if newcode in data.DEFAULT_LANGS:
+        if SIMPLIFY_LANGUAGES and newcode in data.DEFAULT_LANGS:
             ret = self.try_get(lang.lower())
             if ret is not None:
                 return ret