- fix distinct with *fields

modeltranslation/manager.py

@@ -249,6 +249,7 @@ def _rewrite_applied_operations(self):
         if not NEW_RELATED_API:
             self._rewrite_where(self.query.having)
         self._rewrite_order()
+        self._rewrite_distinct()
         self._rewrite_select_related()
 
     # This method was not present in django-linguo
@@ -304,6 +305,10 @@ def _rewrite_order(self):
         self.query.order_by = [rewrite_order_lookup_key(self.model, field_name)
                                for field_name in self.query.order_by]
 
+    def _rewrite_distinct(self):
+        self.query.distinct_fields = [rewrite_lookup_key(self.model, field_name)
+                                      for field_name in self.query.distinct_fields]
+
     def _rewrite_select_related(self):
         if isinstance(self.query.select_related, dict):
             new = {}

modeltranslation/tests/tests.py

@@ -2540,6 +2540,25 @@ def test_order_by(self):
         self.assertEqual(titles_asc, ('a', 'b', 'c'))
         self.assertEqual(titles_desc, ('c', 'b', 'a'))
 
+    def test_distinct(self):
+        """
+        Check that field names are rewritten in distinct fields.
+        This test works only on postgres.
+        """
+        db_engine = django_settings.DATABASES['default']['ENGINE']
+        if db_engine != 'django.db.backends.postgresql_psycopg2':
+            return
+
+        manager = models.ManagerTestModel.objects
+        manager.create(title='a')
+        manager.create(title='b')
+        manager.create(title='b')
+        manager.create(title='c')
+        manager.create(title='c')
+        manager.create(title='c')
+        titles = tuple(m.title for m in manager.order_by('title').distinct('title'))
+        self.assertEqual(titles, ('a', 'b', 'c'))
+
     def test_order_by_meta(self):
         """Check that meta ordering is rewritten."""
         manager = models.ManagerTestModel.objects