Fix renaming annotations in Django 2.0

Author: Photonios

psqlextra/query.py

@@ -1,3 +1,5 @@
+import django
+
 from enum import Enum
 from typing import List, Tuple, Optional, Dict, Any
 from collections import OrderedDict
@@ -43,8 +45,10 @@ def rename_annotations(self, annotations) -> None:
 
             self._annotations = OrderedDict(
                 [(new_name, v) if k == old_name else (k, v) for k, v in self._annotations.items()])
-            self.set_annotation_mask(
-                (new_name if v == old_name else v for v in (self.annotation_select_mask or [])))
+
+            if django.VERSION < (2, 0):
+                self.set_annotation_mask(
+                    (new_name if v == old_name else v for v in self.annotation_select_mask))
 
     def add_join_conditions(self, conditions: Dict[str, Any]) -> None:
         """Adds an extra condition to an existing JOIN.

tests/test_query.py

@@ -3,6 +3,8 @@
 from psqlextra.fields import HStoreField
 from psqlextra.expressions import HStoreRef
 
+from django.db.models import F
+
 from .fake_model import get_fake_model
 
 
@@ -33,6 +35,20 @@ def test_annotate_hstore_key_ref():
     assert queryset['english_title'] == 'english'
 
 
+def test_annotate_rename():
+    """Tests whether field names can be overwritten
+    with a annotated field."""
+
+    model = get_fake_model({
+        'title': models.CharField(max_length=12),
+    })
+
+    model.objects.create(title='swen')
+
+    obj = model.objects.annotate(title=F('title')).first()
+    assert obj.title == 'swen'
+
+
 def test_hstore_f_ref():
     """Tests whether F(..) expressions can be used in
     hstore values when performing update queries."""