Ticket #14601: promote_alias.diff

django/db/models/sql/query.py

@@ -641 +641 @@
         False, the join is only promoted if it is nullable, otherwise it is
         always promoted.
 
-        Returns True if the join was promoted.
+        Returns True if the join was promoted or had been previously.
         """
-        if ((unconditional or self.alias_map[alias][NULLABLE]) and
-                self.alias_map[alias][JOIN_TYPE] != self.LOUTER):
-            data = list(self.alias_map[alias])
-            data[JOIN_TYPE] = self.LOUTER
-            self.alias_map[alias] = tuple(data)
+        if unconditional or self.alias_map[alias][NULLABLE]:
+            if self.alias_map[alias][JOIN_TYPE] != self.LOUTER:
+                data = list(self.alias_map[alias])
+                data[JOIN_TYPE] = self.LOUTER
+                self.alias_map[alias] = tuple(data)
             return True
         return False
 

tests/modeltests/promote_alias/__init__.py

@@ +1 @@
+

tests/modeltests/promote_alias/models.py

@@ +1 @@
+"""
+Testing query promote_alias bug.
+"""
+
+from django.db import models
+
+class User(models.Model):
+    first_name = models.CharField(max_length=100)
+    last_name = models.CharField(max_length=100)
+    
+class Person(models.Model):
+    user = models.ForeignKey(User)
+
+class Item(models.Model):
+    person = models.ForeignKey(Person, null=True)
+    amount = models.IntegerField()
+
+
+__test__ = {'API_TESTS':"""
+>>> from django.db.models import Q
+
+>>> Item.objects.create(person=None, amount=123)
+<Item: Item object>
+
+>>> Item.objects.values('amount', 'person__user__first_name', 'person__user__last_name')
+[{'amount': 123, 'person__user__last_name': None, 'person__user__first_name': None}]
+
+>>> Item.objects.filter(Q(person__isnull=True) | Q(person__isnull=False))
+[<Item: Item object>]
+
+>>> Item.objects.filter(Q(person__isnull=True) | Q(person__isnull=False)).values('amount', 'person__user__first_name', 'person__user__last_name')
+[{'amount': 123, 'person__user__last_name': None, 'person__user__first_name': None}]
+
+"""}