Support negated filters on one-to-one Relationships

Author: camuthig

relativity/fields.py

@@ -402,15 +402,17 @@ def contribute_to_class(self, cls, name, **kwargs):
         setattr(cls, self.name, self.accessor_class(self))
 
     def get_path_info(self, filtered_relation=None):
+        is_m2m = self.multiple or self.reverse_multiple
+
         if django.VERSION < (2, 0):
             to_opts = self.rel.to._meta
             from_opts = self.model._meta
-            return [PathInfo(from_opts, to_opts, (to_opts.pk,), self, True, False)]
+            return [PathInfo(from_opts, to_opts, (to_opts.pk,), self, is_m2m, False)]
         to_opts = self.remote_field.model._meta
         from_opts = self.model._meta
         return [
             PathInfo(
-                from_opts, to_opts, (to_opts.pk,), self, True, False, filtered_relation
+                from_opts, to_opts, (to_opts.pk,), self, is_m2m, False, filtered_relation
             )
         ]
 

tests/tests.py

@@ -364,6 +364,24 @@ def test_single_reverse(self):
         self.assertIsNone(node_3.next)
         self.assertIsNone(node_1.prev)
 
+    def test_single_exclude_forward(self):
+        node_1 = LinkedNode.objects.create(
+            name="first node",
+            prev_id=None,
+        )
+        node_2 = LinkedNode.objects.create(
+            name="next node",
+            prev_id=node_1.id,
+        )
+        node_3 = LinkedNode.objects.create(
+            name="last node",
+            prev_id=node_2.id,
+        )
+
+        qs = LinkedNode.objects.exclude(next__name__contains="last")
+
+        self.assertEqual(qs.count(), 2)
+
     def test_not_nullable(self):
         item = CartItem.objects.create(
             pk=4,