Refs #36385 -- Removed QuerySet._defer_next_filter.

Added a `defer` argument to `QuerySet._filter_q()` instead. As we're immediately performing a `.filter()` call, make use of the underlying internal `._filter_q()` method and pass a flag directly.
django · ngnpope · Apr 30, 2025 · Apr 30, 2025 · Apr 30, 2025 · Apr 30, 2025
commit 46a4c47eddb6ff58638e7cd9920bd892e0aa1b2f
diff --git a/django/db/models/fields/related_descriptors.py b/django/db/models/fields/related_descriptors.py
@@ -687,8 +687,7 @@ def _apply_rel_filters(self, queryset):
             queryset._add_hints(instance=self.instance)
             if self._db:
                 queryset = queryset.using(self._db)
-            queryset._defer_next_filter = True
-            queryset = queryset.filter(**self.core_filters)
+            queryset = queryset._filter_q(Q(**self.core_filters), defer=True)
             for field in self.field.foreign_related_fields:
                 val = getattr(self.instance, field.attname)
                 if val is None or (val == "" and empty_strings_as_null):
@@ -1088,8 +1087,9 @@ def _apply_rel_filters(self, queryset):
             queryset._add_hints(instance=self.instance)
             if self._db:
                 queryset = queryset.using(self._db)
-            queryset._defer_next_filter = True
-            return queryset._next_is_sticky().filter(**self.core_filters)
+            return queryset._next_is_sticky()._filter_q(
+                Q(**self.core_filters), defer=True
+            )
 
         def get_prefetch_cache(self):
             try:

diff --git a/django/db/models/query.py b/django/db/models/query.py
@@ -291,7 +291,6 @@ def __init__(self, model=None, query=None, using=None, hints=None):
         self._known_related_objects = {}  # {rel_field: {pk: rel_obj}}
         self._iterable_class = ModelIterable
         self._fields = None
-        self._defer_next_filter = False
         self._deferred_filter = None
 
     @property
@@ -1495,12 +1494,11 @@ def exclude(self, *args, **kwargs):
         self._not_support_combined_queries("exclude")
         return self._filter_q(~Q(*args, **kwargs))
 
-    def _filter_q(self, q):
+    def _filter_q(self, q, *, defer=False):
         if q and self.query.is_sliced:
             raise TypeError("Cannot filter a query once a slice has been taken.")
         clone = self._chain()
-        if self._defer_next_filter:
-            self._defer_next_filter = False
+        if defer:
             clone._deferred_filter = q
         else:
             clone.query.add_q(q)

diff --git a/tests/queryset_pickle/tests.py b/tests/queryset_pickle/tests.py
@@ -318,8 +318,7 @@ def test_annotation_values_list(self):
 
     def test_filter_deferred(self):
         qs = Happening.objects.all()
-        qs._defer_next_filter = True
-        qs = qs.filter(id=0)
+        qs = qs._filter_q(models.Q(id=0), defer=True)
         self.assert_pickles(qs)
 
     def test_missing_django_version_unpickling(self):