[pull] main from django:main

django/db/models/sql/query.py

@@ -1444,7 +1444,7 @@ def build_lookup(self, lookups, lhs, rhs):
         # DEFAULT_DB_ALIAS isn't nice but it's the best that can be done here.
         # A similar thing is done in is_nullable(), too.
         if (
-            lookup_name == "exact"
+            lookup_name in ("exact", "iexact")
             and lookup.rhs == ""
             and connections[DEFAULT_DB_ALIAS].features.interprets_empty_strings_as_nulls
         ):

docs/internals/contributing/writing-code/unit-tests.txt

@@ -85,7 +85,7 @@ default environments can be seen as follows:
     docs
     isort>=7.0.0
     lint-docs
-    zizmor>=1.16.3
+    zizmor>=1.19.0
 
 Testing other Python versions and database backends
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

docs/releases/6.0.txt

@@ -481,6 +481,12 @@ Miscellaneous
 * The minimum supported version of ``asgiref`` is increased from 3.8.1 to
   3.9.1.
 
+.. currentmodule:: django.db.models
+
+* :meth:`Field.pre_save` may now be called more than once when saving model
+  instances, so custom implementations should be idempotent and free of side
+  effects.
+
 .. _deprecated-features-6.0:
 
 Features deprecated in 6.0

package.json

@@ -9,7 +9,7 @@
     "npm": ">=1.3.0"
   },
   "devDependencies": {
-    "eslint": "^9.36.0",
+    "eslint": "^9.39.1",
     "puppeteer": "^24.22.0",
     "grunt": "^1.6.1",
     "grunt-cli": "^1.5.0",

tests/null_queries/models.py

@@ -7,7 +7,7 @@ class Poll(models.Model):
 
 class Choice(models.Model):
     poll = models.ForeignKey(Poll, models.CASCADE)
-    choice = models.CharField(max_length=200)
+    choice = models.CharField(max_length=200, null=True)
 
 
 # A set of models with an inner one pointing to two outer ones.

tests/null_queries/tests.py

@@ -1,5 +1,5 @@
 from django.core.exceptions import FieldError
-from django.test import TestCase
+from django.test import TestCase, skipUnlessDBFeature
 
 from .models import Choice, Inner, OuterA, OuterB, Poll
 
@@ -44,6 +44,18 @@ def test_none_as_null(self):
         with self.assertRaisesMessage(ValueError, "Cannot use None as a query value"):
             Choice.objects.filter(id__gt=None)
 
+    @skipUnlessDBFeature("interprets_empty_strings_as_nulls")
+    def test_empty_string_is_null(self):
+        p = Poll.objects.create(question="?")
+        c1 = Choice.objects.create(poll=p, choice=None)
+        c2 = Choice.objects.create(poll=p, choice="")
+        cases = [{"choice__exact": ""}, {"choice__iexact": ""}]
+        for lookup in cases:
+            with self.subTest(lookup):
+                self.assertSequenceEqual(
+                    Choice.objects.filter(**lookup).order_by("id"), [c1, c2]
+                )
+
     def test_unsaved(self):
         poll = Poll(question="How?")
         msg = (

tests/requirements/py3.txt

@@ -2,7 +2,7 @@ aiosmtpd >= 1.4.5
 asgiref >= 3.9.1
 argon2-cffi >= 23.1.0
 bcrypt >= 4.1.1
-black >= 25.9.0
+black >= 25.12.0
 docutils >= 0.22
 geoip2 >= 4.8.0
 jinja2 >= 2.11.0

tox.ini

@@ -103,7 +103,7 @@ commands =
 [testenv:zizmor]
 basepython = python3
 usedevelop = false
-deps = zizmor >= 1.16.3
+deps = zizmor >= 1.19.0
 changedir = {toxinidir}
 commands =
     zizmor .