Fixed #35384 -- Raised FieldError when saving a file without a name to FileField.

django/db/models/fields/files.py

@@ -3,7 +3,8 @@ import posixpath
 
 from django import forms
 from django.core import checks
-from django.core.files.base import File
+from django.core.exceptions import FieldError
+from django.core.files.base import ContentFile, File
 from django.core.files.images import ImageFile
 from django.core.files.storage import Storage, default_storage
 from django.core.files.utils import validate_file_name
@@ -12,6 +13,7 @@ from django.db.models.fields import Field
 from django.db.models.query_utils import DeferredAttribute
 from django.db.models.utils import AltersData
 from django.utils.translation import gettext_lazy as _
+from django.utils.version import PY311
 
 
 class FieldFile(File, AltersData):
@@ -312,6 +314,15 @@ class FileField(Field):
 
     def pre_save(self, model_instance, add):
         file = super().pre_save(model_instance, add)
+        if file.name is None and file._file is not None:
+            exc = FieldError(
+                f"File for {self.name} must have "
+                "the name attribute specified to be saved."
+            )
+            if PY311 and isinstance(file._file, ContentFile):
+                exc.add_note("Pass a 'name' argument to ContentFile.")
+            raise exc
+
         if file and not file._committed:
             # Commit the file to storage prior to saving the model
             file.save(file.name, file.file, save=False)

docs/releases/5.1.txt

@@ -425,6 +425,10 @@ Miscellaneous
 
 * The minimum supported version of SQLite is increased from 3.27.0 to 3.31.0.
 
+* :class:`~django.db.models.FileField` now raises a
+  :class:`~django.core.exceptions.FieldError` when saving a file without a
+  ``name``.
+
 .. _deprecated-features-5.1:
 
 Features deprecated in 5.1

tests/model_fields/test_filefield.py

@@ -5,13 +5,14 @@ import tempfile
 import unittest
 from pathlib import Path
 
-from django.core.exceptions import SuspiciousFileOperation
+from django.core.exceptions import FieldError, SuspiciousFileOperation
 from django.core.files import File, temp
 from django.core.files.base import ContentFile
 from django.core.files.uploadedfile import TemporaryUploadedFile
 from django.db import IntegrityError, models
 from django.test import TestCase, override_settings
 from django.test.utils import isolate_apps
+from django.utils.version import PY311
 
 from .models import Document
 
@@ -72,6 +73,27 @@ class FileFieldTests(TestCase):
             with self.assertRaisesMessage(SuspiciousFileOperation, msg):
                 document.save()
 
+    def test_save_content_file_without_name(self):
+        d = Document()
+        d.myfile = ContentFile(b"")
+        msg = "File for myfile must have the name attribute specified to be saved."
+        with self.assertRaisesMessage(FieldError, msg) as cm:
+            d.save()
+
+        if PY311:
+            self.assertEqual(
+                cm.exception.__notes__, ["Pass a 'name' argument to ContentFile."]
+            )
+
+    def test_delete_content_file(self):
+        file = ContentFile(b"", name="foo")
+        d = Document.objects.create(myfile=file)
+        d.myfile.delete()
+        self.assertIsNone(d.myfile.name)
+        msg = "The 'myfile' attribute has no file associated with it."
+        with self.assertRaisesMessage(ValueError, msg):
+            getattr(d.myfile, "file")
+
     def test_defer(self):
         Document.objects.create(myfile="something.txt")
         self.assertEqual(Document.objects.defer("myfile")[0].myfile, "something.txt")