Fixed #6456 - Excised FileField file deletion to avoid data loss. Thanks to durdinator for the report.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15321 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/fields/files.py

@@ -258,19 +258,6 @@ class FileField(Field):
     def contribute_to_class(self, cls, name):
         super(FileField, self).contribute_to_class(cls, name)
         setattr(cls, self.name, self.descriptor_class(self))
-        signals.post_delete.connect(self.delete_file, sender=cls)
-
-    def delete_file(self, instance, sender, **kwargs):
-        file = getattr(instance, self.attname)
-        # If no other object of this type references the file,
-        # and it's not the default value for future objects,
-        # delete it from the backend.
-        if file and file.name != self.default and \
-            not sender._default_manager.filter(**{self.name: file.name}):
-                file.delete(save=False)
-        elif file:
-            # Otherwise, just close the file, so it doesn't tie up resources.
-            file.close()
 
     def get_directory_name(self):
         return os.path.normpath(force_unicode(datetime.datetime.now().strftime(smart_str(self.upload_to))))

docs/releases/1.3.txt

@@ -261,6 +261,20 @@ requests. These include:
 Backwards-incompatible changes in 1.3
 =====================================
 
+FileField no longer deletes files
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+In earlier Django versions, when a model instance containing a
+:class:`~django.db.models.FileField` was deleted,
+:class:`~django.db.models.FileField` took it upon itself to also delete the
+file from the backend storage. This opened the door to several data-loss
+scenarios, including rolled-back transactions and fields on different models
+referencing the same file. In Django 1.3, :class:`~django.db.models.FileField`
+will never delete files from the backend storage. If you need cleanup of
+orphaned files, you'll need to handle it yourself (for instance, with a custom
+management command that can be run manually or scheduled to run periodically
+via e.g. cron).
+
 PasswordInput default rendering behavior
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

tests/modeltests/files/tests.py

@@ -61,11 +61,10 @@ class FileTests(TestCase):
         cache.set("obj2", obj2)
         self.assertEqual(cache.get("obj2").normal.name, "tests/django_test_1.txt")
 
-        # Deleting an object deletes the file it uses, if there are no other
+        # Deleting an object does not delete the file it uses.
-        # objects still using that file.
         obj2.delete()
         obj2.normal.save("django_test.txt", ContentFile("more content"))
-        self.assertEqual(obj2.normal.name, "tests/django_test_1.txt")
+        self.assertEqual(obj2.normal.name, "tests/django_test_2.txt")
 
         # Multiple files with the same name get _N appended to them.
         objs = [Storage() for i in range(3)]