Ticket #10262: delete_cascade_option_r9832.diff

django/db/models/base.py

@@ -11 +11 @@
 import django.db.models.manager     # Imported to register signal handler.
 from django.core.exceptions import ObjectDoesNotExist, MultipleObjectsReturned, FieldError
 from django.db.models.fields import AutoField, FieldDoesNotExist
-from django.db.models.fields.related import OneToOneRel, ManyToOneRel, OneToOneField
+from django.db.models.fields.related import OneToOneRel, ManyToOneRel, OneToOneField, RelatedObject
 from django.db.models.query import delete_objects, Q, CollectedObjects
 from django.db.models.options import Options
 from django.db import connection, transaction, DatabaseError
@@ -456 +456 @@
     def delete(self):
         assert self._get_pk_val() is not None, "%s object can't be deleted because its %s attribute is set to None." % (self._meta.object_name, self._meta.pk.attname)
 
+        # Clear all related object with delete_cascade=False
+        for field in self._meta.get_all_fields():
+            if isinstance(field, RelatedObject) and not field.field.delete_cascade:
+                related_manager = getattr(self, field.get_accessor_name())
+                related_manager.clear()
+
         # Find all the objects than need to be deleted.
         seen_objs = CollectedObjects()
         self._collect_sub_objects(seen_objs)

django/db/models/options.py

@@ -283 +283 @@
             raise FieldDoesNotExist('%s has no field named %r'
                     % (self.object_name, name))
 
+    def get_all_fields(self):
+        """
+        Returns a list of all fields that are possible for this model
+        (including reverse relation names).
+        """
+        try:
+            cache = self._name_map
+        except AttributeError:
+            cache = self.init_name_map()
+        fields = [ r[0] for r in cache.values() ]
+        return fields
+
     def get_all_field_names(self):
         """
         Returns a list of all field names that are possible for this model

django/db/models/fields/related.py

@@ -646 +646 @@
             limit_choices_to=kwargs.pop('limit_choices_to', None),
             lookup_overrides=kwargs.pop('lookup_overrides', None),
             parent_link=kwargs.pop('parent_link', False))
+
+        self.delete_cascade = kwargs.pop('delete_cascade', True)
+
         Field.__init__(self, **kwargs)
 
         self.db_index = True
+        assert self.null or self.delete_cascade, "%s cannot define a not null relation (null=False) without deleting cascade (delete_cascade=False)" % self.__class__.__name__
 
     def get_attname(self):
         return '%s_id' % self.name