Fix handling of UUIDField for mysql, mariadb and sqlite

guardian/shortcuts.py

@@ -3,25 +3,29 @@
 """
 import warnings
 from collections import defaultdict
+from functools import partial
 from itertools import groupby
 
 from django.apps import apps
 from django.contrib.auth import get_user_model
 from django.contrib.auth.models import Group, Permission
 from django.contrib.contenttypes.models import ContentType
+from django.db import connection
 from django.db.models import Count, Q, QuerySet
 from django.shortcuts import _get_queryset
-from django.db.models.functions import Cast
+from django.db.models.expressions import Value
+from django.db.models.functions import Cast, Replace
 from django.db.models import (
-    IntegerField,
     AutoField,
     BigIntegerField,
+    CharField,
+    ForeignKey,
+    IntegerField,
     PositiveIntegerField,
     PositiveSmallIntegerField,
     SmallIntegerField,
-    ForeignKey
     UUIDField,
-    )
+)
 from guardian.core import ObjectPermissionChecker
 from guardian.ctypes import get_content_type
 from guardian.exceptions import MixedContentTypeError, WrongAppError, MultipleIdentityAndObjectError
@@ -624,26 +628,21 @@ def get_objects_for_user(user, perms, klass=None, use_groups=True, any_perm=Fals
     field_pk = user_fields[0]
     values = user_obj_perms_queryset
 
-    cast_pk_field = _cast_pk_field(queryset)
-
-    if cast_pk_field:
-        values = values.annotate(
-            obj_pk=Cast(field_pk, cast_pk_field())
-        )
+    handle_pk_field = _handle_pk_field(queryset)
+    if handle_pk_field is not None:
+        values = values.annotate(obj_pk=handle_pk_field(expression=field_pk))
         field_pk = 'obj_pk'
 
     values = values.values_list(field_pk, flat=True)
-    q = Q(pk__in=list(values))
+    q = Q(pk__in=values)
     if use_groups:
         field_pk = group_fields[0]
         values = groups_obj_perms_queryset
-        if cast_pk_field:
-            values = values.annotate(
-                obj_pk=Cast(field_pk, cast_pk_field())
-            )
+        if handle_pk_field is not None:
+            values = values.annotate(obj_pk=handle_pk_field(expression=field_pk))
             field_pk = 'obj_pk'
         values = values.values_list(field_pk, flat=True)
-        q |= Q(pk__in=list(values))
+        q |= Q(pk__in=values)
 
     return queryset.filter(q)
 
@@ -791,23 +790,20 @@ def get_objects_for_group(group, perms, klass=None, any_perm=False, accept_globa
     field_pk = fields[0]
     values = groups_obj_perms_queryset
 
-    cast_pk_field = _cast_pk_field(queryset)
-
-    if cast_pk_field:
-        values = values.annotate(
-            obj_pk=Cast(field_pk, cast_pk_field())
-        )
+    handle_pk_field = _handle_pk_field(queryset)
+    if handle_pk_field is not None:
+        values = values.annotate(obj_pk=handle_pk_field(expression=field_pk))
         field_pk = 'obj_pk'
 
     values = values.values_list(field_pk, flat=True)
     return queryset.filter(pk__in=values)
 
 
-def _cast_pk_field(queryset):
+def _handle_pk_field(queryset):
     pk = queryset.model._meta.pk
 
     if isinstance(pk, ForeignKey):
-        return _cast_pk_field(pk.target_field)
+        return _handle_pk_field(pk.target_field)
 
     if isinstance(
         pk,
@@ -820,9 +816,16 @@ def _cast_pk_field(queryset):
             SmallIntegerField,
         ),
     ):
-        return BigIntegerField
+        return partial(Cast, output_field=BigIntegerField())
 
     if isinstance(pk, UUIDField):
-        return UUIDField
+        if connection.features.has_native_uuid_field:
+            return partial(Cast, output_field=UUIDField())
+        return partial(
+            Replace,
+            text=Value('-'),
+            replacement=Value(''),
+            output_field=CharField(),
+        )
 
     return None