Fix saving preprint without _id

osf/models/mixins.py

@@ -30,6 +30,7 @@
 )
 from osf.models.notification_type import NotificationTypeEnum
 from osf.models.notification_subscription import NotificationSubscription
+from .base import VersionedGuidMixin
 from .node_relation import NodeRelation
 from .nodelog import NodeLog
 from .subject import Subject
@@ -1908,6 +1909,16 @@ def remove_contributor(self, contributor, auth, log=True, _force=False):
                 save=False,
             )
 
+        if isinstance(self, VersionedGuidMixin) and not self._id:
+            # Legacy/un-migrated versioned resources can't be saved -- Preprint.save() requires a
+            # valid _id. The contributor row is already removed above; there's
+            # nothing else to persist, so skip save + downstream signals.
+            logger.info(
+                f'Skipping save on {self.__class__.__name__} (pk={self.pk}) in remove_contributor: '
+                'resource has no valid _id.'
+            )
+            return True
+
         self.save()
         # send signal to remove this user from project subscriptions
         project_signals.contributor_removed.send(self, user=contributor)

osf_tests/test_user.py

@@ -27,6 +27,7 @@
 from osf.models import (
     AbstractNode,
     OSFUser,
+    Preprint,
     Tag,
     Contributor,
     NotableDomain,
@@ -2135,6 +2136,14 @@ def project_with_two_admins(self, user):
         project.save()
         return project
 
+    @pytest.fixture()
+    def preprint_with_two_admins(self, user):
+        second_admin_contrib = UserFactory()
+        preprint = PreprintFactory(creator=user)
+        preprint.add_contributor(second_admin_contrib, permissions=permissions.ADMIN)
+        preprint.save()
+        return preprint
+
     @pytest.fixture()
     def project_with_two_admins_and_addon_credentials(self, user):
         second_admin_contrib = UserFactory()
@@ -2338,6 +2347,16 @@ def test_can_gdpr_delete_shared_node_without_guid(self, user, project_with_two_a
 
         assert user.nodes.all().count() == 0
 
+    def test_can_gdpr_delete_shared_preprint_without_guid(self, user, preprint_with_two_admins):
+        preprint_with_two_admins.versioned_guids.all().delete()
+        preprint = Preprint.objects.get(pk=preprint_with_two_admins.pk)
+        assert preprint._id is None
+
+        with override_flag(ENABLE_GV, active=True):
+            user.gdpr_delete()
+
+        assert user.preprints.all().count() == 0
+
     def test_cant_gdpr_delete_with_addon_credentials(self, user, project_with_two_admins_and_addon_credentials):
 
         with pytest.raises(UserStateError) as exc_info: