stages/user_write: handle integrity error

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

authentik/stages/user_write/stage.py

@@ -2,6 +2,7 @@
 from django.contrib import messages
 from django.contrib.auth import update_session_auth_hash
 from django.contrib.auth.backends import ModelBackend
+from django.db.utils import IntegrityError
 from django.http import HttpRequest, HttpResponse
 from django.utils.translation import gettext as _
 from structlog.stdlib import get_logger
@@ -84,7 +85,11 @@ class UserWriteStageView(StageView):
                 PLAN_CONTEXT_SOURCES_CONNECTION
             ]
             user.attributes[USER_ATTRIBUTE_SOURCES].append(connection.source.name)
-        user.save()
+        try:
+            user.save()
+        except IntegrityError as exc:
+            LOGGER.warning("Failed to save user", exc=exc)
+            self.executor.stage_invalid()
         user_write.send(
             sender=self, request=request, user=user, data=data, created=user_created
         )