Add allauth_oauth app to sync user fields on OAuth login

allauth_oauth/apps.py

@@ -0,0 +1,12 @@
+# This file is part of photo21
+# Copyright (C) 2022  Amicale des élèves de l'ENS Paris-Saclay
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from django.apps import AppConfig
+
+
+class AllauthOAuthConfig(AppConfig):
+    name = "allauth_oauth"
+
+    def ready(self):
+        import allauth_oauth.signals  # noqa: F401

allauth_oauth/signals.py

@@ -0,0 +1,29 @@
+# This file is part of photo21
+# Copyright (C) 2022  Amicale des élèves de l'ENS Paris-Saclay
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from allauth.socialaccount.signals import pre_social_login
+from django.dispatch import receiver
+
+
+@receiver(pre_social_login)
+def sync_user_fields(sender, request, sociallogin, **kwargs):
+    if not sociallogin.is_existing:
+        return
+
+    user = sociallogin.user
+    data = sociallogin.account.extra_data
+    changed = False
+
+    email = data.get("email")
+    if email and user.email != email:
+        user.email = email
+        changed = True
+
+    username = data.get("username")
+    if username and user.username != username:
+        user.username = username
+        changed = True
+
+    if changed:
+        user.save()