GTS does not support multiple redirect_uris

Author: Your Name

mastodon/api.py

@@ -376,7 +376,10 @@ def get_or_create_fediverse_application(login_domain):
         app = MastodonApplication.objects.filter(domain_name__iexact=domain).first()
         if app:
             return app
-    allow_multiple_redir = True  # TODO detect site supports multiple redirect uris
+    allow_multiple_redir = True
+    if "; Pixelfed" in server_version or server_version.startswith("0."):
+        # Pixelfed and GoToSocial don't support multiple redirect uris
+        allow_multiple_redir = False
     response = create_app(api_domain, allow_multiple_redir)
     if response.status_code != 200:
         logger.error(

mastodon/management/commands/mastodon_sites.py

@@ -2,7 +2,7 @@
 
 from django.core.management.base import BaseCommand
 
-from mastodon.api import create_app
+from mastodon.api import create_app, detect_server_info
 from mastodon.models import MastodonApplication
 
 
@@ -20,7 +20,15 @@ def add_arguments(self, parser):
     def handle(self, *args, **options):
         if options["refresh"]:
             for site in MastodonApplication.objects.exclude(disabled=True):
+                try:
+                    _, _, server_version = detect_server_info(site.api_domain)
+                except Exception:
+                    continue
                 allow_multiple_redir = True
+                if "; Pixelfed" in server_version or server_version.startswith("0."):
+                    allow_multiple_redir = False
+                if allow_multiple_redir:
+                    continue
                 try:
                     response = create_app(site.api_domain, allow_multiple_redir)
                 except Exception as e: