more Django 4.1 fixes

categories/management/commands/add_category_fields.py

@@ -10,7 +10,7 @@ class Command(BaseCommand):
     help = "Alter the tables for all registered models, or just specified models"
     args = "[appname ...]"
     can_import_settings = True
-    requires_system_checks = False
+    requires_system_checks = []
 
     def add_arguments(self, parser):
         """Add app_names argument to the command."""

categories/management/commands/drop_category_field.py

@@ -10,7 +10,7 @@ class Command(BaseCommand):
     help = "Drop the given field from the given model's table"
     args = "appname modelname fieldname"
     can_import_settings = True
-    requires_system_checks = False
+    requires_system_checks = []
 
     def add_arguments(self, parser):
         """Add app_name, model_name, and field_name arguments to the command."""

categories/migration.py

@@ -1,7 +1,7 @@
 """Adds and removes category relations on the database."""
 from django.apps import apps
 from django.db import DatabaseError, connection, transaction
-from django.db.utils import ProgrammingError
+from django.db.utils import OperationalError, ProgrammingError
 
 
 def table_exists(table_name):
@@ -71,7 +71,9 @@ def migrate_app(sender, *args, **kwargs):
                 schema_editor.add_field(model, registry._field_registry[fld])
                 if sid:
                     transaction.savepoint_commit(sid)
-        except ProgrammingError:
+        # Django 4.1 with sqlite3 has for some reason started throwing OperationalError
+        # instead of ProgrammingError, so we need to catch both.
+        except (ProgrammingError, OperationalError):
             if sid:
                 transaction.savepoint_rollback(sid)
             continue