Make usernames case-insensitive.

drakul/users/models.py

@@ -1,4 +1,5 @@
 from django.contrib.auth.models import AbstractUser
+from django.contrib.auth.models import UserManager as DjangoUserManager
 from django.core.exceptions import ValidationError
 from django.core.validators import RegexValidator, MinLengthValidator
 from django.db import models, transaction
@@ -20,6 +21,11 @@ class Rank(models.Model):
         return self.name
 
 
+class UserManager(DjangoUserManager):
+    def get_by_natural_key(self, username):
+        return super().get_by_natural_key(self.model.normalize_username(username))
+
+
 class User(AbstractUser):
     first_name = None
     last_name = None
@@ -37,15 +43,25 @@ class User(AbstractUser):
         blank=True
     )
 
+    objects = UserManager()
+
     class Meta:
         ordering = ["rank", "username"]
 
     def clean(self):
+        self.username = self.normalize_username(self.username)
         if not hasattr(self, "rank"):
             self.rank = Rank.objects.last()
         if hasattr(self, "main") and self.main.user != self:
             raise ValidationError({"main": "Main character must be owned by user."})
 
+    @classmethod
+    def normalize_username(cls, username):
+        """
+        Make username case-insensitive.
+        """
+        return super().normalize_username(username).lower()
+
     @transaction.atomic
     def save(self, *args, **kwargs):
         if not hasattr(self, "main"):