convert userid and recovery email to lowercase to avoid problems like Purism/LibremOne/task#357

cart/views.py

@@ -69,6 +69,9 @@ class CartRegistrationForm(RegistrationForm):
         super(CartRegistrationForm, self).__init__(*args, **kwargs)
         self.fields['username'].validators.append(validate_reserved_names)
 
+    def clean_email(self):
+        return self.cleaned_data['email'].lower()
+
 
 class CartRegistrationFormWithCaptcha(CartRegistrationForm):
     captcha = CaptchaField(

purist/models.py

@@ -88,6 +88,10 @@ class User(AbstractUser):
                                     default=AccountType.UNDEFINED)
     billing_email = models.EmailField(default='', null=False)
 
+    def clean(self):
+        super().clean()
+        self.email = self.email.lower()
+
     @classmethod
     def normalize_username(cls, username):
         username = super(User, cls).normalize_username(username)