add shredder mixins

src/pretix/base/models/log.py

@@ -323,3 +323,13 @@ class TaxRuleLogEntryType(EventLogEntryType):
     object_link_wrapper = _('Tax rule {val}')
     object_link_viewname = 'control:event.settings.tax.edit'
     object_link_argname = 'rule'
+
+
+class NoOpShredderMixin:
+    def shred_pii(self, logentry):
+        pass
+
+
+class ClearDataShredderMixin:
+    def shred_pii(self, logentry):
+        logentry.data = None

src/pretix/plugins/banktransfer/signals.py

@@ -29,6 +29,7 @@ from pretix.base.models.log import OrderLogEntryType, log_entry_types
 from pretix.base.signals import register_payment_providers
 from pretix.control.signals import html_head, nav_event, nav_organizer
 
+from ...base.models.log import ClearDataShredderMixin
 from ...base.settings import settings_hierarkey
 from .payment import BankTransfer
 
@@ -119,7 +120,7 @@ def html_head_presale(sender, request=None, **kwargs):
 
 
 @log_entry_types.new()
-class BanktransferOrderEmailInvoiceLogEntryType(OrderLogEntryType):
+class BanktransferOrderEmailInvoiceLogEntryType(OrderLogEntryType, ClearDataShredderMixin):
     action_type = 'pretix.plugins.banktransfer.order.email.invoice'
     plain = _('The invoice was sent to the designated email address.')