Prevent transferring files from priv/ to pub/ on event clone (#3956)

* Prevent transferring files from priv/ to pub/ on event clone

* Also detect file names with node prefix

* Only transfer files in explicitly declared file fields

* Update django-hierarkey

* Add note to documentation about the new behaviour

doc/development/implementation/settings.rst

@@ -15,7 +15,7 @@ includes serializers for serializing the following types:
 * Built-in types: ``int``, ``float``, ``decimal.Decimal``, ``dict``, ``list``, ``bool``
 * ``datetime.date``, ``datetime.datetime``, ``datetime.time``
 * ``LazyI18nString``
-* References to Django ``File`` objects that are already stored in a storage backend
+* References to Django ``File`` objects that are already stored in a storage backend [#f1]_
 * References to model instances
 
 In code, we recommend to always use the ``.get()`` method on the settings object to access a value, but for
@@ -55,6 +55,9 @@ You can simply use it like this:
                        "preserve his reservation."),
        )
 
+
+.. _settings-defaults-in-plugins:
+
 Defaults in plugins
 -------------------
 
@@ -70,3 +73,9 @@ Make sure that you include this code in a module that is imported at app loading
 
 .. _django-hierarkey: https://github.com/raphaelm/django-hierarkey
 .. _documentation: https://django-hierarkey.readthedocs.io/en/latest/
+
+.. rubric:: Footnotes
+
+.. [#f1] If you store ``File`` instances in per-event settings, make sure to always register them with ``add_default``
+         as described above in :ref:`settings-defaults-in-plugins`. Otherwise, the file won't get copied properly if the
+         user copies the settings of an existing event to a new one.

pyproject.toml

@@ -43,7 +43,7 @@ dependencies = [
   "django-filter==24.2",
   "django-formset-js-improved==0.5.0.3",
   "django-formtools==2.5.1",
-  "django-hierarkey==1.1.*",
+  "django-hierarkey==1.2.*",
   "django-hijack==3.4.*",
   "django-i18nfield==1.9.*,>=1.9.4",
   "django-libsass==0.9",

src/pretix/base/models/event.py

@@ -45,6 +45,7 @@ from zoneinfo import ZoneInfo
 import pytz_deprecation_shim
 from django.conf import settings
 from django.core.exceptions import ValidationError
+from django.core.files import File
 from django.core.files.storage import default_storage
 from django.core.mail import get_connection
 from django.core.validators import (
@@ -1025,7 +1026,7 @@ class Event(EventMixin, LoggedModel):
 
             s.object = self
             s.pk = None
-            if s.value.startswith('file://'):
+            if s.value.startswith('file://') and settings_hierarkey.get_declared_type(s.key) == File:
                 fi = default_storage.open(s.value[len('file://'):], 'rb')
                 nonce = get_random_string(length=8)
                 fname_base = clean_filename(os.path.basename(s.value))