A new file security checkup in Django 2.2.21 throws SuspiciousFileOperation.

For reference see:
https://docs.djangoproject.com/en/dev/releases/2.2.21/
django/django@04ac162

Django now prevents empty file name:

# Remove potentially dangerous names if name in {'', '.', '..'}: raise SuspiciousFileOperation("Could not derive file name from '%s'" % name)

The class ChunkedUploadView initializes the file with an empty name:

def create_chunked_upload(self, save=False, **attrs): """ Creates new chunked upload instance. Called if no 'upload_id' is found in the POST data. """ chunked_upload = self.model(**attrs) # file starts empty chunked_upload.file.save(name='', content=ContentFile(''), save=save) return chunked_upload

The name needs to be changed to something not empty to fix this issue.

Until this issue is fixed, it is possible to override create_chunked_upload with a custom class:

`
class MyChunkedUploadView(ChunkedUploadView):
"""
This view receives the posted chunk
"""

model = ChunkedUploadedFile
field_name = 'the_file'

def create_chunked_upload(self, save=False, **attrs):
    """
    Creates new chunked upload instance. Called if no 'upload_id' is
    found in the POST data.
    """
    chunked_upload = self.model(**attrs)
    # file starts empty
    chunked_upload.file.save(name='tmp', content=ContentFile(''), save=save)
    return chunked_upload`