Uploading a xz file as Binary content crashes moin

[sebix]

1. Go to a non-existing page
2. Select content type Binary File
3. Upload a xz-file
4. Get an Internal Server Error

Traceback:

2025-12-08 13:13:29,949 ERROR moin:875 Exception on /+modify/Test [POST]
Traceback (most recent call last):
  File "/home/user/dev/moin-venv-python3/lib64/python3.13/site-packages/flask/app.py", line 1511, in wsgi_app
    response = self.full_dispatch_request()
  File "/home/user/dev/moin-venv-python3/lib64/python3.13/site-packages/flask/app.py", line 919, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/home/user/dev/moin-venv-python3/lib64/python3.13/site-packages/flask/app.py", line 917, in full_dispatch_request
    rv = self.dispatch_request()
  File "/home/user/dev/moin-venv-python3/lib64/python3.13/site-packages/flask/app.py", line 902, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)  # type: ignore[no-any-return]
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^
  File "/home/user/dev/moin/src/moin/apps/frontend/views.py", line 923, in modify_item
    ret = item.do_modify(item_may=item_may)
  File "/home/user/dev/moin/src/moin/items/__init__.py", line 1679, in do_modify
    self.modify(meta, data, comment, contenttype_guessed, **{CONTENTTYPE: contenttype_qs})
    ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/dev/moin/src/moin/items/__init__.py", line 972, in modify
    return self._save(meta, data, contenttype_guessed=contenttype_guessed, comment=comment)
           ~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/dev/moin/src/moin/items/__init__.py", line 1146, in _save
    charset = meta[CONTENTTYPE].split("charset=")[1]
              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^
IndexError: list index out of range

On version 2.0.0b4-102-g3388bc6b

[roland-ruedenauer]

I'm preparing a fix.