Copying corpus sometimes fails

[jerneju]

Text version

Current (~0.2.5) and older

Orange version

master

Expected behavior

corpus = Corpus(...)
new_corpus = corpus.copy()

That should work and not raise an error.

Actual behavior

orangecontrib.text.corpus in set_text_features at line 90
raise ValueError('Feature "{}" not found.'.format(f))
orangecontrib.text.corpus in init at line 73
self.set_text_features(text_features)
orangecontrib.text.corpus in copy at line 321
self.W.copy(), copy(self.text_features))
orangecontrib.text.widgets.owpreprocess in set_data at line 598
self.corpus = data.copy() if data is not None else None

https://sentry.io/biolab/orange3-text-bl/issues/399242697/

Steps to reproduce the behavior

Additional info (worksheets, data, screenshots, ...)

[jerneju]

data.transform(new_domain) does not update text_features.

[nikicc]

Could you fix transform on Corpus to retain them?

[jerneju]

Yes.