Hello Steffen Terheiden,

I have good news, and less good news. Good news is, we completely agree on the contract violation, the fix is undergoing peer-review and will be released soon.
Less good news is, we can't reproduce the issue. In fact, this code should never be called and is not maintained: it probably was forgotten in a previous refactoring, but it is theoretically useless, since text analysis is never performed before serialization (so there never is a token stream to serialize in the first place).

What it means right now is that you can try out the fix, but you'll probably run into other problems anyway ( HSEARCH-2383 Closed comes to mind). If you do run into other issues, we'll need a test case to help you, or at least any information on exotic stuff you might be doing in your application (any use of org.apache.lucene.document.Field.setTokenStream(TokenStream) or org.apache.lucene.document.Field.setReaderValue(Reader) in particular).

You can find test case templates here: https://github.com/hibernate/hibernate-test-case-templates/tree/master/search
In your case, the hibernate-search-lucene project is what you need. If you do decide to create a test case, feel free to ask us for help!