I have made the change you suggested, creating a new list and simply amending to minimize the diff. This new patch has been attached.

I looked through the rest of database.py and did not see any other generators that appeared to erroneously hold a file handle open. If you are able to identify one that actually is a problem I would be happy to change it.

In addition there is one generator function (list_distinfo_files) which feeds off of the generator I have changed but I didn't see a need to alter them as they work fine as generators.