Empty OAI-PMH list of sets?

[stweil]

I have a test installation which returns the error noSetHierarchy for http://HOST/oai?verb=ListSets although several documents with sets were indexed and ListIdentifiers shows these documents with their correct setSpec entries.

[stweil]

If I restrict ListIdentifier to one of the existing sets – for example http://HOST/oai?verb=ListIdentifiers&metadataPrefix=oai_dc&set=open_access – I get the error idDoesNotExist. It also says "Der im Parameter "identifier" angegebene Wert existiert nicht im Repository.", but there is no parameter identifier. This is a bug, because the error code idDoesNotExist is not expected for ListIdentifiers. Older releases returned noSetHierarchy which is correct, so this is a regression.