Multiple Select List values are not correctly indexed by Lucene

Steps to reproduce :

1. Create a class Space.C with a property P of type Database List and check the following fields : Multiselect and Relational Storage
2. Add an object of type Space.C to document D
3. Select value V for the property P
4. Save the document
5. Search with Lucene : +Space.C.P:V (you can use (V) if you want, but the result is going to be the same)

Expected result : document D
Real result : no document

The reason why the result is not correct is the fact that Lucene indexes such a property value as String which results in something like : 'com.xpn.xwiki.objects.ListProperty$NotifyList@...' .