NPE: JdbcDataSource should handle null ResultSet

SCHWERWIEGEND: Full Import failed:org.apache.solr.handler.dataimport.DataImportHandlerException: Unable to execute query: DELETE FROM SOLR_EXPERIMENT_OPERATION WHERE CREATION_DATE < TO_DATE('2012.04.25, 12:58:59','YYYY.MM.DD, HH:MI:SS') Processing Document # 1
        at org.apache.solr.handler.dataimport.DataImportHandlerException.wrapAndThrow(DataImportHandlerException.java:72)
        at org.apache.solr.handler.dataimport.JdbcDataSource$ResultSetIterator.<init>(JdbcDataSource.java:253)
        at org.apache.solr.handler.dataimport.JdbcDataSource.getData(JdbcDataSource.java:210)
        at org.apache.solr.handler.dataimport.JdbcDataSource.getData(JdbcDataSource.java:39)
        at com.bayer.bcl.solr.dih.listener.RemoveObsoleteReferencesListener.onEvent(RemoveObsoleteReferencesListener.java:38)
        at org.apache.solr.handler.dataimport.DocBuilder.notifyListener(DocBuilder.java:135)
        at org.apache.solr.handler.dataimport.DocBuilder.invokeEventListener(DocBuilder.java:122)
        at org.apache.solr.handler.dataimport.DocBuilder.execute(DocBuilder.java:217)
        at org.apache.solr.handler.dataimport.DataImporter.doFullImport(DataImporter.java:359)
        at org.apache.solr.handler.dataimport.DataImporter.runCmd(DataImporter.java:427)
        at org.apache.solr.handler.dataimport.DataImporter$1.run(DataImporter.java:408)
Caused by: java.lang.NullPointerException
        at org.apache.solr.handler.dataimport.JdbcDataSource$ResultSetIterator.<init>(JdbcDataSource.java:251)
        ... 9 more