Description
When repeatedly killed and started up again, jackrabbit may throw an IllegalArgumentException on index recovery:
Caused by: java.lang.IllegalArgumentException: already contains: _c
at org.apache.jackrabbit.core.query.lucene.IndexInfos.addName(IndexInfos.java:170)
at org.apache.jackrabbit.core.query.lucene.MultiIndex.deleteIndex(MultiIndex.java:716)
at org.apache.jackrabbit.core.query.lucene.MultiIndex$DeleteIndex.execute(MultiIndex.java:1553)
at org.apache.jackrabbit.core.query.lucene.MultiIndex.executeAndLog(MultiIndex.java:809)
at org.apache.jackrabbit.core.query.lucene.MultiIndex.flush(MultiIndex.java:740)
at org.apache.jackrabbit.core.query.lucene.Recovery.run(Recovery.java:160)