symptom: full-text index not getting updated.

cause: infinite loop in SearchableThingTextExtractor

Exception in thread "Timer-0" java.lang.StackOverflowError
at java.lang.Class.getMethod0(Class.java:2687)
at java.lang.Class.getMethod(Class.java:1620)
at org.apache.commons.logging.LogFactory.directGetContextClassLoader(LogFactory.java:896)
at org.apache.commons.logging.LogFactory$1.run(LogFactory.java:862)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.commons.logging.LogFactory.getContextClassLoaderInternal(LogFactory.java:859)
at org.apache.commons.logging.LogFactory.getFactory(LogFactory.java:423)
at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:685)
at org.tupeloproject.kernel.Context.<init>(Context.java:33)
at org.tupeloproject.kernel.BaseContext.<init>(BaseContext.java:29)
at org.tupeloproject.kernel.impl.MemoryContext.<init>(MemoryContext.java:424)
at org.tupeloproject.kernel.impl.MemoryContext.<init>(MemoryContext.java:442)
at org.tupeloproject.kernel.SubjectSession.fetchSubject(SubjectSession.java:113)
at org.tupeloproject.kernel.SubjectSession.getSubject(SubjectSession.java:141)
at org.tupeloproject.kernel.SubjectSession.getValues(SubjectSession.java:472)
at org.tupeloproject.kernel.Thing.getValues(Thing.java:515)
at org.tupeloproject.kernel.Thing.getTypes(Thing.java:169)
at org.tupeloproject.kernel.Thing.hasType(Thing.java:859)
at org.tupeloproject.kernel.beans.things.BeanThing.<init>(BeanThing.java:64)
at org.tupeloproject.kernel.beans.things.BeanThing.createBeanThing(BeanThing.java:55)
at org.tupeloproject.kernel.beans.BeanSessionImpl.fetchBean(BeanSessionImpl.java:715)
at org.tupeloproject.kernel.beans.things.BeanSerializationStrategy.fetchInstance(BeanSerializationStrategy.java:110)
at org.tupeloproject.kernel.beans.things.BeanThing.convertValue(BeanThing.java:745)
at org.tupeloproject.kernel.beans.things.BeanThing.getScalarValue(BeanThing.java:562)
at org.tupeloproject.kernel.beans.things.BeanThing.getValue(BeanThing.java:504)
at org.tupeloproject.kernel.beans.things.BeanThing.deserialize(BeanThing.java:161)
at org.tupeloproject.kernel.beans.things.BeanThing.deserialize(BeanThing.java:102)
at org.tupeloproject.kernel.beans.things.BeanThing.deserialize(BeanThing.java:98)
at org.tupeloproject.kernel.beans.BeanSessionImpl.fetchBean(BeanSessionImpl.java:595)
at org.tupeloproject.kernel.beans.BeanSessionImpl.fetchBean(BeanSessionImpl.java:625)
at edu.illinois.ncsa.mmdb.web.server.search.SearchableThingTextExtractor.fetchBean(SearchableThingTextExtractor.java:91)
at edu.illinois.ncsa.mmdb.web.server.search.SearchableThingTextExtractor.authors(SearchableThingTextExtractor.java:166)
at edu.illinois.ncsa.mmdb.web.server.search.SearchableThingTextExtractor.authors(SearchableThingTextExtractor.java:159)
at edu.illinois.ncsa.mmdb.web.server.search.SearchableThingTextExtractor.authors(SearchableThingTextExtractor.java:168)
at edu.illinois.ncsa.mmdb.web.server.search.SearchableThingTextExtractor.authors(SearchableThingTextExtractor.java:159)
at edu.illinois.ncsa.mmdb.web.server.search.SearchableThingTextExtractor.authors(SearchableThingTextExtractor.java:168)