logstash/logstash — pull request #253 by ru2nuts (2012-11-29 01:19:55+00:00)
Title: fixing log4j.rb Java stacktrace reading - must call to_a before join

Log4J's
LoggingEvent.getThrowableStrRep returns String[], which in not a ruby array. Calling "join" on it resulted in error. Fixed by adding a call to "to_a".