When appenders are defined in multiple levels of the logger hierarchy, corruption of the log output occurs.
To illustrate, create a log4cxx.properties file wih the following loggers defined:
'apndr1' and 'apndr2' can be any type of appender, although for the purposes of investigating this bug, FileAppenders and RollingFileAppenders were used with PatternLayout and XMLLayout layouts.
Once configured, using multiple threads to create a heavy load on the logging system, send log events to the 'subLogger' logger.
Some of the data in the resulting logging output will include garbage.