[LOG4J2-3247] PropertiesConfiguration.parseAppenderFilters NPE when parsing properties file filters

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 2.16.0
• Fix Version/s: 2.17.1
• Component/s: Configurators
• Assignee: Unassigned
• Reporter: Fábio Constantino
• Created: 16/Dec/21 18:27
• Updated: 23/Dec/21 13:39
• Resolved: 16/Dec/21 23:08

Description

When parsing appender filters configured in the properties file for example:

log4j.appender.LOG_REQUEST_START_DB=my.appender.class
log4j.appender.LOG_REQUEST_START_DB.filter.ID=my.filter.class

a NullPointerException is thrown on line 564 of org.apache.log4j.config.PropertiesConfiguration. The next variable is always null at that point, from what appears to be a bug in the if condition above (looks like it should be head == null instead of head != null).

 

Note: this is using the log4j1.compatibility=true property