[LOG4J2-2123] logger filter in composite logger not combined properly

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.11.0
• Assignee: Unassigned
• Reporter: Jacob Tolar
• Created: 21/Nov/17 18:05
• Updated: 11/Dec/17 20:59
• Resolved: 11/Dec/17 05:47

Description

When using a composite logger with DefaultMergeStrategy, logger filters aren't combined properly.

Specifically, if the 'parent' configuration for the logger has no filter and the child configuration does, all attributes and children of the child filter are dropped from the composite configuration.

For example, if my parent logger has:

    <Loggers>
        <Logger name="cat1" level="debug" additivity="false">
            <AppenderRef ref="File"/>
        </Logger>

and the child logger has:

    <Loggers>
        <Logger name="cat1" level="debug" additivity="false">
            <RegexFilter regex=".*TEST.*" onMatch="DENY" onMismatch="ACCEPT" />
            <AppenderRef ref="File"/>
        </Logger>

DefaultMergeStrategy creates a RegexFilter node in the composite configuration with no attributes. You end up getting a message like this when the RegexFilter is constructed:

2017-11-21 12:02:26,733 main ERROR A regular expression must be provided for RegexFilter

Here: https://github.com/apache/logging-log4j2/blob/master/log4j-core/src/main/java/org/apache/logging/log4j/core/config/composite/DefaultMergeStrategy.java#L172-L174

A new copy of the filter node is created, but the children and attributes aren't added to the new nodes.

If the parent logger config does have a filter, it looks like it works correctly.

Issue Links

• links to: GitHub Pull Request #135