[LOG4J2-2992] PatternParser.parse() ignores nested Patterns when determining if a Throwable should be appended.

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.13.1
• Component/s: Pattern Converters
• Assignee: Unassigned
• Reporter: Nate
• Created: 06/Jan/21 15:07
• Updated: 06/Jan/21 15:07

Description

Simplified example:

%replace{%ex{full}}

{password}

{******}

In this example, PatternParser.parse() only considers the %replace{} converter and does not find the %ex inside. In this case, if the PatternLayout doesn't declare alwaysWriteExceptions="false", it will append an ThrowablePatternConverter anyway, leading to the exception being logged a second time without replace converter processing. It would probably be better if the RegexReplacementConverter (and other converters that support nested patterns) also implements the handlesThrowable() method in a way that delegates this handling to the nested patterns.