[LOG4J2-3131] Attempting to call getExtendedStackTraceAsString() after deserializing JSON LogEvent results in a NPE

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.14.1
• Fix Version/s: 3.0.0, 2.15.0
• Component/s: Layouts
• Assignee: Gary D. Gregory
• Reporter: Adam Long
• Created: 27/Jul/21 17:34
• Updated: 29/Jul/21 12:40
• Resolved: 29/Jul/21 12:40

Description

How to reproduce:

1. Generate a LogEvent with an Exception that has at least one cause (i.e. nested Exception)
2. Use the standard JSON Layout to turn that LogEvent into JSON
3. Using JsonLogEventParser to turn it back into a LogEvent
4. Call getExtendedStackTraceAsString() on the ThrowableProxy associated with the deserialized LogEvent
5. A NullPointerException will be thrown

I've attached a small example project to reproduce the error.