[LOG4J2-1583] Nested logging call disrupts output of outer logging call

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.6, 2.6.1, 2.6.2
• Fix Version/s: 2.7
• Component/s: Core

Environment

JVM 1.8.0_102, MacOS 10.11.6

• Epic Link: GC-free
• Assignee: Remko Popma
• Reporter: Larry West
• Created: 14/Sep/16 23:54
• Updated: 18/Sep/16 10:42
• Resolved: 17/Sep/16 13:06

Description

If a call to logger.info() invokes the toString() method on one of its parameters, and that toString() method invokes another method which has another, nested logging call, then the output of the outer call is mangled.

This can be quite confusing as the nested logging may be conditional, or at DEBUG level, etc.

Problem appears to be related to ReusableParameterizedMessage.swapMessage() and the values in indices[]. (It looks inherently non-reentrant.)