[LOG4J2-3289] log4j-to-slf4j should not re-format the result of Message.getFormattedMessage

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.17.0
• Fix Version/s: 2.17.1
• Component/s: SLF4J Bridge
• Assignee: Carter Kozak
• Reporter: Carter Kozak
• Created: 25/Dec/21 16:46
• Updated: 28/Jul/22 20:24
• Resolved: 25/Dec/21 19:20

Description

Both the formatted message result (for the configured MessageFactory) and the parameter array are passed to slf4j, such that slf4j attempts to format the already formatted result:

https://github.com/apache/logging-log4j2/blob/20f9a97dbe5928c3b5077bcdd2a22ac92e941655/log4j-to-slf4j/src/main/java/org/apache/logging/slf4j/SLF4JLogger.java#L226-L256

Caught a similar issue while reviewing this change, but realized it also applies to the slf4j bridge: https://github.com/apache/logging-log4j2/pull/653#discussion_r775083351

Issue Links

• is duplicated by: LOG4J2-2623 log4j-to-slf4j: Messages are formatted twice if there happen to be a `{}` in the parameters
• links to: GitHub Pull Request #659