MDCContextMap::getCopy can return null causing an NPE in CloseableThreadContext

[jvz]

Description

MDCContextMap::getCopy delegates to MDC::getCopyOfContextMap which is documented as potentially returning null. This fact is respected within MDCContextMap, but ThreadContextMap::getCopy is documented as returning a non-null value. In CloseableThreadContext.Instance, this causes NullPointerExceptions in the putAll method when ThreadContext::getContext is invoked and later used.

Configuration

Version: 2.20.0

Operating system: [OS and version]

JDK: [JDK distribution and version]

Logs

java.lang.NullPointerException: null
        at org.apache.logging.log4j.CloseableThreadContext$Instance.putAll(CloseableThreadContext.java:170)
        at org.apache.logging.log4j.CloseableThreadContext.putAll(CloseableThreadContext.java:100)

Reproduction

[An isolated test reproducing the test.
JUnit tests similar to the ones in the code base are extremely appreciated.]

[benkeil]

any news on this?

[ppkarwasz]

@benkeil,

Can you provide a PR?