[QUESTIION]:immediateFlush and bufferedIO cut into two parts

[7y-9]

When using log4j2, we found that the last log file was always part of a log, which configuration caused this situation.
Thanks.

[vy]

@7y-9, as a start, could you verify that the issue persists with the latest Log4j version, that is, 2.22.1?

If upgrading to the latest Log4j version doesn't fix the issue, to help us reproduce the problem, could you provide the following, please?

1. A minimal log4j2.xml
2. A minimal Test.java
3. Description of what you were expecting
4. Description of what has actually happened