ArrayIndexOutOfBoundsException on invocation of org.apache.logging.log4j.message.Message.getFormattedMessage()

[PAX523]

Description

It occurs depending on the Java version and the used JVM implementation. We're migrating from Java 8 to Java 17. I cannot reproduce it with Oracle JDK 8, but with OpenJ9 JDK 8. The problem is that there are threads with an empty stacktrace which is not expected by ExtendedThreadInformation.

Configuration

Version: 2.17.2

Operating system: N/A

JDK: 17.0.3_7_openj9

Logs

java.lang.ArrayIndexOutOfBoundsException: Array index out of range: 0
	at org.apache.logging.log4j.core.message.ExtendedThreadInformation.formatState(ExtendedThreadInformation.java:141)
	at org.apache.logging.log4j.core.message.ExtendedThreadInformation.printThreadInfo(ExtendedThreadInformation.java:44)
	at org.apache.logging.log4j.message.ThreadDumpMessage.formatTo(ThreadDumpMessage.java:98)
	at org.apache.logging.log4j.message.ThreadDumpMessage.getFormattedMessage(ThreadDumpMessage.java:86)
	at de.icongmbh.dopix.logging.log4j.TestLog4jLogManager.dumpAllThreads_loggerIsEnabled_generateLogEvent(TestLog4jLogManager.java:293)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)

Reproduction

    ExtendedLogger loggerLogger = mock(ExtendedLogger.class, "loggerLogger");
    when(this.contextResolver.get()).thenReturn(this.context);
    when(this.context.getLogger(Log4jLogManager.class.getName())).thenReturn(this.loggerLogger);
    when(this.configFactory.create(any(LoggerContext.class))).thenReturn(this.config);
    this.subjectUnderTest = new Log4jLogManager(this.contextResolver, this.configFactory);
    verify(this.configFactory, atLeastOnce()).create(this.context);
    when(this.context.getLogger(LOGGER_NAME)).thenReturn(this.logger);

    when(this.loggerLogger.isEnabled(isA(Level.class), isA(Marker.class))).thenReturn(true);

    assertThat(this.subjectUnderTest.dumpAllThreads(CATEGORIES_MASK)).isTrue();

    final ArgumentCaptor<Message> message = ArgumentCaptor.forClass(Message.class);
    verify(this.loggerLogger).logMessage(eq(RESULTING_LEVEL),
                                         eq(RESULTING_MARKER),
                                         eq(Log4jLogManager.FQCN),
                                         any(StackTraceElement.class),
                                         message.capture(),
                                         ArgumentMatchers.<Throwable> isNull());
    assertThat(message.getValue().getFormattedMessage()).contains(Thread.currentThread().getName());