[LOG4J2-2067] Using PatternSelectors breaks header printing in PatternLayout

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.8.2, 2.9.0
• Component/s: Layouts, Pattern Converters
• Assignee: Unassigned
• Reporter: Paul Burrowes
• Created: 09/Oct/17 04:17
• Updated: 30/Apr/19 06:47

Description

Using a config of

<?xml version="1.0" ?>
<Configuration name="LOG4j2-1964 demo" status="ERROR">
  <Appenders>
    <Console name="consoleLog" target="SYSTEM_ERR">
      <PatternLayout pattern="%msg{nolookups}%n%throwable{none}"/>
    </Console>
    <RollingFile name="fooAppender" fileName="foo.log" filePattern="foo.log.%i">
      <PatternLayout header="log file started%n">
        <MarkerPatternSelector defaultPattern="%d{yyyy-MM-dd HH:mm:ss.SSSZ} %msg{nolookups}%n">
          <PatternMatch key="Trace" pattern="%d{yyyy-MM-dd HH:mm:ss.SSSZ} TRACER %msg{nolookups}%n"/>
        </MarkerPatternSelector>
      </PatternLayout>
      <SizeBasedTriggeringPolicy size="10MB"/>
    </RollingFile>
  </Appenders>
  <Loggers>
    <Root level="INFO">
      <AppenderRef ref="consoleLog"/>
      <AppenderRef ref="fooAppender"/>
    </Root>
  </Loggers>
</Configuration>

the header is expected to be formatted according to the pattern configured but instead the output is

2017-10-09 14:25:12.072+1300
2017-10-09 14:25:12.143+1300 using interpolation and a throwable java.lang.NullPointerException
java.lang.NullPointerException: null
        at leliel.Main.main(Main.java:51) [Log4j2-testing/:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.7.0_79]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) ~[?:1.7.0_79]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.7.0_79]
        at java.lang.reflect.Method.invoke(Method.java:606) ~[?:1.7.0_79]
        at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147) [idea_rt.jar:?]
2017-10-09 14:25:12.151+1300 throwable only

The fix appears to simply be to not provide the PatternSelector to the header and footer Serializer builders.

diff --git a/log4j-core/src/main/java/org/apache/logging/log4j/core/layout/PatternLayout.java b/log4j-core/src/main/java/org/apache/logging/log4j/core/layout/PatternLayout.java
index e4440eb9b..39042081f 100644
--- a/log4j-core/src/main/java/org/apache/logging/log4j/core/layout/PatternLayout.java
+++ b/log4j-core/src/main/java/org/apache/logging/log4j/core/layout/PatternLayout.java
@@ -108,7 +108,7 @@ public final class PatternLayout extends AbstractStringLayout {
                 newSerializerBuilder()
                         .setConfiguration(config)
                         .setReplace(replace)
-                        .setPatternSelector(patternSelector)
+                        .setPatternSelector(null)
                         .setAlwaysWriteExceptions(alwaysWriteExceptions)
                         .setDisableAnsi(disableAnsi)
                         .setNoConsoleNoAnsi(noConsoleNoAnsi)
@@ -117,7 +117,7 @@ public final class PatternLayout extends AbstractStringLayout {
                 newSerializerBuilder()
                         .setConfiguration(config)
                         .setReplace(replace)
-                        .setPatternSelector(patternSelector)
+                        .setPatternSelector(null)
                         .setAlwaysWriteExceptions(alwaysWriteExceptions)
                         .setDisableAnsi(disableAnsi)
                         .setNoConsoleNoAnsi(noConsoleNoAnsi)