(logging-log4j2) branch 2.x updated: fix: treat null parameters as empty in `CsvParameterLayout` (#4245)

[vy]

This is an automated email from the ASF dual-hosted git repository.

vy pushed a commit to branch 2.x
in repository https://gitbox.apache.org/repos/asf/logging-log4j2.git


The following commit(s) were added to refs/heads/2.x by this push:
     new abcb38f9cc fix: treat null parameters as empty in `CsvParameterLayout` 
(#4245)
abcb38f9cc is described below

commit abcb38f9ccbe52542b660f939cef4066b6012c66
Author: dev_Hakaze <af.naw...@gmail.com>
AuthorDate: Thu Aug 27 19:03:27 2026 +0700

    fix: treat null parameters as empty in `CsvParameterLayout` (#4245)
    
    Co-authored-by: Volkan Yazıcı <vol...@yazi.ci>
---
 .../log4j/core/layout/CsvParameterLayoutTest.java        | 16 ++++++++++++++++
 .../logging/log4j/core/layout/CsvParameterLayout.java    |  3 ++-
 .../4243_fix_CsvParameterLayout_null_parameters.xml      | 13 +++++++++++++
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git 
a/log4j-core-test/src/test/java/org/apache/logging/log4j/core/layout/CsvParameterLayoutTest.java
 
b/log4j-core-test/src/test/java/org/apache/logging/log4j/core/layout/CsvParameterLayoutTest.java
index 50bff2beac..466e5ba4b1 100644
--- 
a/log4j-core-test/src/test/java/org/apache/logging/log4j/core/layout/CsvParameterLayoutTest.java
+++ 
b/log4j-core-test/src/test/java/org/apache/logging/log4j/core/layout/CsvParameterLayoutTest.java
@@ -29,11 +29,14 @@ import org.apache.commons.csv.CSVFormat;
 import org.apache.logging.log4j.Level;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.core.Appender;
+import org.apache.logging.log4j.core.LogEvent;
 import org.apache.logging.log4j.core.Logger;
+import org.apache.logging.log4j.core.impl.Log4jLogEvent;
 import org.apache.logging.log4j.core.test.appender.ListAppender;
 import org.apache.logging.log4j.core.test.categories.Layouts;
 import org.apache.logging.log4j.core.test.junit.LoggerContextRule;
 import org.apache.logging.log4j.message.ObjectArrayMessage;
+import org.apache.logging.log4j.message.SimpleMessage;
 import org.apache.logging.log4j.test.junit.ThreadContextRule;
 import org.junit.Assert;
 import org.junit.Rule;
@@ -170,6 +173,19 @@ public class CsvParameterLayoutTest {
         testLayoutNormalApi(root, 
CsvParameterLayout.createLayout(CSVFormat.TDF), true);
     }
 
+    @Test
+    public void testNullParametersProduceEmptyRecord() {
+        // SimpleMessage#getParameters() returns null; must not NPE (GH-4243)
+        final AbstractCsvLayout layout = 
CsvParameterLayout.createDefaultLayout();
+        final LogEvent event = Log4jLogEvent.newBuilder()
+                .setLoggerName("test")
+                .setLevel(Level.INFO)
+                .setMessage(new SimpleMessage("plain text without parameters"))
+                .build();
+        final String result = layout.toSerializable(event);
+        Assert.assertEquals(layout.getFormat().getRecordSeparator(), result);
+    }
+
     @Test
     public void testLogJsonArgument() throws InterruptedException {
         final ListAppender appender = init.getAppender("List");
diff --git 
a/log4j-core/src/main/java/org/apache/logging/log4j/core/layout/CsvParameterLayout.java
 
b/log4j-core/src/main/java/org/apache/logging/log4j/core/layout/CsvParameterLayout.java
index c680ab792d..c738c80137 100644
--- 
a/log4j-core/src/main/java/org/apache/logging/log4j/core/layout/CsvParameterLayout.java
+++ 
b/log4j-core/src/main/java/org/apache/logging/log4j/core/layout/CsvParameterLayout.java
@@ -30,6 +30,7 @@ import 
org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
 import org.apache.logging.log4j.core.config.plugins.PluginFactory;
 import org.apache.logging.log4j.message.Message;
 import org.apache.logging.log4j.status.StatusLogger;
+import org.apache.logging.log4j.util.Constants;
 
 /**
  * A Comma-Separated Value (CSV) layout to log event parameters.
@@ -95,7 +96,7 @@ public class CsvParameterLayout extends AbstractCsvLayout {
         final Object[] parameters = message.getParameters();
         final StringBuilder buffer = getStringBuilder();
         try {
-            getFormat().printRecord(buffer, parameters);
+            getFormat().printRecord(buffer, parameters == null ? 
Constants.EMPTY_OBJECT_ARRAY : parameters);
             return buffer.toString();
         } catch (final IOException e) {
             StatusLogger.getLogger().error(message, e);
diff --git 
a/src/changelog/.2.x.x/4243_fix_CsvParameterLayout_null_parameters.xml 
b/src/changelog/.2.x.x/4243_fix_CsvParameterLayout_null_parameters.xml
new file mode 100644
index 0000000000..2849ce03f2
--- /dev/null
+++ b/src/changelog/.2.x.x/4243_fix_CsvParameterLayout_null_parameters.xml
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<entry xmlns="https://logging.apache.org/xml/ns";
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
+       xsi:schemaLocation="
+           https://logging.apache.org/xml/ns
+           https://logging.apache.org/xml/ns/log4j-changelog-0.xsd";
+       type="fixed">
+  <issue id="4243" 
link="https://github.com/apache/logging-log4j2/issues/4243"/>
+  <issue id="4245" link="https://github.com/apache/logging-log4j2/pull/4245"/>
+  <description format="asciidoc">
+    Fix `NullPointerException` in `CsvParameterLayout` when a log event has no 
parameters (for example `SimpleMessage`).
+  </description>
+</entry>