This is an automated email from the ASF dual-hosted git repository. ramanathan1504 pushed a commit to branch fix/plugin-element-visitor-array-npe in repository https://gitbox.apache.org/repos/asf/logging-log4j2.git
commit 28192c89a5a6dd47dbec65b1cb00f4ff2e18e4e8 Author: Ramanathan <[email protected]> AuthorDate: Wed Aug 12 14:51:18 2026 +0530 Fix NPE in PluginElementVisitor when handling unresolved child elements --- .../properties/PropertiesConfigurationTest.java | 26 ++++++++++++++++++++++ .../resources/log4j2-unresolved-layout.properties | 26 ++++++++++++++++++++++ .../plugins/visitors/PluginElementVisitor.java | 4 ++++ .../4248_fix_plugin_element_visitor_array_npe.xml | 13 +++++++++++ 4 files changed, 69 insertions(+) diff --git a/log4j-core-test/src/test/java/org/apache/logging/log4j/core/config/properties/PropertiesConfigurationTest.java b/log4j-core-test/src/test/java/org/apache/logging/log4j/core/config/properties/PropertiesConfigurationTest.java index e2b76e7072..3b301f15cf 100644 --- a/log4j-core-test/src/test/java/org/apache/logging/log4j/core/config/properties/PropertiesConfigurationTest.java +++ b/log4j-core-test/src/test/java/org/apache/logging/log4j/core/config/properties/PropertiesConfigurationTest.java @@ -21,6 +21,7 @@ import static org.hamcrest.Matchers.instanceOf; import static org.junit.jupiter.api.Assertions.assertEquals; import static org.junit.jupiter.api.Assertions.assertInstanceOf; import static org.junit.jupiter.api.Assertions.assertNotNull; +import static org.junit.jupiter.api.Assertions.assertTrue; import java.util.List; import java.util.Map; @@ -32,6 +33,7 @@ import org.apache.logging.log4j.core.Filter; import org.apache.logging.log4j.core.LifeCycle; import org.apache.logging.log4j.core.LogEvent; import org.apache.logging.log4j.core.LoggerContext; +import org.apache.logging.log4j.core.appender.ConsoleAppender; import org.apache.logging.log4j.core.config.Configuration; import org.apache.logging.log4j.core.config.LoggerConfig; import org.apache.logging.log4j.core.config.Property; @@ -39,6 +41,9 @@ import org.apache.logging.log4j.core.filter.ThresholdFilter; import org.apache.logging.log4j.core.test.appender.ListAppender; import org.apache.logging.log4j.core.test.junit.LoggerContextSource; import org.apache.logging.log4j.core.test.junit.Named; +import org.apache.logging.log4j.status.StatusData; +import org.apache.logging.log4j.test.ListStatusListener; +import org.apache.logging.log4j.test.junit.UsingStatusListener; import org.junit.jupiter.api.Test; import org.junitpioneer.jupiter.SetSystemProperty; @@ -168,4 +173,25 @@ class PropertiesConfigurationTest { final List<LogEvent> thirdEvents = third.getEvents(); assertEquals(1, thirdEvents.size()); } + + @Test + @UsingStatusListener + @LoggerContextSource("log4j2-unresolved-layout.properties") + void testUnresolvedLayoutDoesNotFailConfiguration(final Configuration config, final ListStatusListener listener) { + assertEquals(LifeCycle.State.STARTED, config.getState()); + assertTrue( + listener.findStatusData(Level.ERROR).anyMatch(data -> data.getMessage() + .getFormattedMessage() + .contains("Unable to locate plugin for ThisLayoutDoesNotExist")), + "Unresolved layout was not reported"); + assertTrue( + listener.getStatusData() + .map(StatusData::getThrowable) + .noneMatch(NullPointerException.class::isInstance), + "Unresolved layout caused a NullPointerException"); + final Appender appender = config.getAppender("StdOut"); + assertNotNull(appender, "Appender was not created"); + assertInstanceOf(ConsoleAppender.class, appender); + assertNotNull(appender.getLayout(), "No default layout"); + } } diff --git a/log4j-core-test/src/test/resources/log4j2-unresolved-layout.properties b/log4j-core-test/src/test/resources/log4j2-unresolved-layout.properties new file mode 100644 index 0000000000..dc2f9b31a0 --- /dev/null +++ b/log4j-core-test/src/test/resources/log4j2-unresolved-layout.properties @@ -0,0 +1,26 @@ +# +# Licensed to the Apache Software Foundation (ASF) under one or more +# contributor license agreements. See the NOTICE file distributed with +# this work for additional information regarding copyright ownership. +# The ASF licenses this file to you under the Apache License, Version 2.0 +# (the "License"); you may not use this file except in compliance with +# the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# + +status = OFF + +appender.Stdout.type = Console +appender.Stdout.name = StdOut +appender.Stdout.target = SYSTEM_OUT +appender.Stdout.layout.type = ThisLayoutDoesNotExist + +rootLogger.appenderRef.console.ref = StdOut +rootLogger.level = ERROR diff --git a/log4j-core/src/main/java/org/apache/logging/log4j/core/config/plugins/visitors/PluginElementVisitor.java b/log4j-core/src/main/java/org/apache/logging/log4j/core/config/plugins/visitors/PluginElementVisitor.java index ef32b3737c..198f69d04c 100644 --- a/log4j-core/src/main/java/org/apache/logging/log4j/core/config/plugins/visitors/PluginElementVisitor.java +++ b/log4j-core/src/main/java/org/apache/logging/log4j/core/config/plugins/visitors/PluginElementVisitor.java @@ -47,6 +47,10 @@ public class PluginElementVisitor extends AbstractPluginVisitor<PluginElement> { boolean first = true; for (final Node child : node.getChildren()) { final PluginType<?> childType = child.getType(); + if (childType == null) { + LOGGER.debug("Ignoring unresolved element {} in {}.", child.getName(), node.getName()); + continue; + } if (name.equalsIgnoreCase(childType.getElementName()) || this.conversionType.isAssignableFrom(childType.getPluginClass())) { if (!first) { diff --git a/src/changelog/.2.x.x/4248_fix_plugin_element_visitor_array_npe.xml b/src/changelog/.2.x.x/4248_fix_plugin_element_visitor_array_npe.xml new file mode 100644 index 0000000000..18be792b42 --- /dev/null +++ b/src/changelog/.2.x.x/4248_fix_plugin_element_visitor_array_npe.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="4248" link="https://github.com/apache/logging-log4j2/issues/4248"/> + <issue id="4250" link="https://github.com/apache/logging-log4j2/pull/4250"/> + <description format="asciidoc"> + Fix `NPE` while injecting array elements of a plugin that has an unresolved child element. + </description> +</entry> \ No newline at end of file
