One more NPE fix for ContextSelector.getContext() (#1538 LOG4J2-3217)

Author: vy

log4j-core/src/main/java/org/apache/logging/log4j/core/selector/ContextSelector.java

@@ -79,7 +79,7 @@ default boolean hasContext(String fqcn, ClassLoader loader, boolean currentConte
      */
     default LoggerContext getContext(String fqcn, ClassLoader loader, Map.Entry<String, Object> entry, boolean currentContext) {
         final LoggerContext lc = getContext(fqcn, loader, currentContext);
-        if (lc != null) {
+        if (lc != null && entry != null) {
             lc.putObject(entry.getKey(), entry.getValue());
         }
         return lc;

src/changelog/.2.x.x/LOG4J2-3217_fix_NPE_in_ContextSelector.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ 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.
+  -->
+<entry xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns="http://logging.apache.org/log4j/changelog"
+       xsi:schemaLocation="http://logging.apache.org/log4j/changelog https://logging.apache.org/log4j/changelog-0.1.1.xsd"
+       type="fixed">
+  <issue id="LOG4J2-3217" link="https://issues.apache.org/jira/browse/LOG4J2-3217"/>
+  <issue id="1538" link="https://github.com/apache/logging-log4j2/pull/1538"/>
+  <author id="pbodnar" name="Petr Bodnár"/>
+  <author id="vy"/>
+  <description format="asciidoc">Fix NPE in `ContextSelector`</description>
+</entry>