Possible NullPointerException in MongoDb4

Author: garydgregory

log4j-core/src/main/java/org/apache/logging/log4j/core/appender/nosql/DefaultNoSqlObject.java

@@ -42,21 +42,25 @@ public void set(final String field, final Object value) {
 
     @Override
     public void set(final String field, final NoSqlObject<Map<String, Object>> value) {
-        this.map.put(field, value.unwrap());
+        this.map.put(field, value != null ? value.unwrap() : null);
     }
 
     @Override
     public void set(final String field, final Object[] values) {
-        this.map.put(field, Arrays.asList(values));
+        this.map.put(field, values != null ? Arrays.asList(values) : null);
     }
 
     @Override
     public void set(final String field, final NoSqlObject<Map<String, Object>>[] values) {
-        final List<Map<String, Object>> list = new ArrayList<>(values.length);
-        for (final NoSqlObject<Map<String, Object>> value : values) {
-            list.add(value.unwrap());
+        if (values == null) {
+            this.map.put(field, null);
+        } else {
+            final List<Map<String, Object>> list = new ArrayList<>(values.length);
+            for (final NoSqlObject<Map<String, Object>> value : values) {
+                list.add(value.unwrap());
+            }
+            this.map.put(field, list);
         }
-        this.map.put(field, list);
     }
 
     @Override

log4j-mongodb4/src/main/java/org/apache/logging/log4j/mongodb4/MongoDb4DocumentObject.java

@@ -33,12 +33,12 @@ public MongoDb4DocumentObject() {
 
     @Override
     public void set(final String field, final NoSqlObject<Document> value) {
-        this.document.append(field, value.unwrap());
+        this.document.append(field, value != null ? value.unwrap() : null);
     }
 
     @Override
     public void set(final String field, final NoSqlObject<Document>[] values) {
-        this.document.append(field, Arrays.asList(values));
+        this.document.append(field, values != null ? Arrays.asList(values) : null);
     }
 
     @Override
@@ -48,7 +48,7 @@ public void set(final String field, final Object value) {
 
     @Override
     public void set(final String field, final Object[] values) {
-        this.document.append(field, Arrays.asList(values));
+        this.document.append(field, values != null ? Arrays.asList(values) : null);
     }
 
     @Override

src/changelog/.3.x.x/LOG4J2-3392_Possible_NullPointerException_in_MongoDb4DocumentObject_Mon.xml

@@ -0,0 +1,26 @@
+<?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="LOG4J2-3392" link="https://issues.apache.org/jira/browse/LOG4J2-3392"/>
+  <author id="ggregory"/>
+  <author name="Gary Gregory"/>
+  <description format="asciidoc">Possible NullPointerException in MongoDb4DocumentObject, MongoDbDocumentObject, DefaultNoSqlObject.</description>
+</entry>