Fix ArrayIndexOutOfBoundsException in StatusData#getFormattedStatus (#3563)

Co-authored-by: Brian Laub <blaub@palantir.com>

Author: bjlaub

log4j-api-test/src/test/java/org/apache/logging/log4j/status/StatusDataTest.java

@@ -0,0 +1,52 @@
+/*
+ * 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.
+ */
+package org.apache.logging.log4j.status;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.message.Message;
+import org.apache.logging.log4j.util.Constants;
+import org.junit.jupiter.api.Test;
+
+public class StatusDataTest {
+    @Test
+    void test_getFormattedData_does_not_throw() {
+        // ensure that getFormattedData() does not throw an ArrayIndexOutOfBoundsException when given
+        // a message with a 0-length (non-null) parameters array
+
+        Message message = new Message() {
+            @Override
+            public String getFormattedMessage() {
+                return "formatted";
+            }
+
+            @Override
+            public Object[] getParameters() {
+                return Constants.EMPTY_OBJECT_ARRAY;
+            }
+
+            @Override
+            public Throwable getThrowable() {
+                return null;
+            }
+        };
+
+        StatusData statusData = new StatusData(null, Level.ERROR, message, null, null);
+        assertThat(statusData.getFormattedStatus()).contains("formatted");
+    }
+}

log4j-api/src/main/java/org/apache/logging/log4j/status/StatusData.java

@@ -179,7 +179,10 @@ public String getFormattedStatus() {
         sb.append(message.getFormattedMessage());
         final Object[] parameters = message.getParameters();
         Throwable effectiveThrowable;
-        if (throwable == null && parameters != null && parameters[parameters.length - 1] instanceof Throwable) {
+        if (throwable == null
+                && parameters != null
+                && parameters.length > 0
+                && parameters[parameters.length - 1] instanceof Throwable) {
             effectiveThrowable = (Throwable) parameters[parameters.length - 1];
         } else {
             effectiveThrowable = throwable;

src/changelog/.2.x.x/3562_StatusData_ArrayIndexOutOfBounds.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<entry xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns="https://logging.apache.org/xml/ns"
+       xsi:schemaLocation="https://logging.apache.org/xml/ns https://logging.apache.org/xml/ns/log4j-changelog-0.xsd"
+       type="fixed">
+  <issue id="3562" link="https://github.com/apache/logging-log4j2/issues/3562"/>
+  <description format="asciidoc">
+    Fix `ArrayIndexOutOfBoundsException` on `StatusData#getFormattedStatus`.
+  </description>
+</entry>