logger call ends with two exceptions - fix issues/876

Signed-off-by: Ceki Gulcu <[email protected]>

logback-classic/src/main/java/ch/qos/logback/classic/spi/LoggingEvent.java

@@ -436,7 +436,13 @@ public String getFormattedMessage() {
             return formattedMessage;
         }
         if (argumentArray != null) {
-            formattedMessage = MessageFormatter.arrayFormat(message, argumentArray).getMessage();
+            if(throwableProxy == null) {
+                formattedMessage = MessageFormatter.arrayFormat(message, argumentArray).getMessage();
+            } else {
+                // very rare case where the argument array ends with two exceptions
+                // See https://github.com/qos-ch/logback/issues/876
+                formattedMessage = MessageFormatter.arrayFormat(message, argumentArray, null).getMessage();
+            }
         } else {
             formattedMessage = message;
         }

logback-classic/src/test/java/ch/qos/logback/classic/issue/github876/Github876Test.java

@@ -0,0 +1,72 @@
+/*
+ * Logback: the reliable, generic, fast and flexible logging framework.
+ * Copyright (C) 1999-2024, QOS.ch. All rights reserved.
+ *
+ * This program and the accompanying materials are dual-licensed under
+ * either the terms of the Eclipse Public License v1.0 as published by
+ * the Eclipse Foundation
+ *
+ *   or (per the licensee's choosing)
+ *
+ * under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation.
+ */
+
+package ch.qos.logback.classic.issue.github876;
+
+import ch.qos.logback.classic.Logger;
+import ch.qos.logback.classic.LoggerContext;
+import ch.qos.logback.classic.spi.ILoggingEvent;
+import ch.qos.logback.classic.util.LogbackMDCAdapter;
+import ch.qos.logback.core.read.ListAppender;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class Github876Test {
+
+    LoggerContext loggerContext = new LoggerContext();
+    LogbackMDCAdapter logbackMDCAdapter = new LogbackMDCAdapter();
+    ListAppender<ILoggingEvent> listAppender = new ListAppender<ILoggingEvent>();
+    final Logger logger = loggerContext.getLogger(Github876Test.class);
+
+    @BeforeEach
+    public void setUp() {
+        loggerContext.setMDCAdapter(logbackMDCAdapter);
+
+        listAppender.setContext(loggerContext);
+        listAppender.setName("list");
+        listAppender.start();
+
+        logger.addAppender(listAppender);
+
+    }
+
+
+    @Test
+    public void traditionalTest() {
+        Exception ex = new Exception("Some message");
+        logger.error("Exception Message: {}", ex, ex);
+
+        assertEquals(1, listAppender.list.size());
+        ILoggingEvent iLoggingEvent0 = listAppender.list.get(0);
+
+        String formattedMessage0 = iLoggingEvent0.getFormattedMessage();
+        assertEquals("Exception Message: java.lang.Exception: Some message", formattedMessage0);
+    }
+
+    @Test
+    public void fluentTest() {
+        Exception ex = new Exception("Some message");
+        logger.atError().addArgument(ex)
+                        .setCause(ex).setMessage("Exception Message: {}")
+                        .log();
+
+        assertEquals(1, listAppender.list.size());
+        ILoggingEvent iLoggingEvent0 = listAppender.list.get(0);
+
+        String formattedMessage0 = iLoggingEvent0.getFormattedMessage();
+        assertEquals("Exception Message: java.lang.Exception: Some message", formattedMessage0);
+    }
+}