fix: handle nested auth exceptions in MySQLExceptionHandler (#1601)

Author: plastic-karma

wrapper/src/main/java/software/amazon/jdbc/exceptions/AbstractPgExceptionHandler.java

@@ -87,7 +87,7 @@ public boolean isLoginException(final Throwable throwable, @Nullable TargetDrive
       if (exception instanceof SQLException) {
         sqlState = ((SQLException) exception).getSQLState();
       } else if (targetDriverDialect != null) {
-        sqlState = targetDriverDialect.getSQLState(throwable);
+        sqlState = targetDriverDialect.getSQLState(exception);
       }
 
       if (isLoginException(sqlState)) {

wrapper/src/main/java/software/amazon/jdbc/exceptions/MySQLExceptionHandler.java

@@ -93,7 +93,7 @@ public boolean isLoginException(final Throwable throwable, @Nullable TargetDrive
       if (exception instanceof SQLException) {
         sqlState = ((SQLException) exception).getSQLState();
       } else if (targetDriverDialect != null) {
-        sqlState = targetDriverDialect.getSQLState(throwable);
+        sqlState = targetDriverDialect.getSQLState(exception);
       }
 
       if (isLoginException(sqlState)) {

wrapper/src/test/java/software/amazon/jdbc/exceptions/MySQLExceptionHandlerTest.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed 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 software.amazon.jdbc.exceptions;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import com.mysql.cj.exceptions.CJException;
+import java.sql.SQLNonTransientConnectionException;
+import org.junit.jupiter.api.Test;
+import software.amazon.jdbc.targetdriverdialect.MysqlConnectorJTargetDriverDialect;
+
+public class MySQLExceptionHandlerTest {
+
+  @Test
+  public void testIsLoginException_NestedAuthenticationException() {
+
+    MySQLExceptionHandler handler = new MySQLExceptionHandler();
+
+    // Create the nested exception structure as described in requirements
+    // Inner cause: Authentication exception with SQL state "28000"
+    CJException authException = new CJException(
+        "Access denied for user 'db_user'@'172.18.0.1' (using password: YES)"
+    );
+    authException.setSQLState("28000");
+
+    // Outer exception: Connection exception with SQL state "08001"
+    SQLNonTransientConnectionException connectionException = new SQLNonTransientConnectionException(
+        "Could not create connection to database server. Attempted reconnect 3 times. Giving up.",
+        "08001",
+        authException
+    );
+
+    assertTrue(handler.isLoginException(connectionException, new MysqlConnectorJTargetDriverDialect()),
+        "Should detect nested authentication exception with dialect");
+  }
+}