Transaction is not rollbacked when first statement fails

src/main/java/org/mariadb/jdbc/MariaDbConnection.java

@@ -717,7 +717,7 @@ public void rollback() throws SQLException {
         if (!getAutoCommit()) {
             lock.lock();
             try {
-                if (!getAutoCommit() && protocol.inTransaction()) {
+                if (!getAutoCommit()) {
                     try (Statement st = createStatement()) {
                         st.execute("ROLLBACK");
                     }

src/test/java/org/mariadb/jdbc/TransactionTest.java

@@ -0,0 +1,141 @@
+/*
+ *
+ * MariaDB Client for Java
+ *
+ * Copyright (c) 2012-2014 Monty Program Ab.
+ * Copyright (c) 2015-2017 MariaDB Ab.
+ *
+ * This library is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 2.1 of the License, or (at your option)
+ * any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License along
+ * with this library; if not, write to Monty Program Ab info@montyprogram.com.
+ *
+ * This particular MariaDB Client for Java file is work
+ * derived from a Drizzle-JDBC. Drizzle-JDBC file which is covered by subject to
+ * the following copyright and notice provisions:
+ *
+ * Copyright (c) 2009-2011, Marcus Eriksson
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ * Redistributions of source code must retain the above copyright notice, this list
+ * of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice, this
+ * list of conditions and the following disclaimer in the documentation and/or
+ * other materials provided with the distribution.
+ *
+ * Neither the name of the driver nor the names of its contributors may not be
+ * used to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS  AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ */
+
+package org.mariadb.jdbc;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+public class TransactionTest extends BaseTest {
+
+    /**
+     * Tables initialisation.
+     *
+     * @throws SQLException
+     *             exception
+     */
+    @BeforeClass()
+    public static void initClass() throws SQLException {
+        Statement stmt = sharedConnection.createStatement();
+        stmt.execute("drop table if exists tx_fore_key");
+        stmt.execute("drop table if exists tx_prim_key");
+        createTable("tx_prim_key", "id int not null primary key", "engine=innodb");
+        createTable("tx_fore_key",
+                "id int not null primary key, id_ref int not null, "
+                        + "foreign key (id_ref) references tx_prim_key(id) on delete restrict on update restrict",
+                "engine=innodb");
+    }
+
+    /**
+     * Clean up created tables.
+     * 
+     * @throws SQLException
+     *             exception                
+     */
+    @AfterClass
+    public static void afterClass() throws SQLException {
+        Statement stmt = sharedConnection.createStatement();
+        stmt.execute("drop table if exists tx_fore_key");
+        stmt.execute("drop table if exists tx_prim_key");
+    }
+
+    /*
+     * Test with different APIs that generated keys work. Also test that any name in
+     * generatedKeys.getXXX(String name) can be passed and is equivalent to
+     * generatedKeys.getXXX(1). This might not be 100% compliant, but is a simple
+     * and effective solution for MySQL that does not does not support more than a
+     * single autogenerated value.
+     */
+    @Test
+    public void testProperRollback() throws Exception {
+        // 1. setup test data
+        try (Statement st = sharedConnection.createStatement()) {
+            st.executeUpdate("insert into tx_prim_key(id) values(32)");
+            st.executeUpdate("insert into tx_fore_key(id, id_ref) values(42, 32)");
+        }
+
+        // 2. try to delete entry in Primary table in a transaction - wich will fail due
+        // foreign key.
+        sharedConnection.setAutoCommit(false);
+        try (Statement st = sharedConnection.createStatement()) {
+            st.executeUpdate("delete from tx_prim_key where id = 32");
+            sharedConnection.commit();
+            fail("Expected SQLException");
+        } catch (SQLException e) {
+            // This exception is expected
+            assertTrue(e.getMessage().contains("a foreign key constraint fails"));
+            // expected exception: Cannot delete or update a parent row: a foreign key
+            // constraint fails
+            sharedConnection.rollback(); // <-- will not properly roll back the transaction
+            // st.execute("ROLLBACK"); <-- will fix the problem
+        }
+
+        // 3. now try to delete it in a second connection. Note that there is an open
+        // transaction
+        // from attempt #2 which locks the table. Put breakpoint here and execute
+        // "SELECT * FROM information_schema.INNODB_TRX" to see the transaction
+        try (Connection conn2 = openNewConnection(connUri); Statement st = conn2.createStatement()) {
+            st.setQueryTimeout(3);
+            st.executeUpdate("delete from tx_fore_key where id = 42");
+            st.executeUpdate("delete from tx_prim_key where id = 32");
+        }
+    }
+
+}