Stop throwing exceptions on commit in PHP8+pdo_mysql combo

MySQL commits implicitly after every DDL query, but since PHP 8, mysql_pdo started to throw exception when attempting to explicitly commit after it implicitly committed. This causes to interrupt the migration process even though all queries completed successfully.

Alternative would be to disable transaction for PHP8+pdo_mysql, but that would affect all queries, not only DDL ones like intended, hence going with guard check before each explicit commit.

Hopefully this will be fixed directly in DBAL in future, but so far this doesn't look very likely...

lib/Doctrine/Migrations/Event/Listeners/AutoCommitListener.php

@@ -7,6 +7,7 @@
 use Doctrine\Common\EventSubscriber;
 use Doctrine\Migrations\Event\MigrationsEventArgs;
 use Doctrine\Migrations\Events;
+use Doctrine\Migrations\Tools\Console\TransactionHelper;
 
 /**
  * Listens for `onMigrationsMigrated` and, if the connection has autocommit
@@ -24,7 +25,7 @@ public function onMigrationsMigrated(MigrationsEventArgs $args): void
             return;
         }
 
-        $conn->commit();
+        TransactionHelper::commitIfInTransaction($conn);
     }
 
     /** {@inheritdoc} */

lib/Doctrine/Migrations/Migrator.php

@@ -9,6 +9,7 @@
 use Doctrine\Migrations\Exception\NoMigrationsToExecute;
 use Doctrine\Migrations\Exception\UnknownMigrationVersion;
 use Doctrine\Migrations\Tools\BytesFormatter;
+use Doctrine\Migrations\Tools\Console\TransactionHelper;
 use Doctrine\Migrations\Version\Direction;
 use Doctrine\Migrations\Version\Version;
 use Symfony\Component\Stopwatch\StopwatchEvent;
@@ -202,7 +203,7 @@ private function executeMigration(
         }
 
         if ($allOrNothing) {
-            $connection->commit();
+            TransactionHelper::commitIfInTransaction($connection);
         }
 
         return $sql;

lib/Doctrine/Migrations/Tools/Console/TransactionHelper.php

@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Migrations\Tools\Console;
+
+use Doctrine\DBAL\Connection;
+use PDO;
+
+/**
+ * @internal
+ */
+final class TransactionHelper
+{
+    public static function commitIfInTransaction(Connection $connection): void
+    {
+        $wrappedConnection = $connection->getWrappedConnection();
+
+        // Attempt to commit while no transaction is running results in exception since PHP 8 + pdo_mysql combination
+        if ($wrappedConnection instanceof PDO && ! $wrappedConnection->inTransaction()) {
+            return;
+        }
+
+        $connection->commit();
+    }
+}

lib/Doctrine/Migrations/Tracking/TableUpdater.php

@@ -9,6 +9,7 @@
 use Doctrine\DBAL\Schema\AbstractSchemaManager;
 use Doctrine\DBAL\Schema\Schema;
 use Doctrine\DBAL\Schema\Table;
+use Doctrine\Migrations\Tools\Console\TransactionHelper;
 use Throwable;
 
 use function in_array;
@@ -66,7 +67,7 @@ public function updateMigrationTable(): void
             throw $e;
         }
 
-        $this->connection->commit();
+        TransactionHelper::commitIfInTransaction($this->connection);
     }
 
     /**

lib/Doctrine/Migrations/Version/Executor.php

@@ -16,6 +16,7 @@
 use Doctrine\Migrations\Provider\SchemaDiffProviderInterface;
 use Doctrine\Migrations\Stopwatch;
 use Doctrine\Migrations\Tools\BytesFormatter;
+use Doctrine\Migrations\Tools\Console\TransactionHelper;
 use Throwable;
 
 use function count;
@@ -257,8 +258,7 @@ private function executeMigration(
         }
 
         if ($migration->isTransactional()) {
-            //commit only if running in transactional mode
-            $this->connection->commit();
+            TransactionHelper::commitIfInTransaction($this->connection);
         }
 
         $version->setState(State::NONE);