Don't try a transaction for the migrator on MySQL

As per https://dev.mysql.com/doc/refman/8.0/en/implicit-commit.html
CREATE TABLE statements automatically commit always. The only reason
this worked in the past was that PHPs PDO connection didn't check the
actual state on commit, but only checked their internal state.
But in PHP8 this was fixed:
https://github.com/php/php-src/blob/PHP-8.0/UPGRADING#L446-L450
So now commit() fails because the internal PDO connection implicitly
commited already.

Signed-off-by: Joas Schilling <coding@schilljs.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/lib/private/DB/Migrator.php b/lib/private/DB/Migrator.php
index f62735ea6b2..e50927f620b 100644
--- a/lib/private/DB/Migrator.php
+++ b/lib/private/DB/Migrator.php
@@ -32,6 +32,7 @@
 namespace OC\DB;
 
 use Doctrine\DBAL\Exception;
+use Doctrine\DBAL\Platforms\MySQLPlatform;
 use Doctrine\DBAL\Schema\AbstractAsset;
 use Doctrine\DBAL\Schema\Comparator;
 use Doctrine\DBAL\Schema\Index;
@@ -238,14 +239,18 @@ class Migrator {
 
 		$schemaDiff = $this->getDiff($targetSchema, $connection);
 
-		$connection->beginTransaction();
+		if (!$connection->getDatabasePlatform() instanceof MySQLPlatform) {
+			$connection->beginTransaction();
+		}
 		$sqls = $schemaDiff->toSql($connection->getDatabasePlatform());
 		$step = 0;
 		foreach ($sqls as $sql) {
 			$this->emit($sql, $step++, count($sqls));
 			$connection->query($sql);
 		}
-		$connection->commit();
+		if (!$connection->getDatabasePlatform() instanceof MySQLPlatform) {
+			$connection->commit();
+		}
 	}
 
 	/**