Conditional drop of federated_invites table to prevent data loss.

Signed-off-by: Antoon P <antoon.prins@surf.nl>

Author: redblom

apps/cloud_federation_api/lib/Migration/Version1018Date20260202110547.php

@@ -10,15 +10,26 @@
 namespace OCA\CloudFederationAPI\Migration;
 
 use Closure;
+use OCP\AppFramework\Services\IAppConfig;
 use OCP\DB\ISchemaWrapper;
+use OCP\IDBConnection;
 use OCP\Migration\Attributes\DropTable;
 use OCP\Migration\IOutput;
 use OCP\Migration\SimpleMigrationStep;
 use Override;
 
 #[DropTable(table: 'federated_invites', columns: ['id', 'user_id', 'recipient_provider', 'recipient_user_id', 'recipient_name', 'recipient_email', 'token', 'accepted', 'created_at', 'expired_at', 'accepted_at'], description: 'Table is moved out of this app.')]
 class Version1018Date20260202110547 extends SimpleMigrationStep {
+
+	public function __construct(
+		private readonly IAppConfig $appConfig,
+		private readonly IDBConnection $db,
+	) {
+	}
+
 	/**
+	 * Drops the federated_invites table unless it contains data.
+	 * 
 	 * @param IOutput $output
 	 * @param Closure(): ISchemaWrapper $schemaClosure
 	 * @param array $options
@@ -31,8 +42,16 @@ public function changeSchema(IOutput $output, Closure $schemaClosure, array $opt
 		$table_name = 'federated_invites';
 
 		if ($schema->hasTable($table_name)) {
-			$schema->dropTable($table_name);
-			return $schema;
+			$qb = $this->db->getQueryBuilder();
+			$qb->select('*')
+				->from($table_name)
+				->setMaxResults(1);
+			$result = $qb->executeQuery();
+			$hasRows = $result->fetchOne();
+			if(!$hasRows) {
+				$schema->dropTable($table_name);
+				return $schema;
+			}
 		}
 		return null;
 	}