Dead-letter replay writes payload format incompatible with Symfony Doctrine transport serializer

[tandev]

Ecotone version(s) affected: 1.326.1

Description
When a message is moved to dead letter, Ecotone serializes the failed Message payload to JSON using OutboundMessageConverter and defaultSerializationMediaType in ErrorChannelService (vendor/ecotone/ecotone/src/Messaging/Handler/Gateway/ErrorChannelService.php:44).

During replay, DbalDeadLetterHandler restores payload and headers, then pushes the message back into Symfony transport without converting payload format for the target transport (vendor/ecotone/dbal/src/Recoverability/DbalDeadLetterHandler.php:102).

With Symfony Doctrine transport default behavior, messages are encoded with Symfony Messenger’s PHP serializer (vendor/symfony/doctrine-messenger/Transport/DoctrineSender.php:39).

As a result, replayed payload content (JSON from Ecotone DLQ flow) is incompatible with what Doctrine transport expects (PHP-serialized envelope/body format), causing invalid data in messenger_messages and replay failures.

How to reproduce

1. Use Ecotone with DBAL dead-letter support and Symfony Messenger Doctrine transport (default serializer config).
2. Ensure defaultSerializationMediaType is JSON (default setup).
3. Dispatch a message that fails and lands in dead letter.
4. Replay the dead-letter message via Ecotone replay flow.
5. Observe that replay writes payload/body in a format that does not match Doctrine transport serializer expectations.

Context

• Alternative Solutions to solving this inside ecotone:
  • Adapt DoctrineTransport to use JSON instead of serialized php
  • Create own ErrorHandler with an more Symfony-Messenger like approach (Create another symfony messenger based dead letter queue)