Logger log doubles about swiftmailer-bundle

[hanneskaeufler]

I get some weird behaviour after updating to symfony 2.4 in which a test of mine fails because the SwiftMailer Message Collector also registers two messages sent were only one was actually sent.

[TrickyC94]

I've just noticed this behaviour too (v2.6.7). I tried to reproduce what happened under the hood.

1. I call $mailer->send($message)
2. The mailer calls $this->_transport->send($message) where _transport is a SpoolTransport instance
3. The SpoolTransport dispatches the "beforeSendPerformed" event
4. Logger is subscribed to that event and log once
5. Symfony dispatches the "kernel.terminate" event
6. The EmailSenderListner is subscribed to that event and it calls $spool->flushQueue($realTransport) in my case $spool is MemorySpool and the real transport now is the NullTransport
7. The flushQueue method calls the send method on NullTransport
8. NullTransport dispatches the "beforeSendPerformed"
9. Logger is subscribed to that event and logs twice

@fabpot I think that this behaviour needs to be reviewed somehow, or, if this is the expected behaviour, to update the docs

[fabpot]

Closing old issues.