Using the new PdoSessionHandler (instead of the depecated legacy code) we do get errors saving session data since there are \0 bytes in the data.

After some digging I realized that the difference is that the legacy handler does base64 encode/decode and the new handler doesn't.
I suppose this does work with the databases explicitely supported, but it does break things for others.

Was this a concious decision to remove the encode/decode or could this be added again? I'd be happy to create a PR...\

EDIT: I should mention that I am using Sybase with dblib.