Error types leak through from storage systems about scs HOT 2 CLOSED

The leaking of memcache.ErrCacheMiss was a bug with the recently contributed memcached store. The Find method should have been returning nil in the event of a cache miss (not an error) as per the store interface documentation.

It's my fault for taking the tests at face-value, instead of checking the tests to make sure they were testing the right thing.

I've fixed the behaviour in commit a01923e so it now works as documented. In the event of a cache miss, Find() will return nil, false, nil instead of nil, false, memcache.ErrCacheMiss and the session manager will create a new session as appropriate.

As for abstracting the other error types, I'm not sure if it's necessary. Generally these will be things that you would want to log and send the user a 500 Internal Server Error response for. For debugging purposes, my gut feeling is that it's better to pass through the precise, specific error so it can be logged. Having an abstraction layer, so that only scs.ErrBackendFailure (or similar) gets logged, would make identifying and debugging the underlying problem more difficult.

from scs.

Oh, sorry, I missed that section of the docs. Didn't mean to dump the responsibility of fixing my storage backend onto you.

from scs.