Chain user provider doesn't search in all user providers

[Abhoryo]

I commit these changes because Chain user provider doesn't search in all user providers.

Example with the Acme/DemoBundle:

// security.yml
...
    providers:
        chain_provider:
            providers: [in_memory, in_memory_extend]
        in_memory_extend:
            users:
                admin2: { password: adminpass2, roles: [ 'ROLE_ADMIN' ] }
        in_memory:
            users:
                user:  { password: userpass, roles: [ 'ROLE_USER' ] }
...
    firewalls:
...
        secured_area:
            pattern:    ^/demo/secured/
            provider: chain_provider OR in_memory_extend
...

We can see these logs :

security.INFO: User "admin2" has been authenticated successfully [] []
security.DEBUG: Write SecurityContext in the session [] []
security.DEBUG: Read SecurityContext from the session [] []
security.DEBUG: Reloading user from user provider. [] []
security.WARNING: Username "admin2" could not be found. [] []

The new code search in others user providers when a user is not found in the first user provider and throws the right exception.

[lsmith77]

I wonder if it should be a provider option to continue on a failed user lookup. I can see cases where you really dont want to iterate over all providers and others where you do.

[Abhoryo]

If someone need a provider like you describe, he can create one.
Here we talk about a chain user provider.

Doc : using-multiple-user-providers

We can read in the doc: "The chain_provider will, in turn, try to load the user from both the in_memory and user_db providers."
But its not the case right now.