[Session] Fixed bug with mock file session storage

[baldurrensch]

Fixed a bug where an unstarted mock session would be emptied with a save. Here are the steps to reproduce:

1. Use the test client from Symfony\Bundle\FrameworkBundle\Test\WebTestCase::createClient(), and add something to its session. (I actually had it authenticate against a firewall).
2. Take the cookies of this first test client and add them to a second test client
3. Have the second test client request a URL that results in a 404
4. Since the 404 does not need to start the session, hence when save is called (automatically), the mock session is overwritten with an empty array. This does not happen with the other session handlers.

The added unit test in this PR shows this problem. If this PR gets accepted, will it also get merged into the 2.1.x-dev branch?

Bug fix: yes
Feature addition: no
Backwards compatibility break: no
Symfony2 tests pass: yes (The broken test seems to be unrelated to this change)
Fixes the following tickets: -
Todo: -
License of the code: MIT
Documentation PR: -

[fabpot]

ping @Drak

[ghost]

I think the logical reasoning is right because there a real unstarted session wouldn't call any save-handlers... but, what disturbs me is that the framework should not be calling the save() method if the session is not started. Maybe it doesn't matter where the stop is done, in the MockFileSessionStorage or by using a $session->isStarted() check in FrameworkBundle\Listener\TestSessionListener where it saves during testing. Can you tell me, does it also solve the problem if you just place if ($session = $event->getRequest()->getSession() && $session->isStarted()) { in the onKernelResponse method (and remove the other stop).

It's possible that a complete fix should actually include both checks, although I would suggest an exception be thrown in MockFileSessionStorage because something unexpected is happening and you should be notified about it.

What do you think? Let me know the result of the test suggested above.

(Regarding the branch question - bug fixes for the session should be branched from and applied to the 2.1 branch because it's a bug fix. Merges are applied up from the lowest branch affected. You have applied a branch to master which is for features or agreed BC breaks only).

[baldurrensch]

Ok. I tested @Drak's suggestion, and it does indeed fix the problem. Here is what I will do:

• Make the fix as suggested
• throw an exception (RuntimeException) in the MockFileSessionStorage if the session is not started and save() is called.
• Base it off of the 2.1 branch
• Close this PR and open a new one.

How does that sound?

[fabpot]

@baldurrensch Sounds good to me.

[ghost]

Yes submit a new PR.

[baldurrensch]

I opened a new PR against the correct branch: #6362