classes/Http/SessionMiddleware.php
public function handle(Request $request, $type = HttpKernelInterface::MASTER_REQUEST, $catch = true)
	{
		// always set the session onto the request object.
		$request->setSession($this->session);

		// we only need to manage the session for the master request.
		// subrequests will have the session available anyways, but we will
		// be closing and setting the cookie for the master request only.
		if ($type !== HttpKernelInterface::MASTER_REQUEST) {
			return $this->kernel->handle($request, $type, $catch);
		}

		// the session may have been manually started before the middleware is
		// invoked - in this case, we cross our fingers and hope the session has
		// properly initialised itself
		if (!$this->session->isStarted()) {
			$this->initSession($request);
		}

		$response = $this->kernel->handle($request, $type, $catch);

		// if the session has started, save it and attach the session cookie. if
		// the session has not started, there is nothing to save and there is no
		// point in attaching a cookie to persist it.
		if ($this->session->isStarted()) {
			$this->closeSession($request, $response);
		}

		return $response;
	}
public function handle(Request $request, $type = HttpKernelInterface::MASTER_REQUEST, $catch = true)
	{
		// always set the session onto the request object.
		$request->setSession($this->session);

		// we only need to manage the session for the master request.
		// subrequests will have the session available anyways, but we will
		// be closing and setting the cookie for the master request only.
		if ($type !== HttpKernelInterface::MASTER_REQUEST) {
			return $this->kernel->handle($request, $type, $catch);
		}

		// the session may have been manually started before the middleware is
		// invoked - in this case, we cross our fingers and hope the session has
		// properly initialised itself
		if (!$this->session->isStarted()) {
			$this->initSession($request);
		}

		$response = $this->kernel->handle($request, $type, $catch);

		// if the session has started, save it and attach the session cookie. if
		// the session has not started, there is nothing to save and there is no
		// point in attaching a cookie to persist it.
		if ($this->session->isStarted()) {
			$this->closeSession($request, $response);
		}

		return $response;
	}
{@inheritdoc}