Merge remote-tracking branch 'origin/master'

Author: odan

README.md

@@ -221,4 +221,9 @@ $app->group('/users', function () {
     $this->get('/login', \App\Action\UserLoginIndexAction::class);
     $this->get('/logout', \App\Action\UserLogoutAction::class);
 })->add(\Odan\Session\SessionMiddleware::class);
-```
+```
+
+## Similar packages
+
+* https://symfony.com/doc/current/components/http_foundation/sessions.html
+* https://github.com/auraphp/Aura.Session

src/SessionMiddleware.php

@@ -36,7 +36,10 @@ public function __construct(SessionInterface $session)
      */
     public function __invoke(ServerRequestInterface $request, ResponseInterface $response, $next): ResponseInterface
     {
-        $this->session->start();
+        if (!$this->session->isStarted()) {
+            $this->session->start();
+        }
+
         $response = $next($request, $response);
         $this->session->save();