gracefully handle missing event dispatchers

src/Symfony/Component/Messenger/Middleware/SendMessageMiddleware.php

@@ -39,7 +39,13 @@ class SendMessageMiddleware implements MiddlewareInterface
     public function __construct(SendersLocatorInterface $sendersLocator, EventDispatcherInterface $eventDispatcher = null)
     {
         $this->sendersLocator = $sendersLocator;
-        $this->eventDispatcher = LegacyEventDispatcherProxy::decorate($eventDispatcher);
+
+        if (null !== $eventDispatcher && class_exists(LegacyEventDispatcherProxy::class)) {
+            $this->eventDispatcher = LegacyEventDispatcherProxy::decorate($eventDispatcher);
+        } else {
+            $this->eventDispatcher = $eventDispatcher;
+        }
+
         $this->logger = new NullLogger();
     }
 

src/Symfony/Component/Messenger/Worker.php

@@ -52,7 +52,13 @@ class Worker implements WorkerInterface
         $this->receivers = $receivers;
         $this->bus = $bus;
         $this->retryStrategies = $retryStrategies;
-        $this->eventDispatcher = LegacyEventDispatcherProxy::decorate($eventDispatcher);
+
+        if (null !== $eventDispatcher && class_exists(LegacyEventDispatcherProxy::class)) {
+            $this->eventDispatcher = LegacyEventDispatcherProxy::decorate($eventDispatcher);
+        } else {
+            $this->eventDispatcher = $eventDispatcher;
+        }
+
         $this->logger = $logger;
     }
 

src/Symfony/Component/Security/Core/Authorization/Voter/TraceableVoter.php

@@ -31,7 +31,12 @@ class TraceableVoter implements VoterInterface
     public function __construct(VoterInterface $voter, EventDispatcherInterface $eventDispatcher)
     {
         $this->voter = $voter;
-        $this->eventDispatcher = LegacyEventDispatcherProxy::decorate($eventDispatcher);
+
+        if (class_exists(LegacyEventDispatcherProxy::class)) {
+            $this->eventDispatcher = LegacyEventDispatcherProxy::decorate($eventDispatcher);
+        } else {
+            $this->eventDispatcher = $eventDispatcher;
+        }
     }
 
     public function vote(TokenInterface $token, $subject, array $attributes)

src/Symfony/Component/Security/Guard/GuardAuthenticatorHandler.php

@@ -46,7 +46,13 @@ class GuardAuthenticatorHandler
     public function __construct(TokenStorageInterface $tokenStorage, EventDispatcherInterface $eventDispatcher = null, array $statelessProviderKeys = [])
     {
         $this->tokenStorage = $tokenStorage;
-        $this->dispatcher = LegacyEventDispatcherProxy::decorate($eventDispatcher);
+
+        if (null !== $eventDispatcher && class_exists(LegacyEventDispatcherProxy::class)) {
+            $this->dispatcher = LegacyEventDispatcherProxy::decorate($eventDispatcher);
+        } else {
+            $this->dispatcher = $eventDispatcher;
+        }
+
         $this->statelessProviderKeys = $statelessProviderKeys;
     }
 

src/Symfony/Component/Security/Http/Firewall/AbstractAuthenticationListener.php

@@ -93,7 +93,13 @@ abstract class AbstractAuthenticationListener implements ListenerInterface
             'require_previous_session' => true,
         ], $options);
         $this->logger = $logger;
-        $this->dispatcher = LegacyEventDispatcherProxy::decorate($dispatcher);
+
+        if (null !== $dispatcher && class_exists(LegacyEventDispatcherProxy::class)) {
+            $this->dispatcher = LegacyEventDispatcherProxy::decorate($dispatcher);
+        } else {
+            $this->dispatcher = $dispatcher;
+        }
+
         $this->httpUtils = $httpUtils;
     }
 

src/Symfony/Component/Security/Http/Firewall/AbstractPreAuthenticatedListener.php

@@ -52,7 +52,12 @@ abstract class AbstractPreAuthenticatedListener implements ListenerInterface
         $this->authenticationManager = $authenticationManager;
         $this->providerKey = $providerKey;
         $this->logger = $logger;
-        $this->dispatcher = LegacyEventDispatcherProxy::decorate($dispatcher);
+
+        if (null !== $dispatcher && class_exists(LegacyEventDispatcherProxy::class)) {
+            $this->dispatcher = LegacyEventDispatcherProxy::decorate($dispatcher);
+        } else {
+            $this->dispatcher = $dispatcher;
+        }
     }
 
     /**

src/Symfony/Component/Security/Http/Firewall/ContextListener.php

@@ -66,7 +66,13 @@ class ContextListener implements ListenerInterface
         $this->userProviders = $userProviders;
         $this->sessionKey = '_security_'.$contextKey;
         $this->logger = $logger;
-        $this->dispatcher = LegacyEventDispatcherProxy::decorate($dispatcher);
+
+        if (null !== $dispatcher && class_exists(LegacyEventDispatcherProxy::class)) {
+            $this->dispatcher = LegacyEventDispatcherProxy::decorate($dispatcher);
+        } else {
+            $this->dispatcher = $dispatcher;
+        }
+
         $this->trustResolver = $trustResolver ?: new AuthenticationTrustResolver(AnonymousToken::class, RememberMeToken::class);
     }
 

src/Symfony/Component/Security/Http/Firewall/RememberMeListener.php

@@ -49,7 +49,13 @@ class RememberMeListener implements ListenerInterface
         $this->rememberMeServices = $rememberMeServices;
         $this->authenticationManager = $authenticationManager;
         $this->logger = $logger;
-        $this->dispatcher = LegacyEventDispatcherProxy::decorate($dispatcher);
+
+        if (null !== $dispatcher && class_exists(LegacyEventDispatcherProxy::class)) {
+            $this->dispatcher = LegacyEventDispatcherProxy::decorate($dispatcher);
+        } else {
+            $this->dispatcher = $dispatcher;
+        }
+
         $this->catchExceptions = $catchExceptions;
         $this->sessionStrategy = null === $sessionStrategy ? new SessionAuthenticationStrategy(SessionAuthenticationStrategy::MIGRATE) : $sessionStrategy;
     }

src/Symfony/Component/Security/Http/Firewall/SimplePreAuthenticationListener.php

@@ -65,7 +65,13 @@ class SimplePreAuthenticationListener implements ListenerInterface
         $this->providerKey = $providerKey;
         $this->simpleAuthenticator = $simpleAuthenticator;
         $this->logger = $logger;
-        $this->dispatcher = LegacyEventDispatcherProxy::decorate($dispatcher);
+
+        if (null !== $dispatcher && class_exists(LegacyEventDispatcherProxy::class)) {
+            $this->dispatcher = LegacyEventDispatcherProxy::decorate($dispatcher);
+        } else {
+            $this->dispatcher = $dispatcher;
+        }
+
         $this->trustResolver = $trustResolver ?: new AuthenticationTrustResolver(AnonymousToken::class, RememberMeToken::class);
     }
 

src/Symfony/Component/Security/Http/Firewall/SwitchUserListener.php

@@ -70,7 +70,13 @@ class SwitchUserListener implements ListenerInterface
         $this->usernameParameter = $usernameParameter;
         $this->role = $role;
         $this->logger = $logger;
-        $this->dispatcher = LegacyEventDispatcherProxy::decorate($dispatcher);
+
+        if (null !== $dispatcher && class_exists(LegacyEventDispatcherProxy::class)) {
+            $this->dispatcher = LegacyEventDispatcherProxy::decorate($dispatcher);
+        } else {
+            $this->dispatcher = $dispatcher;
+        }
+
         $this->stateless = $stateless;
     }
 

src/Symfony/Component/Security/Http/Firewall/UsernamePasswordJsonAuthenticationListener.php

@@ -69,7 +69,13 @@ class UsernamePasswordJsonAuthenticationListener implements ListenerInterface
         $this->successHandler = $successHandler;
         $this->failureHandler = $failureHandler;
         $this->logger = $logger;
-        $this->eventDispatcher = LegacyEventDispatcherProxy::decorate($eventDispatcher);
+
+        if (null !== $eventDispatcher && class_exists(LegacyEventDispatcherProxy::class)) {
+            $this->eventDispatcher = LegacyEventDispatcherProxy::decorate($eventDispatcher);
+        } else {
+            $this->eventDispatcher = $eventDispatcher;
+        }
+
         $this->options = array_merge(['username_path' => 'username', 'password_path' => 'password'], $options);
         $this->propertyAccessor = $propertyAccessor ?: PropertyAccess::createPropertyAccessor();
     }

src/Symfony/Component/Workflow/Workflow.php

@@ -43,7 +43,13 @@ class Workflow implements WorkflowInterface
     {
         $this->definition = $definition;
         $this->markingStore = $markingStore ?: new MultipleStateMarkingStore();
-        $this->dispatcher = null !== $dispatcher ? LegacyEventDispatcherProxy::decorate($dispatcher) : null;
+
+        if (null !== $dispatcher && class_exists(LegacyEventDispatcherProxy::class)) {
+            $this->dispatcher = LegacyEventDispatcherProxy::decorate($dispatcher);
+        } else {
+            $this->dispatcher = $dispatcher;
+        }
+
         $this->name = $name;
     }