fix(symfony): detach objects to prevent loop when using Doctrine middleware and Mercure (api-platform#6936) (api-platform#6965)

Author: LaurentHuzard

src/Symfony/Doctrine/EventListener/PublishMercureUpdatesListener.php

@@ -131,16 +131,29 @@ public function onFlush(EventArgs $eventArgs): void
     public function postFlush(): void
     {
         try {
-            foreach ($this->createdObjects as $object) {
-                $this->publishUpdate($object, $this->createdObjects[$object], 'create');
+            $creatingObjects = clone $this->createdObjects;
+            foreach ($creatingObjects as $object) {
+                if ($this->createdObjects->contains($object)) {
+                    $this->createdObjects->detach($object);
+                }
+                $this->publishUpdate($object, $creatingObjects[$object], 'create');
             }
 
-            foreach ($this->updatedObjects as $object) {
-                $this->publishUpdate($object, $this->updatedObjects[$object], 'update');
+            $updatingObjects = clone $this->updatedObjects;
+            foreach ($updatingObjects as $object) {
+                if ($this->updatedObjects->contains($object)) {
+                    $this->updatedObjects->detach($object);
+                }
+                $this->publishUpdate($object, $updatingObjects[$object], 'update');
             }
 
-            foreach ($this->deletedObjects as $object) {
-                $this->publishUpdate($object, $this->deletedObjects[$object], 'delete');
+            $deletingObjects = clone $this->deletedObjects;
+            foreach ($deletingObjects as $object) {
+                $options = $this->deletedObjects[$object];
+                if ($this->deletedObjects->contains($object)) {
+                    $this->deletedObjects->detach($object);
+                }
+                $this->publishUpdate($object, $deletingObjects[$object], 'delete');
             }
         } finally {
             $this->reset();
@@ -237,7 +250,6 @@ private function publishUpdate(object $object, array $options, string $type): vo
         }
 
         $updates = array_merge([$this->buildUpdate($iri, $data, $options)], $this->getGraphQlSubscriptionUpdates($object, $options, $type));
-
         foreach ($updates as $update) {
             if ($options['enable_async_update'] && $this->messageBus) {
                 $this->dispatch($update);