symfony
diff --git a/‎src/Symfony/Component/Cache/DependencyInjection/CachePoolPass.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Cache/DependencyInjection/CachePoolPass.php
+6-1Lines changed: 6 additions & 1 deletion b/‎src/Symfony/Component/Cache/DependencyInjection/CachePoolPass.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Cache/DependencyInjection/CachePoolPass.php
+6-1Lines changed: 6 additions & 1 deletion
diff --git a/‎src/Symfony/Component/Cache/Tests/DependencyInjection/CachePoolPassTest.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Cache/Tests/DependencyInjection/CachePoolPassTest.php
+40Lines changed: 40 additions & 0 deletions b/‎src/Symfony/Component/Cache/Tests/DependencyInjection/CachePoolPassTest.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Cache/Tests/DependencyInjection/CachePoolPassTest.php
+40Lines changed: 40 additions & 0 deletions
@@ -103,7 +103,12 @@ public function process(ContainerBuilder $container)
             if (ChainAdapter::class === $class) {
                 $adapters = [];
                 foreach ($adapter->getArgument(0) as $provider => $adapter) {
-                    $chainedPool = $adapter = new ChildDefinition($adapter);
+                    if ($adapter instanceof ChildDefinition) {
+                        $chainedPool = $adapter;
+                    } else {
+                        $chainedPool = $adapter = new ChildDefinition($adapter);
+                    }
+
                     $chainedTags = [\is_int($provider) ? [] : ['provider' => $provider]];
                     $chainedClass = '';
 
 
@@ -12,7 +12,9 @@
 namespace Symfony\Component\Cache\Tests\DependencyInjection;
 
 use PHPUnit\Framework\TestCase;
+use Symfony\Component\Cache\Adapter\ApcuAdapter;
 use Symfony\Component\Cache\Adapter\ArrayAdapter;
+use Symfony\Component\Cache\Adapter\ChainAdapter;
 use Symfony\Component\Cache\Adapter\RedisAdapter;
 use Symfony\Component\Cache\DependencyInjection\CachePoolPass;
 use Symfony\Component\DependencyInjection\ChildDefinition;
@@ -174,4 +176,42 @@ public function testThrowsExceptionWhenCachePoolTagHasUnknownAttributes()
 
         $this->cachePoolPass->process($container);
     }
+
+    public function testChainAdapterPool()
+    {
+        $container = new ContainerBuilder();
+        $container->setParameter('kernel.container_class', 'app');
+        $container->setParameter('kernel.project_dir', 'foo');
+
+        $container->register('cache.adapter.array', ArrayAdapter::class)
+            ->addTag('cache.pool');
+        $container->register('cache.adapter.apcu', ApcuAdapter::class)
+            ->setArguments([null, 0, null])
+            ->addTag('cache.pool');
+        $container->register('cache.chain', ChainAdapter::class)
+            ->addArgument(['cache.adapter.array', 'cache.adapter.apcu'])
+            ->addTag('cache.pool');
+        $container->setDefinition('cache.app', new ChildDefinition('cache.chain'))
+            ->addTag('cache.pool');
+        $container->setDefinition('doctrine.result_cache_pool', new ChildDefinition('cache.app'))
+            ->addTag('cache.pool');
+
+        $this->cachePoolPass->process($container);
+
+        $appCachePool = $container->getDefinition('cache.app');
+        $this->assertInstanceOf(ChildDefinition::class, $appCachePool);
+        $this->assertSame('cache.chain', $appCachePool->getParent());
+
+        $chainCachePool = $container->getDefinition('cache.chain');
+        $this->assertNotInstanceOf(ChildDefinition::class, $chainCachePool);
+        $this->assertCount(2, $chainCachePool->getArgument(0));
+        $this->assertInstanceOf(ChildDefinition::class, $chainCachePool->getArgument(0)[0]);
+        $this->assertSame('cache.adapter.array', $chainCachePool->getArgument(0)[0]->getParent());
+        $this->assertInstanceOf(ChildDefinition::class, $chainCachePool->getArgument(0)[1]);
+        $this->assertSame('cache.adapter.apcu', $chainCachePool->getArgument(0)[1]->getParent());
+
+        $doctrineCachePool = $container->getDefinition('doctrine.result_cache_pool');
+        $this->assertInstanceOf(ChildDefinition::class, $doctrineCachePool);
+        $this->assertSame('cache.app', $doctrineCachePool->getParent());
+    }
 }