Metadata caching isn't compatible with prefixed cache keys

src/Persistence/Mapping/AbstractClassMetadataFactory.php

@@ -10,9 +10,6 @@
 use ReflectionClass;
 use ReflectionException;
 
-use function array_combine;
-use function array_keys;
-use function array_map;
 use function array_reverse;
 use function array_unshift;
 use function assert;
@@ -205,17 +202,10 @@ public function getMetadataFor(string $className)
                     $this->wakeupReflection($cached, $this->getReflectionService());
                 } else {
                     $loadedMetadata = $this->loadMetadata($realClassName);
-                    $classNames     = array_combine(
-                        array_map([$this, 'getCacheKey'], $loadedMetadata),
-                        $loadedMetadata
-                    );
 
-                    foreach ($this->cache->getItems(array_keys($classNames)) as $item) {
-                        if (! isset($classNames[$item->getKey()])) {
-                            continue;
-                        }
-
-                        $item->set($this->loadedMetadata[$classNames[$item->getKey()]]);
+                    foreach ($loadedMetadata as $loadedClassName) {
+                        $item = $this->cache->getItem($this->getCacheKey($loadedClassName));
+                        $item->set($this->loadedMetadata[$loadedClassName]);
                         $this->cache->saveDeferred($item);
                     }
 

tests/Persistence/Mapping/AbstractClassMetadataFactoryTest.php

@@ -9,6 +9,8 @@
 use Doctrine\Persistence\Mapping\Driver\MappingDriver;
 use Doctrine\Persistence\Mapping\MappingException;
 use Doctrine\Tests\DoctrineTestCase;
+use Psr\Cache\CacheItemInterface;
+use Psr\Cache\CacheItemPoolInterface;
 
 use function get_class;
 
@@ -83,6 +85,31 @@ public function testItGetsTheSameMetadataForBackslashedClassName(): void
 
         self::assertSame($cmf->getMetadataFor(SomeOtherEntity::class), $cmf->getMetadataFor('\\' . SomeOtherEntity::class));
     }
+
+    public function testCacheStoredWithPrefixedKeys(): void
+    {
+        $cmf = $this->getMockForAbstractClass(AbstractClassMetadataFactory::class);
+        $cmf
+            ->method('newClassMetadataInstance')
+            ->with(SomeOtherEntity::class)
+            ->willReturn(
+                $this->createStub(ClassMetadata::class)
+            );
+
+        $cache = $this->createMock(CacheItemPoolInterface::class);
+        $cmf->setCache($cache);
+
+        $cacheItem = $this->createMock(CacheItemInterface::class);
+        $cacheItem->method('getKey')->willReturn('prefix__Doctrine__Tests__Persistence__Mapping__SomeOtherEntity__CLASSMETADATA__'); //Cache item's key is prefixed
+        $cache->method('getItem')
+            ->with('Doctrine__Tests__Persistence__Mapping__SomeOtherEntity__CLASSMETADATA__') //Key which is generated from class name is not prefixed
+            ->willReturn($cacheItem);
+
+        $cacheItem->expects(self::once())->method('set');
+        $cache->expects(self::once())->method('saveDeferred');
+
+        $cmf->getMetadataFor(SomeOtherEntity::class);
+    }
 }
 
 class SomeGrandParentEntity