Revert "[TASK] Avoid slow array functions in loops"

This reverts commit e531ddce.

Reason for revert: immature merge

Change-Id: Ia31248587537a502ffdfc84761bacd7095999642
Resolves: #89276
Reverts: #89056
Releases: master
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/61815

Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>

typo3/sysext/backend/Classes/Clipboard/Clipboard.php

@@ -372,7 +372,7 @@ class Clipboard
      */
     public function getContentFromTab($pad)
     {
-        $lines = [[]];
+        $lines = [];
         if (is_array($this->clipData[$pad]['el'] ?? false)) {
             foreach ($this->clipData[$pad]['el'] as $k => $v) {
                 if ($v) {
@@ -434,7 +434,7 @@ class Clipboard
 
                             $localizationData = $this->getLocalizations($table, $rec);
                             if (!empty($localizationData)) {
-                                $lines[] = $localizationData;
+                                $lines = array_merge($lines, $localizationData);
                             }
                         } else {
                             unset($this->clipData[$pad]['el'][$k]);
@@ -445,7 +445,7 @@ class Clipboard
             }
         }
         $this->endClipboard();
-        return array_merge(...$lines);
+        return $lines;
     }
 
     /**

typo3/sysext/backend/Classes/Controller/ContentElement/NewContentElementController.php

@@ -360,7 +360,7 @@ class NewContentElementController
      */
     protected function getWizards(): array
     {
-        $wizardItems = [[]];
+        $wizardItems = [];
         if (is_array($this->config)) {
             $wizards = $this->config['wizardItems.'] ?? [];
             $appendWizards = $this->getAppendWizards($wizards['elements.'] ?? []);
@@ -393,14 +393,13 @@ class NewContentElementController
                         }
                     }
                     if (!empty($groupItems)) {
-                        $wizardItems[] = [$groupKey => $this->getWizardGroupHeader($wizardGroup)];
-                        $wizardItems[] = $groupItems;
+                        $wizardItems[$groupKey] = $this->getWizardGroupHeader($wizardGroup);
+                        $wizardItems = array_merge($wizardItems, $groupItems);
                     }
                 }
             }
         }
         // Remove elements where preset values are not allowed:
-        $wizardItems = array_merge(...$wizardItems);
         $this->removeInvalidWizardItems($wizardItems);
         return $wizardItems;
     }

typo3/sysext/backend/Classes/Controller/Page/TreeController.php

@@ -193,12 +193,12 @@ class TreeController
         } else {
             $entryPoints = $this->getAllEntryPointPageTrees();
         }
-        $items = [[]];
+        $items = [];
         foreach ($entryPoints as $page) {
-            $items[] = $this->pagesToFlatArray($page, (int)$page['uid']);
+            $items = array_merge($items, $this->pagesToFlatArray($page, (int)$page['uid']));
         }
 
-        return new JsonResponse(array_merge(...$items));
+        return new JsonResponse($items);
     }
 
     /**
@@ -280,8 +280,8 @@ class TreeController
             $prefix = htmlspecialchars('[' . $pageId . '] ');
         }
 
-        $items = [[]];
-        $items[] = [[
+        $items = [];
+        $items[] = [
             // Used to track if the tree item is collapsed or not
             'stateIdentifier' => $identifier,
             'identifier' => $pageId,
@@ -305,13 +305,13 @@ class TreeController
             'isMountPoint' => $depth === 0,
             'mountPoint' => $entryPoint,
             'workspaceId' => !empty($page['t3ver_oid']) ? $page['t3ver_oid'] : $pageId,
-        ]];
+        ];
         if (!$stopPageTree) {
             foreach ($page['_children'] as $child) {
-                $items[] = $this->pagesToFlatArray($child, $entryPoint, $depth + 1, ['backgroundColor' => $backgroundColor]);
+                $items = array_merge($items, $this->pagesToFlatArray($child, $entryPoint, $depth + 1, ['backgroundColor' => $backgroundColor]));
             }
         }
-        return array_merge(...$items);
+        return $items;
     }
 
     /**

typo3/sysext/backend/Classes/Form/FormDataProvider/AbstractItemProvider.php

@@ -752,7 +752,7 @@ abstract class AbstractItemProvider
     protected function getExcludeFields()
     {
         $languageService = $this->getLanguageService();
-        $finalExcludeArray = [[]];
+        $finalExcludeArray = [];
 
         // Fetch translations for table names
         $tableToTranslation = [];
@@ -836,11 +836,11 @@ abstract class AbstractItemProvider
                     }
                     return 0;
                 });
-                $finalExcludeArray[] = $excludeArrayTable;
+                $finalExcludeArray = array_merge($finalExcludeArray, $excludeArrayTable);
             }
         }
 
-        return array_merge(...$finalExcludeArray);
+        return $finalExcludeArray;
     }
 
     /**

typo3/sysext/backend/Classes/Form/FormDataProvider/TcaTypesShowitem.php

@@ -183,7 +183,7 @@ class TcaTypesShowitem implements FormDataProviderInterface
      */
     protected function removeFieldsByBitmaskExcludeBits(array $result, $bitmaskValue, $recordTypeValue)
     {
-        $removeListArray = [[]];
+        $removeListArray = [];
         $bitmaskValue = MathUtility::forceIntegerInRange($bitmaskValue, 0);
         $excludeListBitsArray = $this->processedTca['types'][$recordTypeValue]['bitmask_excludelist_bits'];
         foreach ($excludeListBitsArray as $bitKey => $excludeList) {
@@ -193,10 +193,9 @@ class TcaTypesShowitem implements FormDataProviderInterface
             if (!$isNegative && ($bitmaskValue & pow(2, $bit))
                 || $isNegative && !($bitmaskValue & pow(2, $bit))
             ) {
-                $removeListArray[] = GeneralUtility::trimExplode(',', $excludeList, true);
+                $removeListArray = array_merge($removeListArray, GeneralUtility::trimExplode(',', $excludeList, true));
             }
         }
-        $removeListArray = array_merge(...$removeListArray);
         $result = $this->removeFields($result, $removeListArray, $recordTypeValue);
         return $this->removeFieldsFromPalettes($result, $removeListArray);
     }

typo3/sysext/backend/Classes/Form/Wizard/SuggestWizardDefaultReceiver.php

@@ -322,9 +322,9 @@ class SuggestWizardDefaultReceiver
             }
 
             $pageIds = array_keys($rows);
-            $pages[] = $pageIds;
+            $pages = array_merge($pages, $pageIds);
         }
-        return array_merge(...$pages);
+        return $pages;
     }
 
     /**

typo3/sysext/backend/Classes/Template/DocumentTemplate.php

@@ -599,14 +599,14 @@ function jumpToUrl(URL) {
         if (is_array($GLOBALS['TBE_STYLES']['skins'])) {
             // loop over all registered skins
             foreach ($GLOBALS['TBE_STYLES']['skins'] as $skinExtKey => $skin) {
-                $skinStylesheetDirs = [$this->stylesheetsSkins];
+                $skinStylesheetDirs = $this->stylesheetsSkins;
                 // Skins can add custom stylesheetDirectories using
                 // $GLOBALS['TBE_STYLES']['skins']['your_extension_key']['stylesheetDirectories']
                 if (is_array($skin['stylesheetDirectories'])) {
-                    $skinStylesheetDirs[] = $skin['stylesheetDirectories'];
+                    $skinStylesheetDirs = array_merge($skinStylesheetDirs, $skin['stylesheetDirectories']);
                 }
                 // Add all registered directories
-                foreach (array_merge(...$skinStylesheetDirs) as $stylesheetDir) {
+                foreach ($skinStylesheetDirs as $stylesheetDir) {
                     // for EXT:myskin/stylesheets/ syntax
                     if (strpos($stylesheetDir, 'EXT:') === 0) {
                         list($extKey, $path) = explode('/', substr($stylesheetDir, 4), 2);

typo3/sysext/backend/Classes/Tree/View/AbstractTreeView.php

@@ -348,7 +348,7 @@ abstract class AbstractTreeView
         $this->initializePositionSaving();
         // Init done:
         $lastMountPointPid = 0;
-        $treeArr = [[]];
+        $treeArr = [];
         // Traverse mounts:
         foreach ($this->MOUNTS as $idx => $uid) {
             // Set first:
@@ -396,10 +396,10 @@ abstract class AbstractTreeView
                     $this->getTree($uid, 999, $depthData);
                 }
                 // Add tree:
-                $treeArr[] = $this->tree;
+                $treeArr = array_merge($treeArr, $this->tree);
             }
         }
-        return $this->printTree(array_merge(...$treeArr));
+        return $this->printTree($treeArr);
     }
 
     /**

typo3/sysext/backend/Classes/Tree/View/FolderTreeView.php

@@ -266,14 +266,14 @@ class FolderTreeView extends AbstractTreeView
         // Get stored tree structure AND updating it if needed according to incoming PM GET var.
         $this->initializePositionSaving();
         // Init done:
-        $treeItems = [[]];
+        $treeItems = [];
         // Traverse mounts:
         foreach ($this->storages as $storageObject) {
             $this->getBrowseableTreeForStorage($storageObject);
             // Add tree:
-            $treeItems[] = $this->tree;
+            $treeItems = array_merge($treeItems, $this->tree);
         }
-        return $this->printTree(array_merge(...$treeItems));
+        return $this->printTree($treeItems);
     }
 
     /**

typo3/sysext/backend/Classes/View/PageLayoutView.php

@@ -3764,21 +3764,21 @@ class PageLayoutView implements LoggerAwareInterface
         $tree->init('AND ' . $perms_clause);
         $tree->makeHTML = 0;
         $tree->fieldArray = ['uid', 'php_tree_stop'];
-        $idList = [[]];
+        $idList = [];
 
         $allowedMounts = !$backendUser->isAdmin() && $id === 0
             ? $backendUser->returnWebmounts()
             : [$id];
 
         foreach ($allowedMounts as $allowedMount) {
-            $idList[] = [$allowedMount];
+            $idList[] = $allowedMount;
             if ($depth) {
                 $tree->getTree($allowedMount, $depth, '');
             }
-            $idList[] = $tree->ids;
+            $idList = array_merge($idList, $tree->ids);
         }
 
-        return array_merge(...$idList);
+        return $idList;
     }
 
     /**

typo3/sysext/backend/Classes/View/PageTreeView.php

@@ -269,7 +269,7 @@ class PageTreeView extends BrowseTreeView
         // Get stored tree structure AND updating it if needed according to incoming PM GET var.
         $this->initializePositionSaving();
         // Init done:
-        $treeArr = [[]];
+        $treeArr = [];
         // Traverse mounts:
         $firstHtml = '';
         foreach ($this->MOUNTS as $idx => $uid) {
@@ -310,9 +310,9 @@ class PageTreeView extends BrowseTreeView
                     $this->getTree($uid);
                 }
                 // Add tree:
-                $treeArr[] = $this->tree;
+                $treeArr = array_merge($treeArr, $this->tree);
             }
         }
-        return $this->printTree(array_merge(...$treeArr));
+        return $this->printTree($treeArr);
     }
 }

typo3/sysext/core/Classes/Core/Bootstrap.php

@@ -540,7 +540,6 @@ class Bootstrap
             // substr is necessary, because the php frontend wraps php code around the cache value
             $routesFromPackages = unserialize(substr($codeCache->get($cacheIdentifier), 6, -2));
         } else {
-            $routesFromPackages = [[]];
             // Loop over all packages and check for a Configuration/Backend/Routes.php file
             $packageManager = GeneralUtility::makeInstance(\TYPO3\CMS\Core\Package\PackageManager::class);
             $packages = $packageManager->getActivePackages();
@@ -549,7 +548,7 @@ class Bootstrap
                 if (file_exists($routesFileNameForPackage)) {
                     $definedRoutesInPackage = require $routesFileNameForPackage;
                     if (is_array($definedRoutesInPackage)) {
-                        $routesFromPackages[] = $definedRoutesInPackage;
+                        $routesFromPackages = array_merge($routesFromPackages, $definedRoutesInPackage);
                     }
                 }
                 $routesFileNameForPackage = $package->getPackagePath() . 'Configuration/Backend/AjaxRoutes.php';
@@ -559,15 +558,12 @@ class Bootstrap
                         foreach ($definedRoutesInPackage as $routeIdentifier => $routeOptions) {
                             // prefix the route with "ajax_" as "namespace"
                             $routeOptions['path'] = '/ajax' . $routeOptions['path'];
-                            $routeOptions['ajax'] = true;
-                            $routesFromPackages[] = [
-                                'ajax_' . $routeIdentifier => $routeOptions,
-                            ];
+                            $routesFromPackages['ajax_' . $routeIdentifier] = $routeOptions;
+                            $routesFromPackages['ajax_' . $routeIdentifier]['ajax'] = true;
                         }
                     }
                 }
             }
-            $routesFromPackages = array_merge(...$routesFromPackages);
             // Store the data from all packages in the cache
             $codeCache->set($cacheIdentifier, serialize($routesFromPackages));
         }

typo3/sysext/core/Classes/Core/ClassLoadingInformationGenerator.php

@@ -69,14 +69,14 @@ class ClassLoadingInformationGenerator
      */
     public function buildClassLoadingInformationForPackage(PackageInterface $package, $useRelativePaths = false)
     {
-        $classMap = [[]];
+        $classMap = [];
         $psr4 = [];
         $packagePath = $package->getPackagePath();
         $manifest = $package->getValueFromComposerManifest();
 
         if (empty($manifest->autoload)) {
             // Legacy mode: Scan the complete extension directory for class files
-            $classMap[] = $this->createClassMap($packagePath, $useRelativePaths, !$this->isDevMode);
+            $classMap = $this->createClassMap($packagePath, $useRelativePaths, !$this->isDevMode);
         } else {
             $autoloadPsr4 = $this->getAutoloadSectionFromManifest($manifest, 'psr-4');
             if (!empty($autoloadPsr4)) {
@@ -91,7 +91,7 @@ class ClassLoadingInformationGenerator
                         }
                         if (!empty($namespaceRealPath) && is_dir($namespaceRealPath)) {
                             // Add all prs-4 classes to the class map for improved class loading performance
-                            $classMap[] = $this->createClassMap($namespacePath, $useRelativePaths, false, $namespacePrefix);
+                            $classMap = array_merge($classMap, $this->createClassMap($namespacePath, $useRelativePaths, false, $namespacePrefix));
                         }
                     }
                 }
@@ -99,12 +99,12 @@ class ClassLoadingInformationGenerator
             $autoloadClassmap = $this->getAutoloadSectionFromManifest($manifest, 'classmap');
             if (!empty($autoloadClassmap)) {
                 foreach ($autoloadClassmap as $path) {
-                    $classMap[] = $this->createClassMap($packagePath . $path, $useRelativePaths);
+                    $classMap = array_merge($classMap, $this->createClassMap($packagePath . $path, $useRelativePaths));
                 }
             }
         }
 
-        return ['classMap' => array_merge(...$classMap), 'psr-4' => $psr4];
+        return ['classMap' => $classMap, 'psr-4' => $psr4];
     }
 
     /**
@@ -219,15 +219,13 @@ class ClassLoadingInformationGenerator
 return array(
 
 EOF;
-        $classMap = [[]];
-        $psr4 = [[]];
+        $classMap = [];
+        $psr4 = [];
         foreach ($this->activeExtensionPackages as $package) {
             $classLoadingInformation = $this->buildClassLoadingInformationForPackage($package, true);
-            $classMap[] = $classLoadingInformation['classMap'];
-            $psr4[] = $classLoadingInformation['psr-4'];
+            $classMap = array_merge($classMap, $classLoadingInformation['classMap']);
+            $psr4 = array_merge($psr4, $classLoadingInformation['psr-4']);
         }
-        $classMap = array_merge(...$classMap);
-        $psr4 = array_merge(...$psr4);
 
         ksort($classMap);
         ksort($psr4);
@@ -290,16 +288,16 @@ EOF;
      */
     public function buildClassAliasMapFile()
     {
-        $aliasToClassNameMapping = [[]];
-        $classNameToAliasMapping = [[]];
+        $aliasToClassNameMapping = [];
+        $classNameToAliasMapping = [];
         foreach ($this->activeExtensionPackages as $package) {
             $aliasMappingForPackage = $this->buildClassAliasMapForPackage($package);
-            $aliasToClassNameMapping[] = $aliasMappingForPackage['aliasToClassNameMapping'];
-            $classNameToAliasMapping[] = $aliasMappingForPackage['classNameToAliasMapping'];
+            $aliasToClassNameMapping = array_merge($aliasToClassNameMapping, $aliasMappingForPackage['aliasToClassNameMapping']);
+            $classNameToAliasMapping = array_merge($classNameToAliasMapping, $aliasMappingForPackage['classNameToAliasMapping']);
         }
         $exportArray = [
-            'aliasToClassNameMapping' => array_merge(...$aliasToClassNameMapping),
-            'classNameToAliasMapping' => array_merge(...$classNameToAliasMapping)
+            'aliasToClassNameMapping' => $aliasToClassNameMapping,
+            'classNameToAliasMapping' => $classNameToAliasMapping
         ];
         $fileContent = '<?php' . chr(10) . 'return ';
         $fileContent .= var_export($exportArray, true);

typo3/sysext/core/Classes/DataHandling/DataHandler.php

@@ -7819,8 +7819,8 @@ class DataHandler implements LoggerAwareInterface
      */
     protected function processClearCacheQueue()
     {
-        $tagsToClear = [[]];
-        $clearCacheCommands = [[]];
+        $tagsToClear = [];
+        $clearCacheCommands = [];
 
         foreach (static::$recordsToClearCacheFor as $table => $uids) {
             foreach (array_unique($uids) as $uid) {
@@ -7832,18 +7832,18 @@ class DataHandler implements LoggerAwareInterface
                 foreach ($pageUids as $originalParent) {
                     list($tagsToClearFromPrepare, $clearCacheCommandsFromPrepare)
                         = $this->prepareCacheFlush($table, $uid, $originalParent);
-                    $tagsToClear[] = $tagsToClearFromPrepare;
-                    $clearCacheCommands[] = $clearCacheCommandsFromPrepare;
+                    $tagsToClear = array_merge($tagsToClear, $tagsToClearFromPrepare);
+                    $clearCacheCommands = array_merge($clearCacheCommands, $clearCacheCommandsFromPrepare);
                 }
             }
         }
 
         /** @var CacheManager $cacheManager */
         $cacheManager = $this->getCacheManager();
-        $cacheManager->flushCachesInGroupByTags('pages', array_keys(array_merge(...$tagsToClear)));
+        $cacheManager->flushCachesInGroupByTags('pages', array_keys($tagsToClear));
 
         // Filter duplicate cache commands from cacheQueue
-        $clearCacheCommands = array_unique(array_merge(...$clearCacheCommands));
+        $clearCacheCommands = array_unique($clearCacheCommands);
         // Execute collected clear cache commands from page TSConfig
         foreach ($clearCacheCommands as $command) {
             $this->clear_cacheCmd($command);

typo3/sysext/core/Classes/DataHandling/Localization/DataMapProcessor.php

@@ -271,12 +271,14 @@ class DataMapProcessor
      */
     protected function sanitizeTranslationItem(DataMapItem $item)
     {
-        $fieldNames = [[]];
+        $fieldNames = [];
         foreach ($item->getApplicableScopes() as $scope) {
-            $fieldNames[] = $this->getFieldNamesForItemScope($item, $scope, false);
+            $fieldNames = array_merge(
+                $fieldNames,
+                $this->getFieldNamesForItemScope($item, $scope, false)
+            );
         }
 
-        $fieldNames = array_merge(...$fieldNames);
         $fieldNameMap = array_combine($fieldNames, $fieldNames);
         // separate fields, that are submitted in data-map, but not defined as custom
         $this->sanitizationMap[$item->getTableName()][$item->getId()] = array_intersect_key(

typo3/sysext/core/Classes/Database/Schema/SchemaMigrator.php

@@ -173,7 +173,7 @@ class SchemaMigrator
     {
         $connectionPool = GeneralUtility::makeInstance(ConnectionPool::class);
         $tables = $this->parseCreateTableStatements($statements);
-        $result = [[]];
+        $result = [];
 
         foreach ($connectionPool->getConnectionNames() as $connectionName) {
             $connectionMigrator = ConnectionMigrator::create(
@@ -181,10 +181,11 @@ class SchemaMigrator
                 $tables
             );
 
-            $result[] = $connectionMigrator->install($createOnly);
+            $lastResult = $connectionMigrator->install($createOnly);
+            $result = array_merge($result, $lastResult);
         }
 
-        return array_merge(...$result);
+        return $result;
     }
 
     /**

typo3/sysext/core/Classes/Localization/Locales.php

@@ -196,18 +196,18 @@ class Locales implements SingletonInterface
      */
     public function getLocaleDependencies($locale)
     {
-        $dependencies = [[]];
+        $dependencies = [];
         if (isset($this->localeDependencies[$locale])) {
-            $dependencies[] = $this->localeDependencies[$locale];
+            $dependencies = $this->localeDependencies[$locale];
             // Search for dependencies recursively
             $localeDependencies = $dependencies;
             foreach ($localeDependencies as $dependency) {
                 if (isset($this->localeDependencies[$dependency])) {
-                    $dependencies[] = $this->getLocaleDependencies($dependency);
+                    $dependencies = array_merge($dependencies, $this->getLocaleDependencies($dependency));
                 }
             }
         }
-        return array_merge(...$dependencies);
+        return $dependencies;
     }
 
     /**

typo3/sysext/core/Classes/Localization/LocalizationFactory.php

@@ -117,18 +117,16 @@ class LocalizationFactory implements \TYPO3\CMS\Core\SingletonInterface
      */
     protected function localizationOverride($fileReference, $languageKey, array &$LOCAL_LANG)
     {
-        $overrides = [[]];
+        $overrides = [];
         $fileReferenceWithoutExtension = $this->store->getFileReferenceWithoutExtension($fileReference);
         $locallangXMLOverride = $GLOBALS['TYPO3_CONF_VARS']['SYS']['locallangXMLOverride'];
         foreach ($this->store->getSupportedExtensions() as $extension) {
             if (isset($locallangXMLOverride[$languageKey][$fileReferenceWithoutExtension . '.' . $extension]) && is_array($locallangXMLOverride[$languageKey][$fileReferenceWithoutExtension . '.' . $extension])) {
-                $overrides[] = $locallangXMLOverride[$languageKey][$fileReferenceWithoutExtension . '.' . $extension];
+                $overrides = array_merge($overrides, $locallangXMLOverride[$languageKey][$fileReferenceWithoutExtension . '.' . $extension]);
             } elseif (isset($locallangXMLOverride[$fileReferenceWithoutExtension . '.' . $extension]) && is_array($locallangXMLOverride[$fileReferenceWithoutExtension . '.' . $extension])) {
-                $overrides[] = $locallangXMLOverride[$fileReferenceWithoutExtension . '.' . $extension];
+                $overrides = array_merge($overrides, $locallangXMLOverride[$fileReferenceWithoutExtension . '.' . $extension]);
             }
         }
-
-        $overrides = array_merge(...$overrides);
         if (!empty($overrides)) {
             foreach ($overrides as $overrideFile) {
                 $languageOverrideFileName = GeneralUtility::getFileAbsFileName($overrideFile);

typo3/sysext/core/Classes/Resource/ResourceCompressor.php

@@ -142,7 +142,7 @@ class ResourceCompressor
                 'allWrap' => ''
             ];
             // place the merged stylesheet on top of the stylesheets
-            $cssFiles[$targetFile] = $concatenatedOptions;
+            $cssFiles = array_merge($cssFiles, [$targetFile => $concatenatedOptions]);
         }
         return $cssFiles;
     }
@@ -194,7 +194,7 @@ class ResourceCompressor
                     'async' => $concatenatedJsFileIsAsync && $allFilesToConcatenateAreAsync,
                 ];
                 // place the merged javascript on top of the JS files
-                $jsFiles[$targetFile] = $concatenatedOptions;
+                $jsFiles = array_merge([$targetFile => $concatenatedOptions], $jsFiles);
             }
         }
         return $jsFiles;

typo3/sysext/core/Classes/Resource/Service/UserFileMountService.php

@@ -121,7 +121,7 @@ class UserFileMountService
         if ($level > 99) {
             return [];
         }
-        $allFolderItems = [[$parentFolder]];
+        $allFolderItems = [$parentFolder];
         $subFolders = $parentFolder->getSubfolders();
         foreach ($subFolders as $subFolder) {
             try {
@@ -129,9 +129,9 @@ class UserFileMountService
             } catch (InsufficientFolderReadPermissionsException $e) {
                 $subFolderItems = [];
             }
-            $allFolderItems[] = $subFolderItems;
+            $allFolderItems = array_merge($allFolderItems, $subFolderItems);
         }
-        return array_merge(...$allFolderItems);
+        return $allFolderItems;
     }
 
     /**