TYPO3 Core

When migrating a website from 4.5 to 6.2, the upgrade wizard does not fully initialize the automatically created FAL storage as it does not create any processing folders. This becomes an issue if getFile is called on an instance of ResourceStorage which has evaluatePermissions set to true, which is the case if e.g. dam_falmigration is being run from CLI with command php typo3/cli_dispatch.phpsh extbase dammigration:migratedamrecords. This results in a loop inside ResourceStorage; with custom debugging output to trace the loop (each number corresponds to a specific function, described on the a-line, each character to another line in that function):

1a entry TYPO3\CMS\Core\Resource\ResourceStorage::getFile, uid 1, identifier user_upload/folder/file.jpg
2a entry TYPO3\CMS\Core\Resource\ResourceFactory::getFileObjectByStorageAndIdentifier, uid 1 file identifier user_upload/folder/file.jpg
2b checking $storage->isWithinProcessingFolder($fileIdentifier)
3a entry TYPO3\CMS\Core\Resource\ResourceStorage::isWithinProcessingFolder with identifier user_upload/folder/file.jpg
3b starting iteration over getProcessingFolders()
4a entry TYPO3\CMS\Core\Resource\ResourceStorage::getProcessingFolders
4b instantiation of TYPO3\CMS\Core\Resource\StorageRepository
4c find all on storage repository
4d iterate over all storages
4e storage uid 1, name fileadmin/ (auto-created)
5a entry TYPO3\CMS\Core\Resource\ResourceStorage::getProcessingFolder
5b processing folder is not set
5c default set
5e processingfolder is _processed_
5g checking processing folder _processed_
5h creating folder
6a entry TYPO3\CMS\Core\Resource\ResourceStorage::createFolder
6b parent folder is null
   => using root level folder 
6d going to check if add is a permitted folder action
7a entry TYPO3\CMS\Core\Resource\ResourceStorage::checkFolderActionPermission; checking folder action add, folder identifier: /
7c folder === null?
7e read check
7g write check
7h $isWriteCheck = TRUE
7i Check 2: Does the user has the right to perform the action?
8a entry TYPO3\CMS\Core\Resource\ResourceStorage::isWithinFileMountBoundaries
8c $this->evaluatePermissions true
8e get identifier
8f identifier: /, next call is isWithinProcessingFolder
3a entry TYPO3\CMS\Core\Resource\ResourceStorage::isWithinProcessingFolder with identifier /
3b starting iteration over getProcessingFolders()
4a entry TYPO3\CMS\Core\Resource\ResourceStorage::getProcessingFolders
4b instantiation of TYPO3\CMS\Core\Resource\StorageRepository
4c find all on storage repository
4d iterate over all storages
4e storage uid 1, name fileadmin/ (auto-created)
5a entry TYPO3\CMS\Core\Resource\ResourceStorage::getProcessingFolder
5b processing folder is not set
5c default set
5e processingfolder is _processed_
5g checking processing folder _processed_
5h creating folder
6a entry TYPO3\CMS\Core\Resource\ResourceStorage::createFolder
6b parent folder is null
   => using root level folder 
6d going to check if add is a permitted folder action
7a entry TYPO3\CMS\Core\Resource\ResourceStorage::checkFolderActionPermission; checking folder action add, folder identifier: /
...

What happens is that TYPO3\CMS\Core\Resource\ResourceStorage::getFile implicitely checks if processing folders have already been created but they haven't yet. Using isWithinProcessingFolder, TYPO3\CMS\Core\Resource\ResourceStorage::checkFolderActionPermission then checks if the storage's root folder / belongs to the processing folder. Since evaluatePermissions is true, this results in getting the processing folders yet again in an inifinite recursion as the processing folder still not exists, permissions are being checked again and everything repeats.

When the filelist module is being called for the first time by a backend user, the same debugging code produces a partial (incompletely commented) output of:

7a entry TYPO3\CMS\Core\Resource\ResourceStorage::checkFolderActionPermission; checking folder action read, folder identifier: /
7c folder === null?
7e read check
7f $isReadCheck = TRUE
7g write check
7i Check 2: Does the user has the right to perform the action?
8a entry TYPO3\CMS\Core\Resource\ResourceStorage::isWithinFileMountBoundaries
8b !$this->evaluatePermissions
7k
7m
7o
7p
7r
7t
7a entry TYPO3\CMS\Core\Resource\ResourceStorage::checkFolderActionPermission; checking folder action read, folder identifier: /templates/
7c folder === null?
7e read check
7f $isReadCheck = TRUE
7g write check
7i Check 2: Does the user has the right to perform the action?
8a entry TYPO3\CMS\Core\Resource\ResourceStorage::isWithinFileMountBoundaries
8b !$this->evaluatePermissions
7k
7m
7o
7p
7r
7t
7a entry TYPO3\CMS\Core\Resource\ResourceStorage::checkFolderActionPermission; checking folder action read, folder identifier: /user_upload/
7c folder === null?
7e read check
7f $isReadCheck = TRUE
7g write check
7i Check 2: Does the user has the right to perform the action?
8a entry TYPO3\CMS\Core\Resource\ResourceStorage::isWithinFileMountBoundaries
8b !$this->evaluatePermissions
7k
7m
7o
7p
7r
7t
7a entry TYPO3\CMS\Core\Resource\ResourceStorage::checkFolderActionPermission; checking folder action read, folder identifier: /_temp_/
7c folder === null?
7e read check
7f $isReadCheck = TRUE
7g write check
7i Check 2: Does the user has the right to perform the action?
8a entry TYPO3\CMS\Core\Resource\ResourceStorage::isWithinFileMountBoundaries
8b !$this->evaluatePermissions
7k
7m
7o
7p
7r
7t
4a entry TYPO3\CMS\Core\Resource\ResourceStorage::getProcessingFolders
4b instantiation of TYPO3\CMS\Core\Resource\StorageRepository
4c find all on storage repository
4d iterate over all storages
4e storage uid 1, name fileadmin/ (auto-created)
5a entry TYPO3\CMS\Core\Resource\ResourceStorage::getProcessingFolder
5b processing folder is not set
5c default set
5e processingfolder is _processed_
5g checking processing folder _processed_
5h creating folder
6a entry TYPO3\CMS\Core\Resource\ResourceStorage::createFolder
6b parent folder is null
   => using root level folder 
6d going to check if add is a permitted folder action
7a entry TYPO3\CMS\Core\Resource\ResourceStorage::checkFolderActionPermission; checking folder action add, folder identifier: /
7c folder === null?
7e read check
7g write check
7h $isWriteCheck = TRUE
7i Check 2: Does the user has the right to perform the action?
8a entry TYPO3\CMS\Core\Resource\ResourceStorage::isWithinFileMountBoundaries
8b !$this->evaluatePermissions
7k
7m
7o
7p
7r
7t
6f permitted
6g creating folder $this->getDriver()->createFolder($folderName = "_processed_", $parentFolder->getIdentifier() = "/", TRUE)
6h now getting folder /_processed_/
7a entry TYPO3\CMS\Core\Resource\ResourceStorage::checkFolderActionPermission; checking folder action read, folder identifier: /_processed_/
7c folder === null?
7e read check
7f $isReadCheck = TRUE
7g write check
7i Check 2: Does the user has the right to perform the action?
8a entry TYPO3\CMS\Core\Resource\ResourceStorage::isWithinFileMountBoundaries
8b !$this->evaluatePermissions
7k
7m
7o
7p
7r
7t
6i emitting post folder add signal
6j done

It's visible that certain folders are initially created only when first checked by the filelist module. Note that there is no line 8c $this->evaluatePermissions true if filelist is called, so evaluatePermissions is false. This prevents the loop that's happening on CLI.

Afterwards, dam_falmigration does work as expected as the processing folder has already been created and the looping check is no longer performed:

1a entry TYPO3\CMS\Core\Resource\ResourceStorage::getFile, uid 1, identifier user_upload/folder/file.jpg
2a entry TYPO3\CMS\Core\Resource\ResourceFactory::getFileObjectByStorageAndIdentifier, uid 1 file identifier user_upload/folder/file.jpg
2b checking $storage->isWithinProcessingFolder($fileIdentifier)
3a entry TYPO3\CMS\Core\Resource\ResourceStorage::isWithinProcessingFolder with identifier user_upload/folder/file.jpg
3b starting iteration over getProcessingFolders()
4a entry TYPO3\CMS\Core\Resource\ResourceStorage::getProcessingFolders
4b instantiation of TYPO3\CMS\Core\Resource\StorageRepository
4c find all on storage repository
4d iterate over all storages
4e storage uid 1, name fileadmin/ (auto-created)
5a entry TYPO3\CMS\Core\Resource\ResourceStorage::getProcessingFolder
5b processing folder is not set
5c default set
5e processingfolder is _processed_
5g checking processing folder _processed_
5i folder already exists
5j got data

dam_falmigration does not manipulate evaluatePermissions, so this appears to be a bug in Core...

I could imagine two ways to fix this:

1. When the upgrade wizard is creating a FAL storage for the first time, it should initialize all folders that would otherwise only be created upon entering filelist module for the first time. Or:
2. checkFolderActionPermission should skip the isWithinProcessingFolder check if the storage root folder / is being checked as the expected result should always be false? Note that this assumption should be verified by the FAL/Core team; I'm primarily a user and don't know much about those internals of TYPO3. :)

A workaround, obviously, is to call the BE module filelist immediately upon migration, before trying to do anything else. But that shouldn't be necessary in my opinion - what's the upgrade wizard for?