When using S3 as primary storage, transferring ownership with the `--move` option fail with the following error:
`SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '8-45b963397aa40d4a0063e0d85e4fe7a1' for key 'fs_storage_path_hash'`
The `--move` option moves the entire home folder from one account to another.
The error means that the move failed because the destination folder already exist in `oc_filecache`.
- With S3 as primary storage, folders only exists as entries in `oc_filecache`.
- With S3 as primary storage, `moveFromStorage(...)` only moves the cache entry, as nothing needs to be moved on disk. This cache move does not delete potentially pre-existing destination folder.
- With Local storage, `moveFromStorage(...)` calls `rename(...)` which delete pre-existing folder.
- `transfer(...)`: 687a4d9ac7/apps/files/lib/Service/OwnershipTransferService.php (L112)
- `oneTimeUserSetup(...)`: 687a4d9ac7/lib/private/Files/SetupManager.php (L261-L262)
- `mkdir(...)`: 687a4d9ac7/lib/private/Files/ObjectStore/ObjectStoreStorage.php (L91-L135)
- `moveFromStorage(...)`: 687a4d9ac7/lib/private/Files/ObjectStore/ObjectStoreStorage.php (L635-L636)
Delete pre-existing folder in `moveFromStorage(...)`
Signed-off-by: Louis Chemineau <louis@chmn.me>