TYPO3 Core

FAL seems to behave weird on folders starting (or only consisting of) with umlauts.

Umlauts seem to be trimmed only at the start. For example: A folder created with the name "ÄÖABC" shows up as "ABC" in the filelist, but the actual name in the filesystem is "ÄÖABC".
A folder only consisting of umlauts, for example "ÄÖÜ", either shows with the parents folder name ("test/ÄÖÜ" shows as "test/test") or with "[no title]" when created at the file storages root level. The foldername in the filesystem is correct though. Multiple folders only consisting of umlauts ("ÄÖÜ", "ÖÄÜ", "ÜÖÄ") in one folder show up as a single folder, with unknown content (either none or maybe of one of the folder).
Foldernames like "KÖABC" seem to work fine though.