Verify behaviour with APFS

[guruz]

I know we have some issues on desktop (https://github.com/owncloud/client/issues/5650) so you should check your iOS behaviour too :)

https://developer.apple.com/library/content/documentation/FileManagement/Conceptual/APFS_Guide/FAQ/FAQ.html#//apple_ref/doc/uid/TP40016999-CH6-DontLinkElementID_3 "Some differences between how APFS and HFS+ handle filenames include the following:"

Although it might be too late because 10.3 is already out? Especially interesting might be things like emojis or invalid utf8 encodings.