Created attachment 17208 [details]
4.14.12 client log
If both of these options are set:
fruit:encoding = native
fruit:delete_empty_adfiles = yes
...then pasting folder icons in the macOS Finder won't work.
When fruit:resource = file, two files are created inside the folder:
On Samba 4.14.12 the '._Icon'$'\r' is not seen on the server, assumed to be immediately removed after creation.
On Samba 4.15.15 the '._Icon'$'\r' file is there but the folder icon doesn't appear. Folder in question can't be deleted from the client side because of a file-in-use error.
Switching to fruit:encoding = private restores functionality and icon creation works again.
Attached are two log files from 4.14.12 and 4.15.5 showing the following procedure:
1. Share opened
2. folder created
3. Standard macOS folder icon pasted to the created folder
4. Try to delete the created folder (only 4.15.5)
5. Share disconnected
Created attachment 17209 [details]
4.14.5 client log