When I have time I will folllow up with the vim guys, I think however that ZFS ACLs are not supported anyway in that vim version (I found some vague comments about...
Yes, I run a test with LD_PRELOAD set, so chmod command would not work (and it wasn't working! I tried), that preserved the ACLS when runing vim with backup mode on.
I have tried this and it is not changing the permissions now.. but that would be expected if chmod is "interfered" like that?
What vim does is take a copy,...