[Samba] explorer.exe crashes on security tab access

[Kacper]

Hello,

I've seem to have found what looks like a bug in Samba 4.8.3. It's the same
problem as described in
https://lists.samba.org/archive/samba/2018-March/214589.html. When
accessing the Security tab on files and folder from a share explorer.exe
crashes.

I've been able to track down that it only happens when the primary group of
a file or folder is a Unix group. Using an AD group as the primary group of
files and folders does not crash Windows.

I would appreciate any pointers or assistance in collecting as much
valuable information to create a bug report.

Thanks,
Kacper