Another chmod issue on 3.1.7, Win 10.

[Ken Brown]

On 12/24/2020 4:30 PM, Kaz Kylheku via Cygwin wrote:
> Initial conditions:
> 
>    0:BLACKBOX:~/txr$ rm testfile
>    0:BLACKBOX:~/txr$ touch testfile
>    0:BLACKBOX:~/txr$ chmod = testfile
>    0:BLACKBOX:~/txr$ ls -l testfile
>    ---------- 1 kaz kaz 0 Dec 24 13:23 testfile
> 
> Now, light up all the bits, like a Christmas tree---appropriate
> for December 24:
> 
>    0:BLACKBOX:~/txr$ chmod ugo+rwxs testfile
>    0:BLACKBOX:~/txr$ ls -l testfile
>    -rwsrwsrwx 1 kaz kaz 0 Dec 24 13:23 testfile
> 
> Well, almost all the bits: I didn't add "t", but it makes
> no difference. Anyway, so far, so good. Now, punch a hole in
> the group permissions:
> 
>    0:BLACKBOX:~/txr$ ls -l testfile
>    -rws---rwx+ 1 kaz kaz 0 Dec 24 13:23 testfile
> 
> No idea what that + is hinting at, which indicates a problem.

No, it doesn't indicate a problem.  It just means that there's an ACL involved 
in determining the actual permissions.  Do an internet search for "ls plus sign" 
for more information.

> But the group perms did get masked out. Let's keep going to the
> main problem: repeat the second step to turn on all the bits:
> 
>    0:BLACKBOX:~/txr$ chmod ugo+rwxs testfile
>    0:BLACKBOX:~/txr$ ls -l testfile
>    -rws--Srwx+ 1 kaz kaz 0 Dec 24 13:23 testfile
> 
> What??? The expected perms are "-rwsrwsrwx". It did not set the group read
> or write at all, and that funny  + is still hanging around.

I suspect this is the same owner/group issue that I suggested in my reply to 
your other message.

Ken