bug#865: 23.0.60; The directory is unsafe today

[Jason Rumney <jasonr@gnu.org>]

Eli Zaretskii wrote:
>> Date: Thu, 04 Sep 2008 07:44:49 +0800
>> From: Jason Rumney <jasonr@gnu.org>
>> CC: 865@emacsbugs.donarmstrong.com, emacs-pretest-bug@gnu.org
>>
>>     
>>>   (or (eql (nth 2 attrs) (user-uid))
>>>       (and (eq system-type 'windows-nt) (eql (nth 2 attrs) (user-gid)))
>>>   
>>>       
>> I am trying to find a solution that will work without Lisp coders 
>> needing to be aware of the strange situation on Windows that files can 
>> be owned by a group.
>>     
>
> I think the only good solution in that venue would be to have a new
> primitive for such tests, and implement it on Windows so that it will
> cater to this special case.  Any other solution is likely to lie about
> the file's security attributes.
>   

We are telling a lie already by attempting to map ACLs to POSIX 
ownership. If we are going to attempt this, then it is better to tell a 
lie that fits with the expectations of POSIX (ie that owners of files 
are individual users). A different API that tells the full story might 
be a good idea, but any new API is only going to be used by future 
developers who know about the API, it cannot fix problems in existing 
Lisp code that might make the same assumptions as server.el.