Re: Patch for filesystems that do not support chmod.

[Jesper Harder <harder@ifa.au.dk>]

Paul Stodghill <stodghil@cs.cornell.edu> writes:

>> If XEmacs+cygwin is the odd man out, I think it would be better to
>> make it consistant with the other ports.
>
> XEmacs will raise an exception on any platform when the call to chmod
> fails.

OK, I'm just surprised that we haven't seen this problem before --
some of those set-file-modes lines have been there for a long time,
AFAIK.

Does somone know if Emacs behaves in the same way as XEmacs?

> This is not a platform bug. IMO, Gnus should not request a file mode
> that the underlying filesystem cannot support.

I don't know ... if you're requesting something which the semantics of
the file system doesn't support, I think it's legitimate to just do
something reasonable and not throw an error -- e.g. if you request +x
on ms-windows then it could safely be ignored because all files on
ms-windows are executable anyway.

The Common Lisp standard recommends this type of approach:

  An implementation is required to recognize all of the ‘open’ keyword
  options and to do something reasonable in the context of the host
  operating system.  For example, if a file system does not support
  distinct file versions and does not distinguish the notions of
  deletion and expunging, :new-version might be treated the same as
  :rename or :supersede, and :rename-and-delete might be treated the
  same as :supersede.

-- 
Jesper Harder                                <http://purl.org/harder/>