Re: CVS Emacs fails to remove server.el socket on exit

[Trent Buck]

On Mon, Dec 18, 2006 at 10:14:53AM +0100, Juanma Barranquero wrote:
> On 12/18/06, Trent Buck <address@hidden> wrote:
> 
> >I believe CVS Emacs is not correctly removing the socket file created
> >by server-start (from server.el).
> 
> It is on purpose. Note the following fragment from server.el:
> 
>  ;; Delete the associated connection file, if applicable.
>  ;; This is actually problematic: the file may have been overwritten by
>  ;; another Emacs server in the mean time, so it's not ours any more.
>  ;; (and (process-contact proc :server)
>  ;;      (eq (process-status proc) 'closed)
>  ;;      (ignore-errors (delete-file (process-get proc :server-file))))

I see.

In my .emacs, I change `server-name' to be process-specific, and
create a symlink to the "generic" name:

    ;;; Say I run "bzr commit" in a normal shell, outside of emacs.  I
    ;;; want that to start up a full Emacs.  If it used emacsclient, then
    ;;; buffer would show up on some random Emacs process in some GNU
    ;;; Screen window, and I'd have to hunt it down.
    ;;;
    ;;; HOWEVER, if I run M-x shell in Emacs, and I run "bzr commit" in
    ;;; THERE, I want it to talk to the parent Emacs process (via
    ;;; emacsclient).
    ;;;
    ;;; Since I occasionally have multiple Emacs processes running, I need
    ;;; to change server-name to be process-specific, so the Emacs
    ;;; processes' server-starts won't clobber one another's sockets.
    (setq server-name (format "server%d" (emacs-pid)))
    (let ((x (format "emacsclient -s %s" server-name)))
      (setenv "VISUAL" x)
      (setenv "EDITOR" x))
    (server-start)
    
    ;; emacsclient(1) looks for a socket named "server" by default.  We
    ;; symlink to this file, so that running emacsclient manually from the
    ;; command line will use the more recently opened Emacs.
    ;;
    ;; We don't bother doing this for Emacs 21 because the socket dir is
    ;; too difficult to deduce.
    (when (= emacs-major-version 22)
      (make-symbolic-link
       server-name
       (concat server-socket-dir "/server")
       t))

Is this a sensible approach to adopt as default in CVS Emacs, or would
it have problems for e.g. DOS users (who have no symbolic links)?

If this approach was adopted, `server-sentinel' could happily remove
it's socket file, leaving a broken symlink instead of a defunct
socket.
-- 
Trent Buck, Student Errant

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