With /sudo::/etc instead of /etc, files are not conf mode by default

With /sudo::/etc instead of /etc, files are not conf mode by default

[trentbuck]

The file /etc/default/tftpd-hpa uses conf mode by default, presumably
due to auto-mode-alist.  However, opening the same file with TRAMP's
sudo method: /sudo::/etc/default/tftpd-hpa, causes it to be in
fundamental mode.  Presumably this is because the auto-mode-alist
entry uses ^/ to match the root directory or similar.

In GNU Emacs 22.1.1 (x86_64-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2007-07-07 on nautilus, modified by Debian
configured using `configure  '--build=x86_64-linux-gnu' '--host=x86_64-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib' '--localstatedir=/var/lib' '--infodir=/usr/share/info' '--mandir=/usr/share/man' '--with-pop=yes' '--enable-locallisppath=/etc/emacs22:/etc/emacs:/usr/local/share/emacs/22.1/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/22.1/site-lisp:/usr/share/emacs/site-lisp:/usr/share/emacs/22.1/leim' '--with-x=yes' '--with-x-toolkit=athena' '--with-toolkit-scroll-bars' 'build_alias=x86_64-linux-gnu' 'host_alias=x86_64-linux-gnu' 'CFLAGS=-DDEBIAN -g -O2''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: C
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_AU.utf8
  locale-coding-system: utf-8
  default-enable-multibyte-characters: t

Major mode: Fundamental

Minor modes in effect:
  xterm-mouse-mode: t
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  delete-selection-mode: t
  encoded-kbd-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  unify-8859-on-encoding-mode: t
  utf-translate-cjk-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

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Re: With /sudo::/etc instead of /etc, files are not conf mode by default

[Michael Albinus]

trentbuck@gmail.com writes:

> The file /etc/default/tftpd-hpa uses conf mode by default, presumably
> due to auto-mode-alist.  However, opening the same file with TRAMP's
> sudo method: /sudo::/etc/default/tftpd-hpa, causes it to be in
> fundamental mode.  Presumably this is because the auto-mode-alist
> entry uses ^/ to match the root directory or similar.

The following patch should fix it. It will appear also in Emacs 22.2.

Thanks for reporting, and best regards, Michael.

Index: lisp/files.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/files.el,v
retrieving revision 1.896.2.5
retrieving revision 1.896.2.11
diff -u -u -r1.896.2.5 -r1.896.2.11
--- lisp/files.el       22 May 2007 11:41:33 -0000      1.896.2.5
+++ lisp/files.el       5 Aug 2007 08:57:24 -0000       1.896.2.11
@@ -2254,7 +2254,12 @@
     ;; Next compare the filename against the entries in auto-mode-alist.
     (unless done
       (if buffer-file-name
-         (let ((name buffer-file-name))
+         (let ((name buffer-file-name)
+               (remote-id (file-remote-p buffer-file-name)))
+           ;; Remove remote file name identification.
+           (when (and (stringp remote-id)
+                      (string-match remote-id name))
+             (setq name (substring name (match-end 0))))
            ;; Remove backup-suffixes from file name.
            (setq name (file-name-sans-versions name))
            (while name

Re: With /sudo::/etc instead of /etc, files are not conf mode by default

[Andreas Schwab]

Michael Albinus <michael.albinus@gmx.de> writes:

> -         (let ((name buffer-file-name))
> +         (let ((name buffer-file-name)
> +               (remote-id (file-remote-p buffer-file-name)))
> +           ;; Remove remote file name identification.
> +           (when (and (stringp remote-id)
> +                      (string-match remote-id name))

The remote-id is not a regex.  And tramp does not even return a string,
so it won't help here anyway.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: With /sudo::/etc instead of /etc, files are not conf mode by default

[Michael Albinus]

Andreas Schwab <schwab@suse.de> writes:

> Michael Albinus <michael.albinus@gmx.de> writes:
>
>> -         (let ((name buffer-file-name))
>> +         (let ((name buffer-file-name)
>> +               (remote-id (file-remote-p buffer-file-name)))
>> +           ;; Remove remote file name identification.
>> +           (when (and (stringp remote-id)
>> +                      (string-match remote-id name))
>
> The remote-id is not a regex.

Right. It shall be (regexp-quote (file-remote-p buffer-file-name))

> And tramp does not even return a string, so it won't help here anyway.

Grr, that's a change in Tramp 2.1, which has been put in the Emacs
trunk.

Because it doesn't harm, I'll change the return value format of
tramp-handle-file-remote-p in EMACS_22_BASE as well.

> Andreas.

Best regards, Michael (who should be more careful on a sunny Sunday afternoon).