bug#14140: 24.3.50; auto-revert-mode does not revert upon invocation

bug#14140: 24.3.50; auto-revert-mode does not revert upon invocation

[Óscar Fuentes]

In a shell:
$ echo hello > foo
$ emacs -Q foo &
$ echo bye > foo

In Emacs:
M-x auto-revert-mode

<the buffer keeps showing "hello">

In the past, after executing auto-revert-mode the buffer was reverted to
the file's current contents. Nowadays, the buffer keeps showing the
file's old contents until the file is modified again.

This is obviously a bug because an unmodified buffer with
auto-revert-mode enabled is supposed to show the current contents of its
associated buffer.


In GNU Emacs 24.3.50.3 (x86_64-unknown-linux-gnu, X toolkit)
 of 2013-03-23 on qcore
Windowing system distributor `The X.Org Foundation', version 11.0.11300000
System Description:	Ubuntu 12.10

Configured using:
 `configure --with-x-toolkit=lucid --without-toolkit-scroll-bars'

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Fundamental

Minor modes in effect:
  auto-revert-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
M-x a u t o SPC r e v e r t SPC m o <tab> <return> 
<f10> <menu-bar> <help-menu> <send-emacs-bug-repor
t>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Auto-Revert mode enabled

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util mail-prsvr mail-utils autorevert time-date tooltip ediff-hook
vc-hooks lisp-float-type mwheel x-win x-dnd tool-bar dnd fontset image
regexp-opt fringe tabulated-list newcomment lisp-mode register page
menu-bar rfn-eshadow timer select scroll-bar mouse jit-lock font-lock
syntax facemenu font-core frame cham georgian utf-8-lang misc-lang
vietnamese tibetan thai tai-viet lao korean japanese hebrew greek
romanian slovak czech european ethiopic indian cyrillic chinese
case-table epa-hook jka-cmpr-hook help simple abbrev minibuffer loaddefs
button faces cus-face macroexp files text-properties overlay sha1 md5
base64 format env code-pages mule custom widget hashtable-print-readable
backquote make-network-process inotify dynamic-setting
font-render-setting x-toolkit x multi-tty emacs)

bug#14140: 24.3.50; auto-revert-mode does not revert upon invocation

[Michael Albinus]

Óscar Fuentes <oscarfv@telefonica.net> writes:

Hi Óscar,

> In a shell:
> $ echo hello > foo
> $ emacs -Q foo &
> $ echo bye > foo
>
> In Emacs:
> M-x auto-revert-mode
>
> <the buffer keeps showing "hello">
>
> In the past, after executing auto-revert-mode the buffer was reverted to
> the file's current contents. Nowadays, the buffer keeps showing the
> file's old contents until the file is modified again.
>
> This is obviously a bug because an unmodified buffer with
> auto-revert-mode enabled is supposed to show the current contents of its
> associated buffer.

auto-revert-mode uses file notifications now. In your scenario, no
notification reaches Emacs.

Likely, when *enabling* auto-revert-mode, it shall be checked whether
something has to be reverted initially. Will see (but not tonight,
rather tomorrow or over the weekend).

Best regards, Michael.

bug#14140: 24.3.50; auto-revert-mode does not revert upon invocation

[Eli Zaretskii]

> From: Óscar Fuentes <oscarfv@telefonica.net>
> Date: Thu, 04 Apr 2013 20:08:00 +0200
> 
> In a shell:
> $ echo hello > foo
> $ emacs -Q foo &
> $ echo bye > foo
> 
> In Emacs:
> M-x auto-revert-mode
> 
> <the buffer keeps showing "hello">
> 
> In the past, after executing auto-revert-mode the buffer was reverted to
> the file's current contents. Nowadays, the buffer keeps showing the
> file's old contents until the file is modified again.

Set auto-revert-use-notify to a nil value before turning on
auto-revert-mode, and the problem goes away (at least for me it did).

bug#14140: 24.3.50; auto-revert-mode does not revert upon invocation

[Óscar Fuentes]

Eli Zaretskii <eliz@gnu.org> writes:

> Set auto-revert-use-notify to a nil value before turning on
> auto-revert-mode, and the problem goes away (at least for me it did).

Same here.

Michael, either the initial check in not executed or it is failing for
some reason. It is normal that no notification reaches Emacs because the
file is modified before auto-revert-mode is enabled.

Let me know if you are interested on running some experiment, obtaining
traces, etc.

bug#14140: 24.3.50; auto-revert-mode does not revert upon invocation

[Michael Albinus]

oscarfv@telefonica.net (Óscar Fuentes) writes:

> Let me know if you are interested on running some experiment, obtaining
> traces, etc.

Not yet, I shall be able to reproduce it myself :-) I'll keep you
informed about progress.

Best regards, Michael.

bug#14140: 24.3.50; auto-revert-mode does not revert upon invocation

[Michael Albinus]

oscarfv@telefonica.net (Óscar Fuentes) writes:

Hi Óscar,

> Let me know if you are interested on running some experiment, obtaining
> traces, etc.

I have committed a patch to the trunk, as #112226. Could you, please,
check?

Best regards, Michael.

bug#14140: 24.3.50; auto-revert-mode does not revert upon invocation

[Óscar Fuentes]

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

> I have committed a patch to the trunk, as #112226. Could you, please,
> check?

It works.

Thanks Michael.

bug#14140: 24.3.50; auto-revert-mode does not revert upon invocation

[Michael Albinus]

oscarfv@telefonica.net (Óscar Fuentes) writes:

>> I have committed a patch to the trunk, as #112226. Could you, please,
>> check?
>
> It works.

Thanks for checking. I'm closing the bug.

> Thanks Michael.

Best regards, Michael.