bug#7645: 23.2; ido commands failed to execute if there is some killed buffer

bug#7645: 23.2; ido commands failed to execute if there is some killed buffer

[Abaw]

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Hi maintainers,

ido commands that finally calls ``ido-make-buffer-list'' would fail to
execute if there is some killed buffer returned by
``buffer-list''. Because (buffer-name a-killed-buffer) will return nil,
``ido-ignore-item-p'' fail to treat it as a stream. My solution is to
return non-nil if name passed to ``ido-ignore-item-p'' is nil.

The attachment is the patch I made for ido.el.


In GNU Emacs 23.2.1 (i486-pc-linux-gnu, GTK+ Version 2.20.0)
of 2010-08-15 on raven, modified by Debian
Windowing system distributor `The X.Org Foundation', version 11.0.60900000
configured using `configure '--build' 'i486-linux-gnu' '--build'
'i486-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/emacs23:/etc/emacs:/usr/local/share/emacs/23.2/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.2/site-lisp:/usr/share/emacs/site-lisp:/usr/share/emacs/23.2/leim'
'--with-x=yes' '--with-x-toolkit=gtk' '--with-toolkit-scroll-bars'
'build_alias=i486-linux-gnu' 'CFLAGS=-DDEBIAN -g -O2' 'LDFLAGS=-g'
'CPPFLAGS=''

Important settings:
value of $LC_ALL: nil
value of $LC_COLLATE: nil
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_US.UTF-8
value of $XMODIFIERS: nil
locale-coding-system: utf-8-unix
default enable-multibyte-characters: t

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--- ido.orig.el	2010-12-15 13:44:36.000000000 +0800
+++ ido.el	2010-12-15 13:44:49.000000000 +0800
@@ -3768,7 +3768,8 @@
 
 (defun ido-ignore-item-p (name re-list &optional ignore-ext)
   ;; Return t if the buffer or file NAME should be ignored.
-  (or (member name ido-ignore-item-temp-list)
+  (or (null name)
+      (member name ido-ignore-item-temp-list)
       (and
        ido-process-ignore-lists re-list
        (save-match-data

bug#7645: 23.2; ido commands failed to execute if there is some killed buffer

[Glenn Morris]

Abaw wrote:

> ido commands that finally calls ``ido-make-buffer-list'' would fail
> to execute if there is some killed buffer returned by ``buffer-list''.

But buffer-list doesn't return killed buffers:
"Return a list of all existing live buffers."

?

bug#7645: Fwd: bug#7645: 23.2; ido commands failed to execute if there is some killed buffer

[Abaw]

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---------- Forwarded message ----------
From: Abaw <abawwu@gmail.com>
Date: Wed, Dec 15, 2010 at 11:29 PM
Subject: Re: bug#7645: 23.2; ido commands failed to execute if there is some
killed buffer
To: Glenn Morris <rgm@gnu.org>


Hi,
It rarely(less than 1 time per month) returns killed buffers, but it does.
Maybe some of my used packages referenced the killed buffers.

The elisp reference manual has mentioned about this behavior:
http://www.gnu.org/software/emacs/manual/html_node/elisp/Killing-Buffers.html#Killing-Buffers

The buffer object for the buffer that has been killed remains in existence
as long as anything refers to it, but it is specially marked so that you
cannot make it current or display it. Killed buffers retain their identity,
however; if you kill two distinct buffers, they remain distinct according
to eq although both are dead.
Sincerely yours,
Ken.

On Wed, Dec 15, 2010 at 4:29 PM, Glenn Morris <rgm@gnu.org> wrote:

> Abaw wrote:
>
> > ido commands that finally calls ``ido-make-buffer-list'' would fail
> > to execute if there is some killed buffer returned by ``buffer-list''.
>
> But buffer-list doesn't return killed buffers:
> "Return a list of all existing live buffers."
>
> ?
>

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bug#7645: Fwd: bug#7645: 23.2; ido commands failed to execute if there is some killed buffer

[Chong Yidong]

Abaw <abawwu@gmail.com> writes:

> [buffer-list] rarely(less than 1 time per month) returns killed
> buffers, but it does.  Maybe some of my used packages referenced the
> killed buffers.

If so, that would be a bug.  `buffer-list' returns the contents of a
list of live buffers maintained internally by Emacs.  When a buffer is
killed, it should be simultaneously removed from this internal list.

> The elisp reference manual has mentioned about this behavior:
> http://www.gnu.org/software/emacs/manual/html_node/elisp/Killing-Buffers.
> html#Killing-Buffers
>
> The buffer object for the buffer that has been killed remains in
> existence as long as anything refers to it, but it is specially marked
> so that you cannot make it current or display it. Killed buffers
> retain their identity, however; if you kill two distinct buffers, they
> remain distinct according to eq although both are dead.

This is a separate issue.  The buffer object remains in existence, but
it should always be removed from the list of live buffers.

Do you happen to have a Lisp backtrace of this error?

bug#7645: 23.2; ido commands failed to execute if there is some killed buffer

[Leo]

On 2011-01-23 04:03 +0800, Chong Yidong wrote:
> Abaw <abawwu@gmail.com> writes:
>
>> [buffer-list] rarely(less than 1 time per month) returns killed
>> buffers, but it does.  Maybe some of my used packages referenced the
>> killed buffers.
>
> If so, that would be a bug.  `buffer-list' returns the contents of a
> list of live buffers maintained internally by Emacs.  When a buffer is
> killed, it should be simultaneously removed from this internal list.

I have seen this bug too due to (buffer-list t) returning killed
buffers. Unfortunately this isn't easy to reproduce.

Leo

bug#7645: 23.2; ido commands failed to execute if there is some killed buffer

[Drew Adams]

> >> [buffer-list] rarely(less than 1 time per month) returns killed
> >> buffers, but it does.  Maybe some of my used packages 
> >> referenced the killed buffers.
> 
> I have seen this bug too due to (buffer-list t) returning killed
> buffers. Unfortunately this isn't easy to reproduce.

1+

Happens to me too, and it's not so rare as once a month.
This has been mentioned in other bug threads, BTW.
Haven't seen a recipe yet.

bug#7645: 23.2; ido commands failed to execute if there is some killed buffer

[martin rudalics]

 > I have seen this bug too due to (buffer-list t) returning killed
 > buffers. Unfortunately this isn't easy to reproduce.

Calling `buffer-list' with argument t is like calling it with no
argument at all ;-)

BTW, I'm running all my Emacsen for more than a month with

(defun check-buffer-list ()
   (dolist (buffer (buffer-list))
     (unless (buffer-live-p buffer)
       (message "Dead buffer %s" buffer))))

(add-hook 'post-command-hook 'check-buffer-list t)

and didn't find anything so far.  So please check whether the behavior
you observe might be caused by some other function.

martin