GNU bug report logs - #26317
26.0.50; Small incompatibility in ibuffer.el (ibuffer-compile-format)

Previous Next

Full log

View this message in rfc822 format

From: help-debbugs <at> gnu.org (GNU bug Tracking System)
To: Mark Oteiza <mvoteiza <at> udel.edu>
Cc: tracker <at> debbugs.gnu.org
Subject: bug#26317: closed (26.0.50; Small incompatibility in ibuffer.el
 (ibuffer-compile-format))
Date: Fri, 31 Mar 2017 00:26:02 +0000

[Message part 1 (text/plain, inline)]

Your message dated Thu, 30 Mar 2017 20:25:06 -0400
with message-id <8737dumgwt.fsf <at> holos>
and subject line Re: bug#26317: 26.0.50; Small incompatibility in ibuffer.el (ibuffer-compile-format)
has caused the debbugs.gnu.org bug report #26317,
regarding 26.0.50; Small incompatibility in ibuffer.el (ibuffer-compile-format)
to be marked as done.

(If you believe you have received this mail in error, please contact
help-debbugs <at> gnu.org.)


-- 
26317: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=26317
GNU Bug Tracking System
Contact help-debbugs <at> gnu.org with problems

[Message part 2 (message/rfc822, inline)]

From: John Mastro <john.b.mastro <at> gmail.com>
To: bug-gnu-emacs <at> gnu.org
Subject: 26.0.50; Small incompatibility in ibuffer.el (ibuffer-compile-format)
Date: Thu, 30 Mar 2017 16:07:59 -0700

In commit 7e2a8b1, ibuffer.el was change to use `string-width' in a couple
places where it previously used `length'. The result is that custom columns
which can return nil, which worked in Emacs 25, will now cause an error.

To reproduce, run `emacs -Q', yank the following into *scratch*, and evaluate
it:

    (require 'ibuffer)

    (define-ibuffer-column my-column
      (:name "X")
      (and (equal (buffer-name) "*scratch*") "Y"))

    (setq ibuffer-formats '((mark modified read-only
                                  " " (name 18 18 :left :elide)
                                  " " (my-column 5 5 :left)
                                  " " filename-and-process)))

    (ibuffer)

It works in Emacs 25, but in Emacs 26 an error is signaled:

    Debugger entered--Lisp error: (wrong-type-argument stringp nil)
      string-width(nil)

I came across this because I use the `ibuffer-vc' package, which defines a
column (`vc-status') whose implementation returns nil for some buffers (by
default, non-file-visiting buffers and buffers visiting remote files).

I will follow up with a patch in a separate email (so I can include the bug
number in the commit message).

        John

[Message part 3 (message/rfc822, inline)]

From: Mark Oteiza <mvoteiza <at> udel.edu>
To: John Mastro <john.b.mastro <at> gmail.com>
Cc: 26317-done <at> debbugs.gnu.org
Subject: Re: bug#26317: 26.0.50;
 Small incompatibility in ibuffer.el (ibuffer-compile-format)
Date: Thu, 30 Mar 2017 20:25:06 -0400

John Mastro <john.b.mastro <at> gmail.com> writes:

> John Mastro <john.b.mastro <at> gmail.com> wrote:
>> In commit 7e2a8b1, ibuffer.el was change to use `string-width' in a couple
>> places where it previously used `length'. The result is that custom columns
>> which can return nil, which worked in Emacs 25, will now cause an error.
>
> I've attached a patch that fixes this. Rather than touching the calls to
> `string-width' directly, it translates nil to the empty string. Either
> way restores compatibility with Emacs 25, but translating nil to the
> empty string seems preferable in that it saves later code from caring.
>
> Even though it's a tiny change, I'm not a regular contributor or
> particularly familiar with ibuffer's implementation, so any review is
> appreciated. My copyright assignment is on file.

LGTM.  Sorry for breaking it, and thanks for the fix!

Applied as eeaa707.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.