bug#22313: 24.3; on global-font-lock-mode's documentation

bug#22313: 24.3; on global-font-lock-mode's documentation

[dbastos]

I ran emacs -Q and so font-lock-mode came up enabled.  Good.  I then ran

  (global-font-lock-mode nil)

and it did turn off.  Looking at the documentation, I read the passage
below.  It makes me think that the argument of nil, since that's not
positive, would disable font-lock-mode, but it doesn't.  The function
really needs a negative argument.  The documentation should be fixed.

--8<---------------cut here---------------start------------->8---
global-font-lock-mode is an interactive compiled Lisp function in
`font-core.el'.

(global-font-lock-mode &optional ARG)

Toggle Font-Lock mode in all buffers.
With prefix ARG, enable Global-Font-Lock mode if ARG is positive;
otherwise, disable it.  If called from Lisp, enable the mode if
ARG is omitted or nil.

Font-Lock mode is enabled in all buffers where
`turn-on-font-lock-if-desired' would do it.
See `font-lock-mode' for more information on Font-Lock mode.
--8<---------------cut here---------------end--------------->8---



In GNU Emacs 24.3.1 (i386-mingw-nt6.1.7601)
 of 2013-03-17 on MARVIN
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --with-gcc (4.7) --cflags
 -ID:/devel/emacs/libs/libXpm-3.5.8/include
 -ID:/devel/emacs/libs/libXpm-3.5.8/src
 -ID:/devel/emacs/libs/libpng-dev_1.4.3-1/include
 -ID:/devel/emacs/libs/zlib-dev_1.2.5-2/include
 -ID:/devel/emacs/libs/giflib-4.1.4-1/include
 -ID:/devel/emacs/libs/jpeg-6b-4/include
 -ID:/devel/emacs/libs/tiff-3.8.2-1/include
 -ID:/devel/emacs/libs/gnutls-3.0.9/include
 -ID:/devel/emacs/libs/libiconv-1.13.1-1-dev/include
 -ID:/devel/emacs/libs/libxml2-2.7.8/include/libxml2'

Important settings:
  value of $LANG: PTB
  locale-coding-system: cp1252
  default enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  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:
( g l o b a l - f o n t - l o c k - m o d e SPC n i 
l ) C-x C-e <return> <return> C-u C-h f g l o b a l 
- f o n t - l o c k - m o d e <return> M-x i n s e 
r t SPC b u f <tab> <return> <return> C-x 1 <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <menu-bar> 
<help-menu> <send-emacs-bug-report>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
t
Type C-x 1 to delete the help window.
Mark set

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
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 help-mode easymenu help-fns time-date tooltip
ediff-hook vc-hooks lisp-float-type mwheel dos-w32 ls-lisp
w32-common-fns disp-table w32-win w32-vars 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
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base64 format env code-pages mule custom widget hashtable-print-readable
backquote make-network-process w32 multi-tty emacs)

bug#22313: 24.3; on global-font-lock-mode's documentation

[Eli Zaretskii]

> From: dbastos@toledo.com
> Date: Tue, 05 Jan 2016 15:39:36 -0200
> 
> I ran emacs -Q and so font-lock-mode came up enabled.  Good.  I then ran
> 
>   (global-font-lock-mode nil)
> 
> and it did turn off.  Looking at the documentation, I read the passage
> below.  It makes me think that the argument of nil, since that's not
> positive, would disable font-lock-mode, but it doesn't.  The function
> really needs a negative argument.  The documentation should be fixed.

Sorry, I don't understand which part of the documentation needs
fixing.  Can you clarify?

This part:

> If called from Lisp, enable the mode if ARG is omitted or nil.

clearly says that calling the function with nil as its argument
_enables_ the mode, not disables it.

As for being not positive, nil is not a number, so its sign is really
undefined, I think.

bug#22313: 24.3; on global-font-lock-mode's documentation

[Daniel Bastos]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: dbastos@toledo.com
>> Date: Tue, 05 Jan 2016 15:39:36 -0200
>> 
>> I ran emacs -Q and so font-lock-mode came up enabled.  Good.  I then ran
>> 
>>   (global-font-lock-mode nil)
>> 
>> and it did turn off.  Looking at the documentation, I read the passage
>> below.  It makes me think that the argument of nil, since that's not
>> positive, would disable font-lock-mode, but it doesn't.  The function
>> really needs a negative argument.  The documentation should be fixed.
>
> Sorry, I don't understand which part of the documentation needs
> fixing.  Can you clarify?
>
> This part:
>
>> If called from Lisp, enable the mode if ARG is omitted or nil.
>
> clearly says that calling the function with nil as its argument
> _enables_ the mode, not disables it.
>
> As for being not positive, nil is not a number, so its sign is really
> undefined, I think.

I'm really sorry.  I didn't pay enough attention.  For what it's worth,
I suppose the "otherwise" threw me off completely and the following
sentences didn't take effect in my brain.  I'm sorry.

bug#22313: 24.3; on global-font-lock-mode's documentation

[Eli Zaretskii]

> From: Daniel Bastos <dbastos@toledo.com>
> Cc: 22313@debbugs.gnu.org
> Date: Tue, 05 Jan 2016 17:17:35 -0200
> 
> I'm really sorry.  I didn't pay enough attention.  For what it's worth,
> I suppose the "otherwise" threw me off completely and the following
> sentences didn't take effect in my brain.  I'm sorry.

No need to apologize, mistakes do happen.  I'm glad we had this
figured out.

I'm closing this bug report, then.

Thanks.