bug#1722: Meta-Digit not working for info command

bug#1722: Meta-Digit not working for info command

[Bruce Korb]

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:
=================================================================================

CF: email from help-gnu-emacs

From: "Drew Adams" <drew.adams@oracle.com>
To: "'Bruce Korb'" <bruce.korb@gmail.com>, <help-gnu-emacs@gnu.org>
References: <4956B2A5.2050106@gmail.com>
Subject: RE: How can I select a .info file for info mode?
Date: Sat, 27 Dec 2008 23:50:51 -0800

> It used to be the case that ``ESC-2 CTL-h i'' gave me the opportunity
> to select the .info file to use for info mode.  Not any more.
> Plowing through the docs doesn't give me a good enough hint about
> how to do it either.  Please tell me there is still a way to do this?
> Searching keybindings did not yield anything promising either.
> I guess I could read the elisp for the previous emacs and my current
> one, but that is too far over the top for me.  I don't grok elisp
> very well anyway.

Yes, `ESC-2 C-h i' (or `M-2 C-h i') works in Emacs before the Emacs 22 release.
Dunno if this change was intentional or is a bug - you might check the NEWS file
to see. If it was not intentional, then you might want to report a bug using
`M-x report-emacs-bug'.

<<I didn't look.  IMHO, it is definitely a bug.>>

In any case, you can still use `C-u C-h i' to do the same thing - it prompts you
for the Info file to use.

<<This works, but there are not even any hints to get you there.
  In fact, the doc for CTL-u seems to imply that ``CTL-u 2'' is
  equivalent to ``Meta-2'', with some fuzzy words following that
  seem to mean, "well, not quite exactly, but pretty much and you
  need to see each individual command to really know".  Obviously,
  it's not especially clear to me.>>

=================================================================================

If Emacs crashed, <<nope.>>

In GNU Emacs 22.2.1 (x86_64-suse-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2008-09-11 on hammer22
Windowing system distributor `The X.Org Foundation', version 11.0.10400090
configured using `configure  '--with-gcc' '--with-pop' '--without-hesiod' '--with-kerberos' '--with-kerberos5' '--with-leim' '--with-xim' '--with-system-malloc' '--prefix=/usr' '--infodir=/usr/share/info' '--mandir=/usr/share/man' '--localstatedir=/var' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib' '--with-x' '--with-sound' '--with-xpm' '--with-jpeg' '--with-tiff' '--with-gif' '--with-png' '--with-x-toolkit=lucid' '--x-includes=/usr/include' '--x-libraries=/usr/lib64:/usr/share/X11' '--build=x86_64-suse-linux-gnu' 'build_alias=x86_64-suse-linux-gnu' 'CC=gcc' 'CFLAGS=-O2 -fmessage-length=0 -Wall -D_FORTIFY_SOURCE=2 -fstack-protector -g -D_GNU_SOURCE -std=gnu89 -pipe -fno-strict-aliasing -Wno-pointer-sign -Wno-unused-variable -Wno-unused-label -Wno-unprototyped-calls -DSYSTEM_PURESIZE_
 EXTRA=55000 	 -DSITELOAD_PURESIZE_EXTRA=10000 ' 'LDFLAGS=''

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: nil
  locale-coding-system: nil
  default-enable-multibyte-characters: t

Major mode: Fundamental

Minor modes in effect:
  server-mode: t
  show-paren-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-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

Recent input:
<<<not relevant>>>

Recent messages:
<<<also not relevant>>>

bug#1722: Meta-Digit not working for info command

[Drew Adams]

Actually, I should have also mentioned trying `C-h k C-h i', not just reading
NEWS - the help I gave you was only partial. `C-h k C-h i' says this, among
other things:

"In interactive use, a non-numeric prefix argument directs
this command to read a file name from the minibuffer.
A numeric prefix argument selects an Info buffer with the prefix number
appended to the Info buffer name."

That indicates that this change was intentional, and that a numeric prefix arg
(e.g. `M-2') has a new meaning, which is to open Info with a buffer that adds
`2' to the buffer name. To be more precise, it should say that "<N>" is appended
to the buffer name, where N is the numeric prefix-arg value. So, e.g., `M-2'
opens buffer "*info*<2>".

IOW, it's not a bug but a feature. And plain `C-u' continues to give the
behavior you want: prompt for the Info file to use.

You say that there is no hint about this `C-u' behavior, but it is clearly
documented in the doc string of command `info', as shown by `C-h k C-h i' or
`C-h f info'. 

You looked for it in the doc for `C-u'. `C-u' has different behavior for
different keys it precedes, and its doc string cannot (and should not) try to
describe all such particular behaviors. See node `Arguments' of the Emacs
manual.

HTH - Drew

> From: Bruce Korb Sent: Sunday, December 28, 2008 9:18 AM 
> CF: email from help-gnu-emacs
> 
> From: "Drew Adams" To: help-gnu-emacs@gnu.org
> References: <4956B2A5.2050106@gmail.com>
> Subject: RE: How can I select a .info file for info mode?
> Date: Sat, 27 Dec 2008 23:50:51 -0800
> 
> > It used to be the case that ``ESC-2 CTL-h i'' gave me the 
> > opportunity to select the .info file to use for info mode.  Not any more.
> > Plowing through the docs doesn't give me a good enough hint about
> > how to do it either.  Please tell me there is still a way 
> > to do this?
> > Searching keybindings did not yield anything promising either.
> > I guess I could read the elisp for the previous emacs and my current
> > one, but that is too far over the top for me.  I don't grok elisp
> > very well anyway.
> 
> Yes, `ESC-2 C-h i' (or `M-2 C-h i') works in Emacs before the 
> Emacs 22 release. Dunno if this change was intentional or is a bug
> - you might check the NEWS file to see. If it was not intentional,
> then you might want to report a bug using `M-x report-emacs-bug'.
> 
> <<I didn't look.  IMHO, it is definitely a bug.>>
> 
> In any case, you can still use `C-u C-h i' to do the same 
> thing - it prompts you for the Info file to use.
> 
> <<This works, but there are not even any hints to get you there.
>   In fact, the doc for CTL-u seems to imply that ``CTL-u 2'' is
>   equivalent to ``Meta-2'', with some fuzzy words following that
>   seem to mean, "well, not quite exactly, but pretty much and you
>   need to see each individual command to really know".  Obviously,
>   it's not especially clear to me.>>

bug#1722: Meta-Digit not working for info command

[Bruce Korb]

From my perspective, with the additional information, this can be closed.
It's yet another caveat about being changing behavior that folks
have become accustomed to for over a decade.  I've been using emacs for
24 years and re-reading manuals with every release is something I will
most certainly never do.  So, I'd have suggested  ``Esc-2 Ctl-h i''
triggering a prompt:
   OBSOLETE METHOD (use Ctl-u Ctl-h i) -- Info file name:
then I'd have been ready when emacs 23 came out.

Anyway, too late now.  Thank you all for your efforts!

Regards, Bruce