bug#7899: 23.2.91; Unsatisfactory interaction between shell-mode-hook and comint-read-input-ring

[Reuben Thomas]

shell-mode runs comint-read-input-ring. This is in a way unfortunate,
since this means that if you want to change the parameters of
comint-input-ring in shell-mode-hook, then you’re already too late.

I have the following in my .emacs:

(add-hook 'shell-mode-hook
          (lambda ()
            (let ((n (getenv "HISTSIZE")))
              (if n (progn (setq comint-input-ring-size (string-to-number n))
                           (comint-read-input-ring t))))))

This is not appropriate for comint-mode-hook, since HISTSIZE is
shell-specific (really, it’s bash-specific, so I should be testing that
I’m running bash). But now I have to run comint-read-input-ring again.

Perhaps shell-mode should instead append comint-read-input-ring to
shell-mode-hook if it’s not already there, or some such malarky?

There is one further thing that is puzzling me about the situation: I
have quite a large ~/.bash_history (about 200,000 lines). When I ran
shell-mode without first setting comint-input-ring-size correctly, it
was truncated to 500 lines when I killed the shell-mode buffer (as I
would expect). However, after setting comint-input-ring-size to HISTSIZE
(which is 400,000), ~/.bash_history was no longer translated _even
though, as I was not yet running comint-read-input-ring in my shell-mode
hook, only 500 entries were being read_. This seems to contradict the
docstring of comint-write-input-ring, which says that it overwrites
comint-input-ring-file-name if comint-input-ring is non-empty. (However,
it is correct behavior for my shell: I have set shopt histappend. But
this is surely a coincidence, as bash will update the history file
before Emacs, so Emacs should “win”, right?)


In GNU Emacs 23.2.91.4 (i686-pc-linux-gnu, GTK+ Version 2.22.0)
 of 2011-01-13 on canta
Windowing system distributor `The X.Org Foundation', version 11.0.10900000
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_GB.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Shell

Minor modes in effect:
  shell-dirtrack-mode: t
  recentf-mode: t
  show-paren-mode: t
  savehist-mode: t
  minibuffer-electric-default-mode: t
  iswitchb-mode: t
  icomplete-mode: t
  global-whitespace-mode: t
  global-auto-revert-mode: t
  desktop-save-mode: t
  yas/global-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
M-x s h e l l <return> C-h v c o m i n t - i n p u 
t - r i n g <return> M-> M-< M-< C-x k <return> a M-p 
M-p M-p M-p M-p M-p M-p M-p M-p M-p M-p M-n M-n M-n 
M-n M-n M-n M-n M-n M-n M-n M-n M-n M-n M-n M-n M-n 
M-n M-n M-n M-n M-n M-n M-n M-n M-n M-n M-n M-n M-n 
M-n M-n M-n M-n M-n M-n M-n M-n M-n M-n M-n M-n M-n 
M-n M-n M-n M-n M-n M-n M-n <M-backspace> <M-backspace> 
<return> . / M-p M-p M-p M-p M-p M-p M-p M-p M-p M-p 
M-p M-p M-p M-p M-p C-a C-k <return> <return> M-x r 
e p o r t - e m a c s - b u g <return>

Recent messages:
History item: 897
History item: 900
History item: 912
History item: 913
History item: 1202
History item: 1203
History item: 1206
History item: 1399
History item: 1400
History item: 1404

Load-path shadows:
/home/rrt/.emacs.d/elpa/ruby-mode-1.1/ruby-mode hides 
/usr/share/emacs-snapshot/site-lisp/ruby1.8-elisp/ruby-mode
/home/rrt/local/share/emacs/site-lisp/popup hides 
/usr/local/share/emacs/23.2.91/site-lisp/auto-complete/popup
/home/rrt/local/share/emacs/site-lisp/fuzzy hides 
/usr/local/share/emacs/23.2.91/site-lisp/auto-complete/fuzzy
/home/rrt/.emacs.d/elpa/css-mode-1.0/css-mode hides 
/usr/local/share/emacs/23.2.91/site-lisp/css-mode/css-mode
/home/rrt/.emacs.d/elpa/dictionary-1.8.7/link hides 
/usr/local/share/emacs/23.2.91/site-lisp/dictionary-el/link
/home/rrt/.emacs.d/elpa/dictionary-1.8.7/connection hides 
/usr/local/share/emacs/23.2.91/site-lisp/dictionary-el/connection
/home/rrt/.emacs.d/elpa/dictionary-1.8.7/dictionary-init hides 
/usr/local/share/emacs/23.2.91/site-lisp/dictionary-el/dictionary-init
/home/rrt/.emacs.d/elpa/dictionary-1.8.7/dictionary hides 
/usr/local/share/emacs/23.2.91/site-lisp/dictionary-el/dictionary
/home/rrt/.emacs.d/elpa/css-mode-1.0/css-mode hides 
/usr/local/share/emacs/23.2.91/lisp/textmodes/css-mode
/home/rrt/.emacs.d/elpa/ruby-mode-1.1/ruby-mode hides 
/usr/local/share/emacs/23.2.91/lisp/progmodes/ruby-mode
/home/rrt/.emacs.d/elpa/css-mode-1.0/css-mode hides 
/usr/share/emacs/site-lisp/css-mode/css-mode
/usr/local/share/emacs/23.2.91/site-lisp/auctex/tex-info hides 
/usr/share/emacs/site-lisp/auctex/tex-info
/usr/local/share/emacs/23.2.91/site-lisp/auctex/context-nl hides 
/usr/share/emacs/site-lisp/auctex/context-nl
/usr/local/share/emacs/23.2.91/site-lisp/auctex/context-en hides 
/usr/share/emacs/site-lisp/auctex/context-en
/usr/local/share/emacs/23.2.91/site-lisp/auctex/latex hides 
/usr/share/emacs/site-lisp/auctex/latex
/usr/local/share/emacs/23.2.91/site-lisp/auctex/tex-mik hides 
/usr/share/emacs/site-lisp/auctex/tex-mik
/usr/local/share/emacs/23.2.91/site-lisp/dictionary-el/lpath hides 
/usr/share/emacs/site-lisp/auctex/lpath
/usr/local/share/emacs/23.2.91/site-lisp/auctex/tex-buf hides 
/usr/share/emacs/site-lisp/auctex/tex-buf
/usr/local/share/emacs/23.2.91/site-lisp/auctex/tex-jp hides 
/usr/share/emacs/site-lisp/auctex/tex-jp
/usr/local/share/emacs/23.2.91/site-lisp/auctex/tex-bar hides 
/usr/share/emacs/site-lisp/auctex/tex-bar
/usr/local/share/emacs/23.2.91/site-lisp/auctex/tex hides 
/usr/share/emacs/site-lisp/auctex/tex
/usr/local/share/emacs/23.2.91/site-lisp/auctex/multi-prompt hides 
/usr/share/emacs/site-lisp/auctex/multi-prompt
/usr/local/share/emacs/23.2.91/site-lisp/auctex/tex-fptex hides 
/usr/share/emacs/site-lisp/auctex/tex-fptex
/usr/local/share/emacs/23.2.91/site-lisp/auctex/tex-font hides 
/usr/share/emacs/site-lisp/auctex/tex-font
/usr/local/share/emacs/23.2.91/site-lisp/auctex/tex-fold hides 
/usr/share/emacs/site-lisp/auctex/tex-fold
/usr/local/share/emacs/23.2.91/site-lisp/auctex/texmathp hides 
/usr/share/emacs/site-lisp/auctex/texmathp
/usr/local/share/emacs/23.2.91/site-lisp/auctex/context hides 
/usr/share/emacs/site-lisp/auctex/context
/usr/local/share/emacs/23.2.91/site-lisp/auctex/font-latex hides 
/usr/share/emacs/site-lisp/auctex/font-latex
/usr/local/share/emacs/23.2.91/site-lisp/auctex/bib-cite hides 
/usr/share/emacs/site-lisp/auctex/bib-cite
/usr/local/share/emacs/23.2.91/site-lisp/auctex/toolbar-x hides 
/usr/share/emacs/site-lisp/auctex/toolbar-x
/usr/local/share/emacs/23.2.91/site-lisp/auctex/tex-style hides 
/usr/share/emacs/site-lisp/auctex/tex-style

Features:
(shadow sort mail-extr message sendmail ecomplete rfc822 mml mml-sec
password-cache mm-decode mm-bodies mm-encode mailcap mail-parse rfc2231
rfc2047 rfc2045 qp ietf-drums mailabbrev nnheader gnus-util netrc
time-date mm-util mail-prsvr gmm-utils mailheader canlock sha1 hex-util
hashcash mail-utils emacsbug vc-git pp help-mode view ansi-color shell
jka-compr info face-remap filladapt flyspell completing-help recentf
tree-widget wid-edit uniquify paren savehist minibuf-eldef iswitchb
icomplete whitespace autorevert time cus-start cus-load desktop server
php-mode etags cc-langs cc-mode cc-fonts cc-menus cc-cmds cc-styles
cc-align cc-engine cc-vars cc-defs speedbar sb-image ezimage dframe
lua-mode regexp-opt comint ring ropemacs pymacs etags-update
smart-quotes ispell auto-dictionary-autoloads css-mode-autoloads
dictionary-autoloads diff-git-autoloads dired-isearch-autoloads
full-ack-autoloads guess-style-autoloads http-post-simple-autoloads
js2-mode-autoloads magit-autoloads mv-shell-autoloads
ruby-mode-autoloads package reporter advice advice-preload yasnippet
help-fns derived edmacro kmacro easymenu assoc cl cl-19 muse-autoloads
emacs-goodies-el emacs-goodies-custom emacs-goodies-loaddefs easy-mmode
bbdb-autoloads preview-latex tex-site auto-loads tooltip ediff-hook
vc-hooks lisp-float-type mwheel x-win x-dnd font-setting tool-bar dnd
fontset image fringe lisp-mode register page menu-bar rfn-eshadow timer
select scroll-bar mldrag 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 loaddefs button minibuffer faces
cus-face files text-properties overlay md5 base64 format env code-pages
mule custom widget hashtable-print-readable backquote
make-network-process dbusbind system-font-setting font-render-setting
gtk x-toolkit x multi-tty emacs)

-- 
http://rrt.sc3d.org/