bug#61602: 29.0.60; comint-mode redirection

bug#61602: 29.0.60; comint-mode redirection

[Rah Guzar via Bug reports for GNU Emacs, the Swiss army knife of text editors]

Dear Emacs maintainers,
   I have been working on a major mode derived from comint-mode. The mode
   uses redirection to show documentation in a separate buffer. Sometimes,
   a prompt would appear in the output of the command producing the
   documentation and this would end the redirection prematurely. Searching
   among variables in comint-mode I found comint-redirect-finished-regexp
   and its docstring made me believe that I could set it to change the end
   of redirection. However setting it had a no effect and looking at the
   sources I found that this is because it is set by comint-redirect-setup
   and comint-redirect-send-command-to-process calls comint-redirect-setup
   so that it is always set to comint-prompt-regexp during redirection.

   This is confusing behavior because docstring of
   comint-redirect-finished-regexp gives no clue that setting it will have
   no effect. Similarly the docstring of comint-prompt-regexp states that
   its value is only used when comint-use-prompt-regexp is non-nil but
   that is not true for redirection.

   Overall I think it would be nice to have an optional argument to
   comint-redirect-send-command-to-process which allows a user to
   explicitly pass the regexp to use for ending redirection.

   Another issue I had was that I wanted to run some commands when
   redirection ended. There didn't seem to be any hooks that accomplished
   this but from source of comint-redirect-preoutput-filter I found that
   comint-redirect-hook is run when redirection finishes. However
   comint-redirect-hook is not defined as a variable and nothing seems to
   give any hint of its existence.

Thanks,
Rahguzar


In GNU Emacs 29.0.60 (build 1, x86_64-suse-linux-gnu, GTK+ Version
 3.24.35, cairo version 1.17.6) of 2023-02-17 built on build79
System Description: openSUSE Tumbleweed

Configured using:
 'configure --host=x86_64-suse-linux-gnu --build=x86_64-suse-linux-gnu
 --program-prefix= --disable-dependency-tracking --prefix=/usr
 --exec-prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin
 --sysconfdir=/etc --datadir=/usr/share --includedir=/usr/include
 --libdir=/usr/lib64 --libexecdir=/usr/libexec --localstatedir=/var
 --sharedstatedir=/var/lib --mandir=/usr/share/man
 --infodir=/usr/share/info --with-pgtk --with-native-compilation=aot
 --with-cairo --with-libotf --with-jpeg --with-tiff --with-gif
 --with-png --with-rsvg --with-xft --with-xml2 --with-dbus --with-sound
 --with-json --with-mailutils --with-gnutls --with-tree-sitter
 --enable-locallisppath=/usr/share/emacs/29.0.60/site-lisp:/usr/share/emacs/site-lisp
 'CFLAGS=-O2 -Wall -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3
 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables
 -fstack-clash-protection -Werror=return-type -flto=auto'
 LDFLAGS=-Wl,-O2'

Configured features:
CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GSETTINGS HARFBUZZ JPEG JSON
LIBOTF LIBSELINUX LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY
PDUMPER PGTK PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF
TOOLKIT_SCROLL_BARS TREE_SITTER XIM GTK3 ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: mu4e-headers

Minor modes in effect:
  delete-selection-mode: t
  projectile-mode: t
  recentf-mode: t
  save-place-mode: t
  global-so-long-mode: t
  which-key-mode: t
  savehist-mode: t
  better-jumper-mode: t
  better-jumper-local-mode: t
  global-company-mode: t
  company-mode: t
  vertico-mode: t
  all-the-icons-completion-mode: t
  marginalia-mode: t
  evil-goggles-mode: t
  evil-escape-mode: t
  evil-snipe-override-mode: t
  evil-snipe-mode: t
  gcmh-mode: t
  winner-mode: t
  smartparens-global-mode: t
  ws-butler-global-mode: t
  global-undo-fu-session-mode: t
  undo-fu-mode: t
  workroom-mode: t
  mu4e-search-minor-mode: t
  global-hl-line-mode: t
  hl-line-mode: t
  mu4e-update-minor-mode: t
  mu4e-context-minor-mode: t
  dirvish-override-dired-mode: t
  server-mode: t
  solaire-global-mode: t
  solaire-mode: t
  shell-dirtrack-mode: t
  evil-mode: t
  evil-local-mode: t
  windmove-mode: t
  +popup-mode: t
  +modeline-global-mode: t
  +modeline-mode: t
  override-global-mode: t
  general-override-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  show-paren-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  window-divider-mode: t
  buffer-read-only: t
  size-indication-mode: t
  line-number-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  abbrev-mode: t

Load-path shadows:
/home/azeem/.emacs.d/.local/straight/build-29.0.60/citar-embark/citar-embark hides /home/azeem/.emacs.d/.local/straight/build-29.0.60/citar/citar-embark

Features:
(shadow disp-table whitespace delsel display-line-numbers adaptive-wrap
spell-fu ispell auto-minor-mode projectile lisp-mnt evil-collection-grep
grep ibuf-ext evil-collection-ibuffer ibuffer ibuffer-loaddefs recentf
tree-widget saveplace evil-collection-so-long so-long emacsbug sort
gnus-cite smiley shr-color mm-archive mail-extr textsec uni-scripts
idna-mapping ucs-normalize uni-confusable textsec-check qp cursor-sensor
vertico-repeat evil-collection-which-key which-key savehist
better-jumper company-capf company evil-collection-vertico vertico
orderless all-the-icons-completion marginalia evil-goggles pulse color
evil-easymotion evil-escape evil-snipe autorevert filenotify gcmh winner
smartparens-config smartparens-text smartparens dash ws-butler
undo-fu-session undo-fu workroom compat desktop frameset
evil-collection-mu4e mu4e mu4e-org evil-collection-org smartparens-org
org ob ob-tangle ob-ref ob-lob ob-table ob-exp org-macro org-src
ob-comint org-pcomplete org-list org-footnote org-faces org-entities
noutline outline ob-emacs-lisp org-table ol org-keys oc-natbib oc-csl
bibtex oc-biblatex oc org-loaddefs find-func mu4e-main mu4e-view
gnus-art mm-uu mml2015 mm-view mml-smime smime gnutls dig gnus-sum
gnus-group gnus-undo gnus-start gnus-dbus dbus gnus-cloud nnimap nnmail
mail-source utf7 nnoo parse-time iso8601 gnus-spec gnus-int gnus-range
gnus-win evil-collection-gnus gnus nnheader range
evil-collection-calendar cal-menu calendar cal-loaddefs mu4e-headers
mu4e-compose mu4e-draft mu4e-actions smtpmail mu4e-search mu4e-lists
mu4e-bookmarks mu4e-mark mu4e-message shr pixel-fill kinsoku url-file
svg xml dom browse-url url url-proxy url-privacy url-expand url-methods
url-history url-cookie generate-lisp-file url-domsuf url-util url-parse
auth-source json map url-vars flow-fill mule-util hl-line mu4e-contacts
mu4e-update mu4e-folders mu4e-server mu4e-context mu4e-vars mu4e-helpers
mu4e-config evil-collection-bookmark bookmark ido message sendmail
mailcap yank-media puny dirvish transient eieio eieio-core
evil-collection-dired dired dired-loaddefs rfc822 mml mml-sec
password-cache evil-collection-epa epa epg rfc6068 epg-config gnus-util
time-date mm-decode mm-bodies mm-encode mail-parse rfc2231 rfc2047
rfc2045 mm-util ietf-drums mail-prsvr mailabbrev mail-utils gmm-utils
mailheader server dtrt-indent doom-themes-ext-org solaire-mode
face-remap doom-earl-grey-theme doom-themes doom-themes-base midnight
evil-collection-flymake flymake-proc flymake project
evil-collection-compile evil-collection-custom cus-edit cus-load
wid-edit evil-collection-comint evil-collection annalist compile
text-property-search html2text ob-core org-cycle org-fold org-fold-core
org-compat ob-eval org-version org-macs format-spec ibuf-macs evil
evil-integration evil-maps evil-commands reveal flyspell evil-jumps
evil-command-window evil-search shell pcomplete comint ansi-osc
ansi-color evil-types evil-macros evil-repeat evil-states evil-core comp
comp-cstr warnings icons byte-opt advice evil-common windmove calc
calc-loaddefs calc-macs thingatpt rect evil-digraphs evil-vars ring
all-the-icons all-the-icons-faces data-material data-weathericons
data-octicons data-fileicons data-faicons data-alltheicons let-alist
derived edmacro kmacro use-package-bind-key bind-key rx doom-editor
doom-projects doom-ui easy-mmode doom-keybinds pp cl-extra help-mode
use-package-core bytecomp byte-compile general tex-site doom-start
doom-modules cl-seq doom doom-lib cl-macs cl-loaddefs cl-lib pcase gv
jansson dynamic-modules subr-x rmc iso-transl tooltip cconv eldoc paren
electric uniquify ediff-hook vc-hooks lisp-float-type mwheel
term/pgtk-win pgtk-win term/common-win pgtk-dnd tool-bar dnd fontset
image regexp-opt fringe tabulated-list replace newcomment text-mode
lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow isearch
easymenu timer select scroll-bar mouse jit-lock font-lock syntax
font-core term/tty-colors frame minibuffer nadvice seq simple cl-generic
indonesian philippine cham georgian utf-8-lang misc-lang vietnamese
tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek
romanian slovak czech european ethiopic indian cyrillic chinese
composite emoji-zwj charscript charprop case-table epa-hook
jka-cmpr-hook help abbrev obarray oclosure cl-preloaded button loaddefs
theme-loaddefs faces cus-face macroexp files window text-properties
overlay sha1 md5 base64 format env code-pages mule custom widget keymap
hashtable-print-readable backquote threads dbusbind inotify
dynamic-setting system-font-setting font-render-setting cairo gtk pgtk
multi-tty make-network-process native-compile emacs)

Memory information:
((conses 16 944541 309286)
 (symbols 48 41240 1)
 (strings 32 291783 19116)
 (string-bytes 1 6577740)
 (vectors 16 85429)
 (vector-slots 8 2190100 207157)
 (floats 8 1276 1590)
 (intervals 56 12251 9085)
 (buffers 984 21))

bug#61602: 29.0.60; comint-mode redirection

[Rah Guzar via Bug reports for GNU Emacs, the Swiss army knife of text editors]

[-- Attachment #1: Type: text/plain, Size: 10623 bytes --]

Dear Emacs maintainers,
  Please find attached a patch that addresses these points. If desired I
  can also separate out the documentation changes which I think are more
  important from the code changes. I think even code changes are trivial
  and safe. Please let me know if any changes are required.

  I have not yet signed the copyright assignment but I am in the process
  of doing it. I think this change falls within the 15 lines exemption
  although it saturates it.

Thanks,
Rah Guzar

Rah Guzar <rahguzar@zohomail.eu> writes:

> Dear Emacs maintainers,
>    I have been working on a major mode derived from comint-mode. The mode
>    uses redirection to show documentation in a separate buffer. Sometimes,
>    a prompt would appear in the output of the command producing the
>    documentation and this would end the redirection prematurely. Searching
>    among variables in comint-mode I found comint-redirect-finished-regexp
>    and its docstring made me believe that I could set it to change the end
>    of redirection. However setting it had a no effect and looking at the
>    sources I found that this is because it is set by comint-redirect-setup
>    and comint-redirect-send-command-to-process calls comint-redirect-setup
>    so that it is always set to comint-prompt-regexp during redirection.
>
>    This is confusing behavior because docstring of
>    comint-redirect-finished-regexp gives no clue that setting it will have
>    no effect. Similarly the docstring of comint-prompt-regexp states that
>    its value is only used when comint-use-prompt-regexp is non-nil but
>    that is not true for redirection.
>
>    Overall I think it would be nice to have an optional argument to
>    comint-redirect-send-command-to-process which allows a user to
>    explicitly pass the regexp to use for ending redirection.
>
>    Another issue I had was that I wanted to run some commands when
>    redirection ended. There didn't seem to be any hooks that accomplished
>    this but from source of comint-redirect-preoutput-filter I found that
>    comint-redirect-hook is run when redirection finishes. However
>    comint-redirect-hook is not defined as a variable and nothing seems to
>    give any hint of its existence.
>
> Thanks,
> Rahguzar
>
>
> In GNU Emacs 29.0.60 (build 1, x86_64-suse-linux-gnu, GTK+ Version
>  3.24.35, cairo version 1.17.6) of 2023-02-17 built on build79
> System Description: openSUSE Tumbleweed
>
> Configured using:
>  'configure --host=x86_64-suse-linux-gnu --build=x86_64-suse-linux-gnu
>  --program-prefix= --disable-dependency-tracking --prefix=/usr
>  --exec-prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin
>  --sysconfdir=/etc --datadir=/usr/share --includedir=/usr/include
>  --libdir=/usr/lib64 --libexecdir=/usr/libexec --localstatedir=/var
>  --sharedstatedir=/var/lib --mandir=/usr/share/man
>  --infodir=/usr/share/info --with-pgtk --with-native-compilation=aot
>  --with-cairo --with-libotf --with-jpeg --with-tiff --with-gif
>  --with-png --with-rsvg --with-xft --with-xml2 --with-dbus --with-sound
>  --with-json --with-mailutils --with-gnutls --with-tree-sitter
>  --enable-locallisppath=/usr/share/emacs/29.0.60/site-lisp:/usr/share/emacs/site-lisp
>  'CFLAGS=-O2 -Wall -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=3
>  -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables
>  -fstack-clash-protection -Werror=return-type -flto=auto'
>  LDFLAGS=-Wl,-O2'
>
> Configured features:
> CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GSETTINGS HARFBUZZ JPEG JSON
> LIBOTF LIBSELINUX LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY
> PDUMPER PGTK PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF
> TOOLKIT_SCROLL_BARS TREE_SITTER XIM GTK3 ZLIB
>
> Important settings:
>   value of $LANG: en_US.UTF-8
>   locale-coding-system: utf-8-unix
>
> Major mode: mu4e-headers
>
> Minor modes in effect:
>   delete-selection-mode: t
>   projectile-mode: t
>   recentf-mode: t
>   save-place-mode: t
>   global-so-long-mode: t
>   which-key-mode: t
>   savehist-mode: t
>   better-jumper-mode: t
>   better-jumper-local-mode: t
>   global-company-mode: t
>   company-mode: t
>   vertico-mode: t
>   all-the-icons-completion-mode: t
>   marginalia-mode: t
>   evil-goggles-mode: t
>   evil-escape-mode: t
>   evil-snipe-override-mode: t
>   evil-snipe-mode: t
>   gcmh-mode: t
>   winner-mode: t
>   smartparens-global-mode: t
>   ws-butler-global-mode: t
>   global-undo-fu-session-mode: t
>   undo-fu-mode: t
>   workroom-mode: t
>   mu4e-search-minor-mode: t
>   global-hl-line-mode: t
>   hl-line-mode: t
>   mu4e-update-minor-mode: t
>   mu4e-context-minor-mode: t
>   dirvish-override-dired-mode: t
>   server-mode: t
>   solaire-global-mode: t
>   solaire-mode: t
>   shell-dirtrack-mode: t
>   evil-mode: t
>   evil-local-mode: t
>   windmove-mode: t
>   +popup-mode: t
>   +modeline-global-mode: t
>   +modeline-mode: t
>   override-global-mode: t
>   general-override-mode: t
>   global-eldoc-mode: t
>   eldoc-mode: t
>   show-paren-mode: t
>   electric-indent-mode: t
>   mouse-wheel-mode: t
>   file-name-shadow-mode: t
>   global-font-lock-mode: t
>   font-lock-mode: t
>   window-divider-mode: t
>   buffer-read-only: t
>   size-indication-mode: t
>   line-number-mode: t
>   transient-mark-mode: t
>   auto-composition-mode: t
>   auto-encryption-mode: t
>   auto-compression-mode: t
>   abbrev-mode: t
>
> Load-path shadows:
> /home/azeem/.emacs.d/.local/straight/build-29.0.60/citar-embark/citar-embark hides /home/azeem/.emacs.d/.local/straight/build-29.0.60/citar/citar-embark
>
> Features:
> (shadow disp-table whitespace delsel display-line-numbers adaptive-wrap
> spell-fu ispell auto-minor-mode projectile lisp-mnt evil-collection-grep
> grep ibuf-ext evil-collection-ibuffer ibuffer ibuffer-loaddefs recentf
> tree-widget saveplace evil-collection-so-long so-long emacsbug sort
> gnus-cite smiley shr-color mm-archive mail-extr textsec uni-scripts
> idna-mapping ucs-normalize uni-confusable textsec-check qp cursor-sensor
> vertico-repeat evil-collection-which-key which-key savehist
> better-jumper company-capf company evil-collection-vertico vertico
> orderless all-the-icons-completion marginalia evil-goggles pulse color
> evil-easymotion evil-escape evil-snipe autorevert filenotify gcmh winner
> smartparens-config smartparens-text smartparens dash ws-butler
> undo-fu-session undo-fu workroom compat desktop frameset
> evil-collection-mu4e mu4e mu4e-org evil-collection-org smartparens-org
> org ob ob-tangle ob-ref ob-lob ob-table ob-exp org-macro org-src
> ob-comint org-pcomplete org-list org-footnote org-faces org-entities
> noutline outline ob-emacs-lisp org-table ol org-keys oc-natbib oc-csl
> bibtex oc-biblatex oc org-loaddefs find-func mu4e-main mu4e-view
> gnus-art mm-uu mml2015 mm-view mml-smime smime gnutls dig gnus-sum
> gnus-group gnus-undo gnus-start gnus-dbus dbus gnus-cloud nnimap nnmail
> mail-source utf7 nnoo parse-time iso8601 gnus-spec gnus-int gnus-range
> gnus-win evil-collection-gnus gnus nnheader range
> evil-collection-calendar cal-menu calendar cal-loaddefs mu4e-headers
> mu4e-compose mu4e-draft mu4e-actions smtpmail mu4e-search mu4e-lists
> mu4e-bookmarks mu4e-mark mu4e-message shr pixel-fill kinsoku url-file
> svg xml dom browse-url url url-proxy url-privacy url-expand url-methods
> url-history url-cookie generate-lisp-file url-domsuf url-util url-parse
> auth-source json map url-vars flow-fill mule-util hl-line mu4e-contacts
> mu4e-update mu4e-folders mu4e-server mu4e-context mu4e-vars mu4e-helpers
> mu4e-config evil-collection-bookmark bookmark ido message sendmail
> mailcap yank-media puny dirvish transient eieio eieio-core
> evil-collection-dired dired dired-loaddefs rfc822 mml mml-sec
> password-cache evil-collection-epa epa epg rfc6068 epg-config gnus-util
> time-date mm-decode mm-bodies mm-encode mail-parse rfc2231 rfc2047
> rfc2045 mm-util ietf-drums mail-prsvr mailabbrev mail-utils gmm-utils
> mailheader server dtrt-indent doom-themes-ext-org solaire-mode
> face-remap doom-earl-grey-theme doom-themes doom-themes-base midnight
> evil-collection-flymake flymake-proc flymake project
> evil-collection-compile evil-collection-custom cus-edit cus-load
> wid-edit evil-collection-comint evil-collection annalist compile
> text-property-search html2text ob-core org-cycle org-fold org-fold-core
> org-compat ob-eval org-version org-macs format-spec ibuf-macs evil
> evil-integration evil-maps evil-commands reveal flyspell evil-jumps
> evil-command-window evil-search shell pcomplete comint ansi-osc
> ansi-color evil-types evil-macros evil-repeat evil-states evil-core comp
> comp-cstr warnings icons byte-opt advice evil-common windmove calc
> calc-loaddefs calc-macs thingatpt rect evil-digraphs evil-vars ring
> all-the-icons all-the-icons-faces data-material data-weathericons
> data-octicons data-fileicons data-faicons data-alltheicons let-alist
> derived edmacro kmacro use-package-bind-key bind-key rx doom-editor
> doom-projects doom-ui easy-mmode doom-keybinds pp cl-extra help-mode
> use-package-core bytecomp byte-compile general tex-site doom-start
> doom-modules cl-seq doom doom-lib cl-macs cl-loaddefs cl-lib pcase gv
> jansson dynamic-modules subr-x rmc iso-transl tooltip cconv eldoc paren
> electric uniquify ediff-hook vc-hooks lisp-float-type mwheel
> term/pgtk-win pgtk-win term/common-win pgtk-dnd tool-bar dnd fontset
> image regexp-opt fringe tabulated-list replace newcomment text-mode
> lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow isearch
> easymenu timer select scroll-bar mouse jit-lock font-lock syntax
> font-core term/tty-colors frame minibuffer nadvice seq simple cl-generic
> indonesian philippine cham georgian utf-8-lang misc-lang vietnamese
> tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek
> romanian slovak czech european ethiopic indian cyrillic chinese
> composite emoji-zwj charscript charprop case-table epa-hook
> jka-cmpr-hook help abbrev obarray oclosure cl-preloaded button loaddefs
> theme-loaddefs faces cus-face macroexp files window text-properties
> overlay sha1 md5 base64 format env code-pages mule custom widget keymap
> hashtable-print-readable backquote threads dbusbind inotify
> dynamic-setting system-font-setting font-render-setting cairo gtk pgtk
> multi-tty make-network-process native-compile emacs)
>
> Memory information:
> ((conses 16 944541 309286)
>  (symbols 48 41240 1)
>  (strings 32 291783 19116)
>  (string-bytes 1 6577740)
>  (vectors 16 85429)
>  (vector-slots 8 2190100 207157)
>  (floats 8 1276 1590)
>  (intervals 56 12251 9085)
>  (buffers 984 21))


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: comint-redirect.patch --]
[-- Type: text/x-patch, Size: 2413 bytes --]

diff --git a/lisp/comint.el b/lisp/comint.el
index 682b555a33c..98f4d315d64 100644
--- a/lisp/comint.el
+++ b/lisp/comint.el
@@ -161,7 +161,10 @@ comint-prompt-regexp
 Defaults to \"^\", the null string at BOL.
 
 This variable is only used if the variable
-`comint-use-prompt-regexp' is non-nil.
+`comint-use-prompt-regexp' is non-nil.  The exception to
+this is redirection.  Many commands including
+`comint-redirect-send-command-to-process' use it as
+`comint-redirect-finished-regexp'.
 
 Good choices:
   Canonical Lisp: \"^[^> \\n]*>+:? *\" (Lucid, franz, kcl, T, cscheme, oaklisp)
@@ -3637,7 +3640,12 @@ comint-redirect-output-buffer
 (defvar comint-redirect-finished-regexp nil
   "Regular expression that determines when to stop redirection in Comint.
 When the redirection filter function is given output that matches this regexp,
-the output is inserted as usual, and redirection is completed.")
+the output is inserted as usual, and redirection is completed.
+This is an internal variable set by `comint-redirect-setup' and setting it
+directly has no effect.")
+
+(defvar comint-redirect-hook nil
+  "Hook run when a redirection finishes.")
 
 (defvar comint-redirect-insert-matching-regexp nil
   "If non-nil, the text that ends a redirection is included in it.
@@ -3833,11 +3841,13 @@ comint-redirect-send-command
 
 ;;;###autoload
 (defun comint-redirect-send-command-to-process
-  (command output-buffer process echo &optional no-display)
+  (command output-buffer process echo &optional no-display finished-regexp)
   "Send COMMAND to PROCESS, with output to OUTPUT-BUFFER.
 With prefix arg, echo output in process buffer.
 
-If NO-DISPLAY is non-nil, do not show the output buffer."
+If NO-DISPLAY is non-nil, do not show the output buffer.
+If FINISHED-REGEXP is non-nil it is used as `comint-redirect-finished-regexp'
+instead of `comint-prompt-regexp'."
   (interactive "sCommand: \nBOutput Buffer: \nbProcess Buffer: \nP")
   (let* (;; The process buffer
 	 (process-buffer (if (processp process)
@@ -3858,7 +3868,7 @@ comint-redirect-send-command-to-process
       (comint-redirect-setup
        output-buffer
        (current-buffer)                 ; Comint Buffer
-       comint-prompt-regexp             ; Finished Regexp
+       (or finished-regexp comint-prompt-regexp)             ; Finished Regexp
        echo)                            ; Echo input
 
       ;; Set the filter.

bug#61602: [PATCH]: comint-mode redirection

[Rah Guzar via Bug reports for GNU Emacs, the Swiss army knife of text editors]

[-- Attachment #1: Type: text/plain, Size: 373 bytes --]

Dear Emacs Maintainers,
   A while back I sent a patch that addresses the points in this bug report. I have since received the confirmation that I have completed the copyright paperwork, so I am bringing it to your attention again. This is my first time contributing so please let me know if I should do somethings differently or if changes are needed.

Thanks,
Rah Guzar


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: comint-redirect.patch --]
[-- Type: text/x-patch, Size: 2413 bytes --]

diff --git a/lisp/comint.el b/lisp/comint.el
index 682b555a33c..98f4d315d64 100644
--- a/lisp/comint.el
+++ b/lisp/comint.el
@@ -161,7 +161,10 @@ comint-prompt-regexp
 Defaults to \"^\", the null string at BOL.
 
 This variable is only used if the variable
-`comint-use-prompt-regexp' is non-nil.
+`comint-use-prompt-regexp' is non-nil.  The exception to
+this is redirection.  Many commands including
+`comint-redirect-send-command-to-process' use it as
+`comint-redirect-finished-regexp'.
 
 Good choices:
   Canonical Lisp: \"^[^> \\n]*>+:? *\" (Lucid, franz, kcl, T, cscheme, oaklisp)
@@ -3637,7 +3640,12 @@ comint-redirect-output-buffer
 (defvar comint-redirect-finished-regexp nil
   "Regular expression that determines when to stop redirection in Comint.
 When the redirection filter function is given output that matches this regexp,
-the output is inserted as usual, and redirection is completed.")
+the output is inserted as usual, and redirection is completed.
+This is an internal variable set by `comint-redirect-setup' and setting it
+directly has no effect.")
+
+(defvar comint-redirect-hook nil
+  "Hook run when a redirection finishes.")
 
 (defvar comint-redirect-insert-matching-regexp nil
   "If non-nil, the text that ends a redirection is included in it.
@@ -3833,11 +3841,13 @@ comint-redirect-send-command
 
 ;;;###autoload
 (defun comint-redirect-send-command-to-process
-  (command output-buffer process echo &optional no-display)
+  (command output-buffer process echo &optional no-display finished-regexp)
   "Send COMMAND to PROCESS, with output to OUTPUT-BUFFER.
 With prefix arg, echo output in process buffer.
 
-If NO-DISPLAY is non-nil, do not show the output buffer."
+If NO-DISPLAY is non-nil, do not show the output buffer.
+If FINISHED-REGEXP is non-nil it is used as `comint-redirect-finished-regexp'
+instead of `comint-prompt-regexp'."
   (interactive "sCommand: \nBOutput Buffer: \nbProcess Buffer: \nP")
   (let* (;; The process buffer
 	 (process-buffer (if (processp process)
@@ -3858,7 +3868,7 @@ comint-redirect-send-command-to-process
       (comint-redirect-setup
        output-buffer
        (current-buffer)                 ; Comint Buffer
-       comint-prompt-regexp             ; Finished Regexp
+       (or finished-regexp comint-prompt-regexp)             ; Finished Regexp
        echo)                            ; Echo input
 
       ;; Set the filter.

bug#61602: [PATCH]: comint-mode redirection

[Eli Zaretskii]

> Date: Thu, 11 May 2023 19:45:09 +0200
> From:  Rah Guzar via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> Dear Emacs Maintainers,
>    A while back I sent a patch that addresses the points in this bug report. I have since received the confirmation that I have completed the copyright paperwork, so I am bringing it to your attention again. This is my first time contributing so please let me know if I should do somethings differently or if changes are needed.

Thanks, but your paperwork is not yet complete.  So please wait a bit
longer.

bug#61602: [PATCH]: comint-mode redirection

[Rah Guzar via Bug reports for GNU Emacs, the Swiss army knife of text editors]

Hi Eli,
  On May 4th, I received an email from Craigh Topham including text,

> Hello,

> Your assignment/disclaimer process with the FSF is currently
> complete; your fully executed PDF will be sent to you in a separate
> email immediately following this one.

> Please remember to let us know when your employment status changes, as
> this may affect your assignment status.

> Thank you for your contribution!

and I also received the email with the pdf.

So I assumed the paperwork was complete.

Eli Zaretskii <eliz@gnu.org> writes:

>> Date: Thu, 11 May 2023 19:45:09 +0200
>> From:  Rah Guzar via "Bug reports for GNU Emacs,
>>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
>>
>> Dear Emacs Maintainers,
>>    A while back I sent a patch that addresses the points in this bug report. I have since received the confirmation that I have completed the copyright paperwork, so I am bringing it to your attention again. This is my first time contributing so please let me know if I should do somethings differently or if changes are needed.
>
> Thanks, but your paperwork is not yet complete.  So please wait a bit
> longer.

bug#61602: [PATCH]: comint-mode redirection

[Ruijie Yu via Bug reports for GNU Emacs, the Swiss army knife of text editors]

Thanks for the patch.  First of all, when sending a patch(set) for
Emacs, you need to run something like this:

    $ git format-patch

and send the generated file(s).  Take a look at its manpage and ask if
you have any questions.  What you have sent is a "diff" file, which
bears no commit messages.  At least in Emacs contributions, patches
should usually come together with their commit messages.

And there are guidelines on commit messages, see /CONTRIBUTE on
emacs.git.

Further in-line comments below.

Rah Guzar via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org> writes:

> Dear Emacs Maintainers,
>    A while back I sent a patch that addresses the points in this bug report. I
> have since received the confirmation that I have completed the copyright
> paperwork, so I am bringing it to your attention again. This is my first time
> contributing so please let me know if I should do somethings differently or if
> changes are needed.
>
> Thanks,
> Rah Guzar
>
> [2. text/x-patch; comint-redirect.patch]...

> diff --git a/lisp/comint.el b/lisp/comint.el
> index 682b555a33c..98f4d315d64 100644
> --- a/lisp/comint.el
> +++ b/lisp/comint.el
> @@ -161,7 +161,10 @@ comint-prompt-regexp
>  Defaults to \"^\", the null string at BOL.
>  
>  This variable is only used if the variable
> -`comint-use-prompt-regexp' is non-nil.
> +`comint-use-prompt-regexp' is non-nil.  The exception to
> +this is redirection.  Many commands including
> +`comint-redirect-send-command-to-process' use it as
> +`comint-redirect-finished-regexp'.

This paragraph sounds a bit weird, but I don't know how to reword it.
Maybe someone else can help.

>  Good choices:
>    Canonical Lisp: \"^[^> \\n]*>+:? *\" (Lucid, franz, kcl, T, cscheme, oaklisp)
> @@ -3637,7 +3640,12 @@ comint-redirect-output-buffer
>  (defvar comint-redirect-finished-regexp nil
>    "Regular expression that determines when to stop redirection in Comint.
>  When the redirection filter function is given output that matches this regexp,
> -the output is inserted as usual, and redirection is completed.")
> +the output is inserted as usual, and redirection is completed.
> +This is an internal variable set by `comint-redirect-setup' and setting it
> +directly has no effect.")

If this is indeed a private variable, why does it contain no
double-dashes in its name prior to your changes?

Also, here and elsewhere, except for the first line, there should
generally be one empty line between paragraphs.

> +
> +(defvar comint-redirect-hook nil
> +  "Hook run when a redirection finishes.")

Does it make sense for a user to customize the hook?  If so, you should
convert this variable into a `defcustom'.

>  (defvar comint-redirect-insert-matching-regexp nil
>    "If non-nil, the text that ends a redirection is included in it.
> @@ -3833,11 +3841,13 @@ comint-redirect-send-command
>  
>  ;;;###autoload
>  (defun comint-redirect-send-command-to-process
> -  (command output-buffer process echo &optional no-display)
> +  (command output-buffer process echo &optional no-display finished-regexp)
>    "Send COMMAND to PROCESS, with output to OUTPUT-BUFFER.
>  With prefix arg, echo output in process buffer.
>  
> -If NO-DISPLAY is non-nil, do not show the output buffer."
> +If NO-DISPLAY is non-nil, do not show the output buffer.
> +If FINISHED-REGEXP is non-nil it is used as `comint-redirect-finished-regexp'
> +instead of `comint-prompt-regexp'."

Please clarify what "it" is.

If you are referring to the change below from `cominit-prompt-regexp' to
`(or finished-regexp comint-prompt-regexp)', then the current form is
ambiguous, and maybe you should say something like this:

    If F-R is non-nil, it is used as `c-r-f-r'.  Otherwise `c-p-r' is
    used as `c-r-f-r'.

>    (interactive "sCommand: \nBOutput Buffer: \nbProcess Buffer: \nP")
>    (let* (;; The process buffer
>  	 (process-buffer (if (processp process)
> @@ -3858,7 +3868,7 @@ comint-redirect-send-command-to-process
>        (comint-redirect-setup
>         output-buffer
>         (current-buffer)                 ; Comint Buffer
> -       comint-prompt-regexp             ; Finished Regexp
> +       (or finished-regexp comint-prompt-regexp)             ; Finished Regexp
>         echo)                            ; Echo input
>  
>        ;; Set the filter.

-- 
Best,


RY

bug#61602: [PATCH]: comint-mode redirection

[Eli Zaretskii]

> From: Rah Guzar <rahguzar@zohomail.eu>
> Cc: 61602@debbugs.gnu.org
> Date: Thu, 11 May 2023 20:35:46 +0200
> 
> Hi Eli,
>   On May 4th, I received an email from Craigh Topham including text,
> 
> > Hello,
> 
> > Your assignment/disclaimer process with the FSF is currently
> > complete; your fully executed PDF will be sent to you in a separate
> > email immediately following this one.
> 
> > Please remember to let us know when your employment status changes, as
> > this may affect your assignment status.
> 
> > Thank you for your contribution!
> 
> and I also received the email with the pdf.
> 
> So I assumed the paperwork was complete.

I usually wait until the assignment is "officially" on file.  It is
there as of this morning, so we can accept your contributions.

Thanks.

bug#61602: [PATCH]: comint-mode redirection

[Eli Zaretskii]

> Cc: 61602@debbugs.gnu.org
> Date: Fri, 12 May 2023 10:16:48 +0800
> From:  Ruijie Yu via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> 
> Thanks for the patch.  First of all, when sending a patch(set) for
> Emacs, you need to run something like this:
> 
>     $ git format-patch
> 
> and send the generated file(s).

No, this is not a requirement around here.  We prefer format-patch,
indeed, but we don't enforce it.  Simple diffs are perfectly
acceptable.

> What you have sent is a "diff" file, which bears no commit messages.
> At least in Emacs contributions, patches should usually come
> together with their commit messages.

That is true.  But adding commit log messages doesn't have to be via
"git format-patch".

> > --- a/lisp/comint.el
> > +++ b/lisp/comint.el
> > @@ -161,7 +161,10 @@ comint-prompt-regexp
> >  Defaults to \"^\", the null string at BOL.
> >  
> >  This variable is only used if the variable
> > -`comint-use-prompt-regexp' is non-nil.
> > +`comint-use-prompt-regexp' is non-nil.  The exception to
> > +this is redirection.  Many commands including
> > +`comint-redirect-send-command-to-process' use it as
> > +`comint-redirect-finished-regexp'.
> 
> This paragraph sounds a bit weird, but I don't know how to reword it.
> Maybe someone else can help.

I'm not sure the addition is necessary in the first place.  What is
its purpose? why is it useful to mention those exceptional cases?

> Also, here and elsewhere, except for the first line, there should
> generally be one empty line between paragraphs.

This is not a requirement.  It's a judgment call whether an empty line
is needed or not.

> > -If NO-DISPLAY is non-nil, do not show the output buffer."
> > +If NO-DISPLAY is non-nil, do not show the output buffer.
> > +If FINISHED-REGEXP is non-nil it is used as `comint-redirect-finished-regexp'
> > +instead of `comint-prompt-regexp'."
> 
> Please clarify what "it" is.

I think it's clear in this case: there's no other candidate for being
"it" here except FINISHED-REGEXP.

bug#61602: [PATCH]: comint-mode redirection

[Ruijie Yu via Bug reports for GNU Emacs, the Swiss army knife of text editors]

Eli Zaretskii <eliz@gnu.org> writes:

>> Cc: 61602@debbugs.gnu.org
>> Date: Fri, 12 May 2023 10:16:48 +0800
>> From:  Ruijie Yu via "Bug reports for GNU Emacs,
>>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
>> 
>> 
>> Thanks for the patch.  First of all, when sending a patch(set) for
>> Emacs, you need to run something like this:
>> 
>>     $ git format-patch
>> 
>> and send the generated file(s).
>
> No, this is not a requirement around here.  We prefer format-patch,
> indeed, but we don't enforce it.  Simple diffs are perfectly
> acceptable.

Yes, I should have worded that way.  I meant exactly what you said: it
is a preferred way but not a requirement.

>> What you have sent is a "diff" file, which bears no commit messages.
>> At least in Emacs contributions, patches should usually come
>> together with their commit messages.
>
> That is true.  But adding commit log messages doesn't have to be via
> "git format-patch".

Yes.

>> > --- a/lisp/comint.el
>> > +++ b/lisp/comint.el
>> > @@ -161,7 +161,10 @@ comint-prompt-regexp
>> >  Defaults to \"^\", the null string at BOL.
>> >  
>> >  This variable is only used if the variable
>> > -`comint-use-prompt-regexp' is non-nil.
>> > +`comint-use-prompt-regexp' is non-nil.  The exception to
>> > +this is redirection.  Many commands including
>> > +`comint-redirect-send-command-to-process' use it as
>> > +`comint-redirect-finished-regexp'.
>> 
>> This paragraph sounds a bit weird, but I don't know how to reword it.
>> Maybe someone else can help.
>
> I'm not sure the addition is necessary in the first place.  What is
> its purpose? why is it useful to mention those exceptional cases?
>
>> Also, here and elsewhere, except for the first line, there should
>> generally be one empty line between paragraphs.
>
> This is not a requirement.  It's a judgment call whether an empty line
> is needed or not.

Noted.

>> > -If NO-DISPLAY is non-nil, do not show the output buffer."
>> > +If NO-DISPLAY is non-nil, do not show the output buffer.
>> > +If FINISHED-REGEXP is non-nil it is used as `comint-redirect-finished-regexp'
>> > +instead of `comint-prompt-regexp'."
>> 
>> Please clarify what "it" is.
>
> I think it's clear in this case: there's no other candidate for being
> "it" here except FINISHED-REGEXP.

When I first read this sentence, I interpretted it as:

    If F-R is non-nil, F-R is used as `c-r-f-r'.  Otherwise F-R is used
    as `c-p-r'.

I don't know.  Maybe you see it differently, in which case I'm fine with
not changing it.

-- 
Best,


RY

bug#61602: [PATCH]: comint-mode redirection

[Rah Guzar via Bug reports for GNU Emacs, the Swiss army knife of text editors]

[-- Attachment #1: Type: text/plain, Size: 3360 bytes --]


Hi Ruijie,
   Thanks for the comments.

Ruijie Yu <ruijie@netyu.xyz> writes:

> Thanks for the patch.  First of all, when sending a patch(set) for
> Emacs, you need to run something like this:
>
>     $ git format-patch
>
> and send the generated file(s).  Take a look at its manpage and ask if
> you have any questions.  What you have sent is a "diff" file, which
> bears no commit messages.  At least in Emacs contributions, patches
> should usually come together with their commit messages.
>
> And there are guidelines on commit messages, see /CONTRIBUTE on
> emacs.git.

I have attached a patch which hopefully is made properly this time.

> Further in-line comments below.
>
> Rah Guzar via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org> writes:
>
>>  This variable is only used if the variable
>> -`comint-use-prompt-regexp' is non-nil.
>> +`comint-use-prompt-regexp' is non-nil.  The exception to
>> +this is redirection.  Many commands including
>> +`comint-redirect-send-command-to-process' use it as
>> +`comint-redirect-finished-regexp'.
>
> This paragraph sounds a bit weird, but I don't know how to reword it.
> Maybe someone else can help.
>

I tried some rewording.

>>  (defvar comint-redirect-finished-regexp nil
>>    "Regular expression that determines when to stop redirection in Comint.
>>  When the redirection filter function is given output that matches this regexp,
>> -the output is inserted as usual, and redirection is completed.")
>> +the output is inserted as usual, and redirection is completed.
>> +This is an internal variable set by `comint-redirect-setup' and setting it
>> +directly has no effect.")
>
> If this is indeed a private variable, why does it contain no
> double-dashes in its name prior to your changes?
>
> Also, here and elsewhere, except for the first line, there should
> generally be one empty line between paragraphs.
>

It is not declared as a private variable but it is in effect used as
one, so documenting should prevent confusion. Some context: I wanted
to use redirection to display some documentation is a separate buffer.
However documentation sometimes contained the usual prompt and that
messed up the comint buffer. To get around it I setup the redirected
commands so that they had a custom prompt and tried to set c-r-f-r
accordingly but that didn't work and I had to fish around the comint
source to figure out why.

>> +(defvar comint-redirect-hook nil
>> +  "Hook run when a redirection finishes.")

> Does it make sense for a user to customize the hook?  If so, you should
> convert this variable into a `defcustom'.

This for better discoverability. I think comint-mode is too low-level for
most users to use it directly. But e.g. for those writing a derived mode
it is good to be aware that this hook exists without diving into source.

>> +If FINISHED-REGEXP is non-nil it is used as `comint-redirect-finished-regexp'
>> +instead of `comint-prompt-regexp'."
>
> Please clarify what "it" is.
>
> If you are referring to the change below from `cominit-prompt-regexp' to
> `(or finished-regexp comint-prompt-regexp)', then the current form is
> ambiguous, and maybe you should say something like this:
>
>     If F-R is non-nil, it is used as `c-r-f-r'.  Otherwise `c-p-r' is
>     used as `c-r-f-r'.
>

Thanks, I incorporated your suggestion.


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: 0001-Bug-61602-Tweak-comint-mode-redirection.patch --]
[-- Type: text/x-patch, Size: 3268 bytes --]

From ac814964e1885d005746e98f5010a2b400293810 Mon Sep 17 00:00:00 2001
From: Rahguzar <rahguzar@zohomail.eu>
Date: Fri, 12 May 2023 09:00:34 +0200
Subject: [PATCH] (Bug#61602) Tweak comint-mode redirection

* lisp/comint.el (redirection): New optional argument for
'comint-redirect-send-command-to-process' to explicitly
set the regexp to end redirection. Define 'comint-redirect-hook'
for easier discovery. Miscellaneous documentation fixes.
---
 lisp/comint.el | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/lisp/comint.el b/lisp/comint.el
index 682b555a33c..e6ce31f231c 100644
--- a/lisp/comint.el
+++ b/lisp/comint.el
@@ -161,7 +161,10 @@ comint-prompt-regexp
 Defaults to \"^\", the null string at BOL.
 
 This variable is only used if the variable
-`comint-use-prompt-regexp' is non-nil.
+`comint-use-prompt-regexp' is non-nil.  An exception to
+this is redirection.  Many commands including
+`comint-redirect-send-command-to-process' use `comint-prompt-regexp'
+to detect the end of redirection.
 
 Good choices:
   Canonical Lisp: \"^[^> \\n]*>+:? *\" (Lucid, franz, kcl, T, cscheme, oaklisp)
@@ -3637,7 +3640,13 @@ comint-redirect-output-buffer
 (defvar comint-redirect-finished-regexp nil
   "Regular expression that determines when to stop redirection in Comint.
 When the redirection filter function is given output that matches this regexp,
-the output is inserted as usual, and redirection is completed.")
+the output is inserted as usual, and redirection is completed.
+
+This is an internal variable set by `comint-redirect-setup' and setting it
+directly has no effect.")
+
+(defvar comint-redirect-hook nil
+  "Normal hook run when a redirection finishes.")
 
 (defvar comint-redirect-insert-matching-regexp nil
   "If non-nil, the text that ends a redirection is included in it.
@@ -3833,11 +3842,14 @@ comint-redirect-send-command
 
 ;;;###autoload
 (defun comint-redirect-send-command-to-process
-  (command output-buffer process echo &optional no-display)
+  (command output-buffer process echo &optional no-display finished-regexp)
   "Send COMMAND to PROCESS, with output to OUTPUT-BUFFER.
 With prefix arg, echo output in process buffer.
 
-If NO-DISPLAY is non-nil, do not show the output buffer."
+If NO-DISPLAY is non-nil, do not show the output buffer.
+FINISHED-REGEP is set as `comint-redirect-finished-regexp'
+when it is non-nil, otherwise `comint-prompt-regexp' is used
+as `comint-redirect-finished-regexp'."
   (interactive "sCommand: \nBOutput Buffer: \nbProcess Buffer: \nP")
   (let* (;; The process buffer
 	 (process-buffer (if (processp process)
@@ -3857,9 +3869,9 @@ comint-redirect-send-command-to-process
       ;; Set up for redirection
       (comint-redirect-setup
        output-buffer
-       (current-buffer)                 ; Comint Buffer
-       comint-prompt-regexp             ; Finished Regexp
-       echo)                            ; Echo input
+       (current-buffer)                          ; Comint Buffer
+       (or finished-regexp comint-prompt-regexp) ; Finished Regexp
+       echo)                                     ; Echo input
 
       ;; Set the filter.
       (add-function :around (process-filter proc) #'comint-redirect-filter)
-- 
2.40.1

bug#61602: [PATCH]: comint-mode redirection

[Rah Guzar via Bug reports for GNU Emacs, the Swiss army knife of text editors]

Hi Eli,

Eli Zaretskii <eliz@gnu.org> writes:

>> >  This variable is only used if the variable
>> > -`comint-use-prompt-regexp' is non-nil.
>> > +`comint-use-prompt-regexp' is non-nil.  The exception to
>> > +this is redirection.  Many commands including
>> > +`comint-redirect-send-command-to-process' use it as
>> > +`comint-redirect-finished-regexp'.
>>
>> This paragraph sounds a bit weird, but I don't know how to reword it.
>> Maybe someone else can help.
>
> I'm not sure the addition is necessary in the first place.  What is
> its purpose? why is it useful to mention those exceptional cases?

I think it is useful for those writing a comint derived mode who might
be tempted to not set 'comint-prompt-regexp' since it is going to be
unused by default. Redirection is an important enough facility in
my opinion for this to be pointed out.

bug#61602: [PATCH]: comint-mode redirection

[Andreas Schwab]

On Mai 12 2023, Ruijie Yu via "Bug reports for GNU Emacs, the Swiss army knife of text editors" wrote:

>>> > -If NO-DISPLAY is non-nil, do not show the output buffer."
>>> > +If NO-DISPLAY is non-nil, do not show the output buffer.
>>> > +If FINISHED-REGEXP is non-nil it is used as `comint-redirect-finished-regexp'
>>> > +instead of `comint-prompt-regexp'."
>>> 
>>> Please clarify what "it" is.
>>
>> I think it's clear in this case: there's no other candidate for being
>> "it" here except FINISHED-REGEXP.
>
> When I first read this sentence, I interpretted it as:
>
>     If F-R is non-nil, F-R is used as `c-r-f-r'.  Otherwise F-R is used
>     as `c-p-r'.
>
> I don't know.  Maybe you see it differently, in which case I'm fine with
> not changing it.

Perhaps a better wording:

FINISHED-REGEXP is used as `comint-redirect-finished-regexp'.  If
FINISHED-REGEXP is nil it defaults to `comint-prompt-regexp'.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."