Subject: bug#71049: async-shell-command ends with "Process *Async Shell Command* finished" when remote "direct-async-process"

From: Dmitry Gutov <[email-masked]>
Date: Sat, 1 Jun 2024 04:21:46 +0300

On 31/05/2024 21:05, Eli Zaretskii wrote:
>> Date: Fri, 31 May 2024 19:24:10 +0300
>> Cc:[email-masked],[email-masked]
>> From: Dmitry Gutov<[email-masked]>
>>
>> On 31/05/2024 08:53, Eli Zaretskii wrote:
>>
>>>> 1) [first patch] We can add a new major mode, for 'M-&' to use instead
>>>> of the full-blown 'shell-mode' - it could be very simple: just apply
>>>> font-lock keywords and maybe set list-buffers-directory.
>>> I think I'm okay with this.  (It needs to be prominently documented,
>>> of course.)
>> In NEWS?
> There, but also in the doc string of M-&, and maybe also in the doc
> string of shell-mode-hook.
> 
>>> But we need a documented way for people to get previous
>>> behavior if they want that.  How would that work?
>> If we really needed the capability to rollback the change, I suppose we
>> could add a defvar pointing to the major mode to use. I.e.
>>
>>     (defvar async-shell-command-major-mode #'shell-command-mode)
> That could work, yes.

How about this?

diff --git a/etc/NEWS b/etc/NEWS
index d058acc3572..40407edf4e3 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1881,6 +1881,10 @@ than regular expressions, but less complexity than context-free
 grammars.  The Info manual "(elisp) Parsing Expression Grammars" has
 documentation and examples.
 
+** New major mode 'shell-command-mode'.
+This mode is used by default for the output of 'async-shell-command'.
+To revert to the previous behavior, set 'async-shell-command-mode' to
+'shell-mode'.
 
 * Incompatible Lisp Changes in Emacs 30.1
 
diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index 9385b023392..795a9e667c7 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -5247,8 +5247,13 @@ tramp-handle-shell-command
 	      ;; Display output.
 	      (with-current-buffer output-buffer
 		(setq mode-line-process '(":%s"))
-		(unless (eq major-mode 'shell-mode)
-		  (shell-mode))
+                (cond
+                 ((boundp 'async-shell-command-mode)
+                  ;; Emacs 30+
+                  (unless (eq major-mode async-shell-command-mode)
+                    (funcall async-shell-command-mode)))
+                 ((not (eq major-mode 'shell-mode))
+                  (shell-mode)))
 		(set-process-filter p #'comint-output-filter)
 		(set-process-sentinel p #'shell-command-sentinel)
 		(when error-file
diff --git a/lisp/shell.el b/lisp/shell.el
index e6b315ee5c0..edee46cdb4d 100644
--- a/lisp/shell.el
+++ b/lisp/shell.el
@@ -838,6 +838,13 @@ shell-write-history-on-exit
       (with-current-buffer buf
         (insert (format "\nProcess %s %s\n" process event))))))
 
+(define-derived-mode shell-command-mode comint-mode "Shell"
+  "Major mode for the output of asynchronous `shell-command'."
+  (setq-local font-lock-defaults '(shell-font-lock-keywords t))
+  ;; See comments in `shell-mode'.
+  (setq-local ansi-color-apply-face-function #'shell-apply-ansi-color)
+  (setq list-buffers-directory (expand-file-name default-directory)))
+
 ;;;###autoload
 (defun shell (&optional buffer file-name)
   "Run an inferior shell, with I/O through BUFFER (which defaults to `*shell*').
diff --git a/lisp/simple.el b/lisp/simple.el
index ae8a824cb54..fa745f10148 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -31,7 +31,6 @@
 (eval-when-compile (require 'cl-lib))
 
 (declare-function widget-convert "wid-edit" (type &rest args))
-(declare-function shell-mode "shell" ())
 
 ;;; From compile.el
 (defvar compilation-current-error)
@@ -4487,9 +4486,10 @@ async-shell-command
 
 The output appears in OUTPUT-BUFFER, which could be a buffer or
 the name of a buffer, and defaults to `shell-command-buffer-name-async'
-if nil or omitted.  That buffer is in shell mode.  Note that, unlike
-with `shell-command', OUTPUT-BUFFER can only be a buffer, a buffer's
-name (a string), or nil.
+if nil or omitted.  That buffer is in major mode specified by the
+variable `async-shell-command-mode'.  Note that, unlike with
+`shell-command', OUTPUT-BUFFER can only be a buffer, a buffer's name
+(a string), or nil.
 
 You can customize `async-shell-command-buffer' to specify what to do
 when the buffer specified by `shell-command-buffer-name-async' is
@@ -4533,6 +4533,9 @@ async-shell-command
 (declare-function comint-output-filter "comint" (process string))
 (declare-function comint-term-environment "comint" ())
 
+(defvar async-shell-command-mode 'shell-command-mode
+  "Major mode to use for the output of asynchronous `shell-command'.")
+
 (defun shell-command (command &optional output-buffer error-buffer)
   "Execute string COMMAND in inferior shell; display output, if any.
 With prefix argument, insert the COMMAND's output at point.
@@ -4543,9 +4546,9 @@ shell-command
 
 If COMMAND ends in `&', execute it asynchronously.
 The output appears in the buffer whose name is specified
-by `shell-command-buffer-name-async'.  That buffer is in shell
-mode.  You can also use `async-shell-command' that automatically
-adds `&'.
+by `shell-command-buffer-name-async'.  That buffer is in major mode
+specified by the variable `async-shell-command-mode'.  You can also use
+`async-shell-command' that automatically adds `&'.
 
 Otherwise, COMMAND is executed synchronously.  The output appears in
 the buffer named by `shell-command-buffer-name'.  If the output is
@@ -4721,7 +4724,7 @@ shell-command
 		  (setq proc
 			(start-process-shell-command "Shell" buffer command)))
 		(setq mode-line-process '(":%s"))
-                (shell-mode)
+                (funcall async-shell-command-mode)
                 (setq-local revert-buffer-function
                             (lambda (&rest _)
                               (async-shell-command command buffer)))