bug#10564: 24.0.92; octave-kill-process kills octave process without warning user

[Phillip Garland <pgarland@gmail.com>]

I recently started using octave and discovered a frustrating problem
with octave mode. It's too easy to accidently kill the inferior octave
process.

C-c C-i l executes a line of octave code from an octave buffer
C-c C-i k kills the inferior octave process (octave-kill-process)

Sometimes, when I want to execute a line of code, my finger slipped,
hitting the 'k' key instead of the 'l' key, and the octave process is
immediately killed, losing the results of my computations. Right now,
octave-kill-process kills the octave process without double-checking
with the user. It does ask if you really want to kill the inferior
octave buffer, but at that point, the process has already been killed.

Right now octave-kill-buffer is defined like this:

(defun octave-kill-process ()
  "Kill inferior Octave process and its buffer."
  (interactive)
  (if inferior-octave-process
      (progn
	(process-send-string inferior-octave-process "quit;\n")
	(accept-process-output inferior-octave-process)))
  (if inferior-octave-buffer
      (kill-buffer inferior-octave-buffer)))

There seems to me to be at least three ways to solve this
problem. octave-kill-process could just call kill-buffer and have
kill-buffer kill the octave process:

(defun octave-kill-process ()
  "Kill inferior Octave process and its buffer."
  (interactive)
  (if inferior-octave-buffer
      (kill-buffer inferior-octave-buffer)))

The disadvantage of this is that there is no way to kill the process but
retain the inferior octave buffer (if you wanted to keep a record of your
octave session).

Alternatively, octave kill-process could first query the user about
killing the process, then if they kill the process, query them about
killing the inferior octave buffer:

(defun octave-kill-process ()
  "Kill inferior Octave process and its buffer."
  (interactive)
  (if (and inferior-octave-process
           (yes-or-no-p
            (format "Really kill the running Octave process? ")))
      (progn
        (process-send-string inferior-octave-process "quit;\n")
        (accept-process-output inferior-octave-process)
        (if inferior-octave-buffer
            (kill-buffer inferior-octave-buffer)))))

It's a little annoying to be queried twice, first to kill the process,
second to kill the buffer, when killing both is probably the common
case, but this seems like the least worst solution to me.

Finally, octave-kill-buffer could just kill the inferior octave process
and leave the inferior octave buffer around for the user to clean up:

(defun octave-kill-process ()
  "Kill inferior Octave process"
  (interactive)
  (if (and inferior-octave-process
           (yes-or-no-p
            (format "Really kill the running Octave process? ")))
      (progn
        (process-send-string inferior-octave-process "quit;\n")
        (accept-process-output inferior-octave-process))))

Thanks!
~Phillip


In GNU Emacs 24.0.92.1 (x86_64-unknown-linux-gnu, GTK+ Version 2.24.8)
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