Re: C-x C-v considered harmful

[Juri Linkov]

> The variable `kill-buffer-query-functions' is nil by default,
> so maybe it's better to implement this confirmation in Fkill_buffer
> instead of the hook `kill-buffer-query-functions'?

Looking again at `find-alternate-file' convinces me that the right
solution is to use the `kill-buffer-query-functions' hook.

`find-alternate-file' explicitly runs this hook as:

  (run-hook-with-args-until-failure 'kill-buffer-query-functions)

and binds it to nil around killing the buffer to not ask again:

  (let ((kill-buffer-query-functions))
    (kill-buffer obuf))

So there is no good way to prevent asking a confirmation about a running
process in Fkill_buffer.

Asking a confirmation about a modified file buffer could be moved to the
`kill-buffer-query-functions' hook as well because this will avoid
duplicating this question in `find-alternate-file'.  But at least now
I propose to add a process confirmation to `kill-buffer-query-functions':

Index: lisp/files.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/files.el,v
retrieving revision 1.1055
diff -u -r1.1055 files.el
--- lisp/files.el       5 Jul 2009 22:15:37 -0000       1.1055
+++ lisp/files.el       13 Jul 2009 20:03:47 -0000
@@ -1441,6 +1441,16 @@
       (other-window 1)
       (find-alternate-file filename wildcards))))
 
+(defun process-kill-buffer-query-function ()
+  "Ask before killing a buffer that has a running process."
+  (let ((process (get-buffer-process (current-buffer))))
+    (or (not process)
+        (not (memq (process-status process) '(run stop open listen)))
+        (not (process-query-on-exit-flag process))
+        (yes-or-no-p "Buffer has a running process; kill it? "))))
+
+(add-hook 'kill-buffer-query-functions 'process-kill-buffer-query-function)
+
 (defun find-alternate-file (filename &optional wildcards)
   "Find file FILENAME, select its buffer, kill previous buffer.
 If the current buffer now contains an empty file that you just visited

-- 
Juri Linkov
http://www.jurta.org/emacs/