Re: trunk r115265: * lisp/vc/vc-dispatcher.el (vc-log-edit): Setup the Summary&Author headers.

[Dmitry Gutov]

On 02.12.2013 15:53, Stefan Monnier wrote:
> Go to your nearest file buffer and type: SPC C-x k RET
> As you can see, you did choose the buffer to kill and yet you get
> prompted to confirm you want to kill that buffer despite its
> unsaved changes.

Ah, thanks, now I get it. This issue is not new, so it didn't seem too 
important.

> I think it's good to try and make the *VC-Log* (and the *mail*) buffers
> behave similarly to file buffers in this respect.

I don't see this problem with mail. When I'm in a message-mode buffer 
(say, writing a reply from Gnus), and I press C-x k RET, Emacs warns me 
that the buffer is modified and asks for confirmation.

See the small patch at the bottom for log-edit. It seems to work, but I 
fear it may complicate some scenarios where buffers are killed 
automatically.

> It's probably the case that log-edit-hide-buf needs to be revisited,
> since it dates to before the rewrite of display-buffer, where Martin
> arranged to better be able to "undo" a display-buffer (via bury-buffer
> or quit-window).

Guess so.

=== modified file 'lisp/vc/log-edit.el'
--- lisp/vc/log-edit.el 2013-12-02 22:13:51 +0000
+++ lisp/vc/log-edit.el 2013-12-02 22:54:52 +0000
@@ -476,6 +476,7 @@
   (set (make-local-variable 'font-lock-defaults)
        '(log-edit-font-lock-keywords t))
   (make-local-variable 'log-edit-comment-ring-index)
+  (add-hook 'kill-buffer-hook 'log-edit-kill-buffer-prompt nil t)
   (hack-dir-local-variables-non-file-buffer))

 (defun log-edit-hide-buf (&optional buf where)
@@ -551,6 +552,11 @@
     (quit-windows-on buf)
     (kill-buffer buf)))

+(defun log-edit-kill-buffer-prompt ()
+  (unless (ring-member log-edit-comment-ring (buffer-string))
+    (or (yes-or-no-p "Discard the comment?")
+        (user-error "Aborted"))))
+
 (defun log-edit-files ()
   "Return the list of files that are about to be committed."
   (ignore-errors (funcall log-edit-listfun)))