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

[Dmitry Gutov <dgutov@yandex.ru>]

On 01.12.2013 23:10, Stefan Monnier wrote:
> In the case of *VC-Log* we could have a kill-buffer-hook which prompts
> the user and aborts the kill if the user says he doesn't want to throw
> away his incomplete comment.  But as you point out below, we could also
> instead have a kill-buffer-hook which saves the incomplete comment to
> log-edit-comment-ring so the buffer can be deleted without losing
> valuable info and hence without prompting.

kill-buffer-hook runs when the user already chose to kill the current 
buffer (i.e. called kill-buffer and picked the current one), so that 
looks wasteful, unless the prompt is triggered by a new command that 
doesn't otherwise ask for any user input.

> As long as the data is stored in log-edit-comment-ring I think it's OK
> to kill without prompting.

Ok, so I went ahead and installed some changes in 115345 that hopefully 
aren't too far from what you imagined.

`log-edit-kill-buffer' does a bunch of different stuff, so I feel its 
presence as a separate command is justified.

I've also tried to put `log-edit-hide-buf' in kill-buffer-hook instead, 
but this way, opening log-edit buffer and then closing it via 
`log-edit-kill-buffer' made adjacent vertical splits (when present) jump 
too far, AFAICT because then `quit-windows-on' is called on the log-edit 
buffer before the log-edit-files window is deleted.

Also see the FIXME in log-edit-hide-buf.