bug#25478: 26.0.50; No hooks are called when auto-saving

[Eli Zaretskii <eliz@gnu.org>]

> From: Philipp Stephani <p.stephani2@gmail.com>
> Date: Sat, 22 Apr 2017 19:01:50 +0000
> Cc: rgm@gnu.org, 25478@debbugs.gnu.org
> 
> Here's a patch. 

Thanks.  A few minor comments:

> --- a/doc/emacs/files.texi
> +++ b/doc/emacs/files.texi
> @@ -1040,14 +1040,13 @@ Auto Save Files
>  this happens, save the buffer with @kbd{C-x C-s}, or use @kbd{C-u 1 M-x
>  auto-save-mode}.
>  
> -@vindex auto-save-visited-file-name
> +@vindex auto-save-visited-mode

I wonder whether auto-save-files-mode is a better name, as the
"visited" part looks now out of place.  (If you do rename it, please
also rename the time-interval variable accordingly.)

> +in a separate auto-save file, enable the global minor mode
> +@code{auto-save-visited-mode}.  In this mode, auto-saving is very
> +similar to explicit saving.

"Very similar" begs the question "what's the difference?"  If there
are differences, let's describe them; if there aren't, let's say
"identical to" or "the same as".

>                                Note that this mode is orthogonal to the
> +@code{auto-save} mode described above; you can enable both at the same
> +time.

But if auto-save mode is enabled and auto-save-visited-file-name is
set, then this new mode will not auto-save, right?  This should be
documented.

> @@ -1091,6 +1090,13 @@ Auto Save Control
>  a while; second, it may avoid some auto-saving while you are actually
>  typing.
>  
> +@vindex auto-save-visited-interval

I suggest to mention this variable where you describe the new mode,
since the two descriptions are several tens of lines apart.

> +  When @code{auto-save-visited-mode} is enabled, Emacs will auto-save
> +file-visiting buffers after five seconds of idle time.  You can
> +customize the variable @code{auto-save-visited-interval} to change the
> +idle time interval.  @code{auto-save-interval} and
> +@code{auto-save-timeout} have no effect on this mode.

I think the last sentence should be part of the description of the
mode, not of the variable.  Doing so will also provide a good
opportunity to mention auto-save-visited-interval.

> +(defcustom auto-save-visited-interval 5
> +  "Interval in seconds for `auto-save-visited-mode'.
> +If `auto-save-visited-mode' is enabled, Emacs will save all
> +buffers visiting a file to the visited file after it has been
> +idle for `auto-save-visited-interval' seconds."
> +  :group 'auto-save
> +  :type 'number
> +  :set (lambda (symbol value)
> +         (set-default symbol value)
> +         (when auto-save--timer
> +           (timer-set-idle-time auto-save--timer value :repeat))))

Please add a :version tag to new defcustoms.

> +(define-minor-mode auto-save-visited-mode
> +  "Toggle automatic saving to file-visiting buffers on or off.
> +With a prefix argument ARG, enable regular saving of all buffers
> +vising a file if ARG is positive, and disable it otherwise.
   ^^^^^^
A typo.