bug#62413: 29.0.60; [PATCH] save-place-mode cannot restore saved position

[Ruijie Yu via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Liu Hui <liuhui1610@gmail.com> writes:

> Eli Zaretskii <eliz@gnu.org> 于2023年3月30日周四 13:33写道：
>>
>> I think there's a cleaner way: a defcustom can have a :set function,
>> which is called each time the variable is customized; this setter
>> function should be defined for a defcustom when changing its value has
>> non-trivial effects.  So we can define such a setter function to
>> rewrite the list, and document in the doc string of the defcustom that
>> users should not just set the value with setq, but instead use either
>> setopt or "M-x customize-variable".  WDYT?
>
> OK, I think it is good. Please see the attached patch.
>
> [2. text/x-patch; 0001-Restore-positions-reliably-for-abbreviated-file-name.patch]...

Two minor comments below.

> @@ -90,8 +92,32 @@ save-place-forget-unreadable-files
>  (defcustom save-place-abbreviate-file-names nil
> [...]
> +  :set (lambda (sym val)
> +         (set-default sym val)
> +         (let ((fun (if val 'abbreviate-file-name 'expand-file-name)))

I believe function quotes "#'" are preferred over simple quotes "'" when
dealing with functions.

> @@ -214,7 +241,11 @@ save-place-to-alist
>  			    ((and (derived-mode-p 'dired-mode) directory)
>  			     (let ((filename (dired-get-filename nil t)))
>  			       (if filename
> -				   `((dired-filename . ,filename))
> +                                   (list
> +                                    (cons 'dired-filename
> +                                          (if save-place-abbreviate-file-names
> +                                              (abbreviate-file-name filename)
> +                                            filename)))

It seems that you rewrote the quote-backquote thing with regular
list-cons construct -- no comments on that.  I noticed that here, and in
a few other places, you are reusing the exact `if' construct multiple
times.  Does that warrant defining a helper function?

Also, while I was about to send the mail, regarding the docstring of
`save-place-abbreviate-file-names', instead of letting the user enable
`save-place-mode', would it be better if you directly call facilities in
saveplace to load `save-place-alist' from file system, within your :set
function?

-- 
Best,


RY