bug#60080: 28.2; Double-click selection cannot be customized

[Sean Devlin <spd@toadstyle.org>]

Hi Eli,

> On Dec 15, 2022, at 2:33 AM, Eli Zaretskii <eliz@gnu.org> wrote:
> 
>> From: Sean Devlin <spd@toadstyle.org>
>> Date: Wed, 14 Dec 2022 19:40:22 -0500
>> 
>> I'd like to customize Emacs such that when I double-click on a word,
>> the entire enclosing symbol is selected. In other words, it should
>> behave more like the latter case of double-clicking on a character with
>> symbol syntax.
> 
> Does the patch below do what you want?
> 
> If it does, we could provide this as an optional behavior, conditioned
> by some new user option.

Yes, this seems to do the trick.

I agree that a user option would make sense.

Thanks for looking at this so quickly!

> 
> diff --git a/lisp/mouse.el b/lisp/mouse.el
> index f72ab4f..ced7a92 100644
> --- a/lisp/mouse.el
> +++ b/lisp/mouse.el
> @@ -1803,7 +1803,11 @@ mouse-skip-word
> If DIR is positive skip forward; if negative, skip backward."
>   (let* ((char (following-char))
> 	 (syntax (char-to-string (char-syntax char))))
> -    (cond ((string= syntax "w")
> +    (cond ((bounds-of-thing-at-point 'symbol)
> +           (goto-char (if (< dir 0)
> +                          (car (bounds-of-thing-at-point 'symbol))
> +                        (cdr (bounds-of-thing-at-point 'symbol)))))
> +          ((string= syntax "w")
> 	   ;; Here, we can't use skip-syntax-forward/backward because
> 	   ;; they don't pay attention to word-separating-categories,
> 	   ;; and thus they will skip over a true word boundary.  So,