bug#66993: [PATCH] project.el: avoid asking user about project-list-file lock

[Dmitry Gutov <dmitry@gutov.dev>]

On 18/11/2023 17:48, sbaugh@catern.com wrote:
> +(defcustom project-list-file-save 'on-exit
> +  "When to save `project-list-file'.
> +
> +If non-nil, the list of known projects is saved in
> +`project-list-file'.
> +
> +If set to `on-change', the list is saved every time it changes.
> +If set to `on-exit', the list is saved when Emacs exits.  If set
> +to `on-change-and-exit', the list is saved in both cases."
> +  :type '(choice (const :tag "Save on change" on-change)
> +                 (const :tag "Save when exiting" on-exit)
> +                 (const :tag "Save on change and when exiting" on-change-and-exit))
> +  :group 'project
> +  :version "30.1")

I think I'd rather we change the behavior to straight away save on exit, 
no customization needed.

For most users the observable behavior will be the same, but we won't 
have to keep supporting the 'on-change' value later if/when we migrate 
to use savehist-mode instead.