bug#29972: 25.3; dired-hide-details-mode does not persist in desktop session

[Jimmy Yuen Ho Wong]

Actually I would question why we have minor modes not added to minor-mode-alist at all just because both lighter and keymap are missing.

What do you think about changing define-minor-mode?

On Fri, 5 Jan 2018 at 2:26 pm, Eli Zaretskii <eliz@gnu.org> wrote:

> From: Jimmy Yuen Ho Wong <wyuenho@gmail.com>
> Date: Fri, 5 Jan 2018 13:08:35 +0000
> Cc: 29972@debbugs.gnu.org
>
> I don't believe so. I've looked at a number of approaches.
>
> 1. `desktop-minor-mode-handlers` on desktop-read
>     Not going to be consulted unless `dired-hide-details-mode` is saved as a buffer minor mode.
> 2. `desktop-minor-mode-table` on desktop-save
>     If `dired-hide-details-mode` is not in `minor-mode-alist`, `desktop-minor-mode-table` will not even be
> consulted.
> 3. `desktop-locals-to-save`
>     This does save the minor mode local variable to the desktop file, but desktop won't be able to restore the
> minor mode because minor modes are activated before buffer local variables are restored, not after.
>
> So the only choices left to me are:
> - :lighter ""
> - (add-minor-mode 'dired-hide-details-mode "")
>
> Either way adds an empty string as a lighter, and the second option makes you ask why you are declaring
> *and* adding a minor mode, so I picked the first option. It's more concise.

Then maybe we need a new, more thorough customization facility for
desktop.el, or a change in the facilities you tried to make them
handle this case as well.  It doesn't sound right to me to make tricky
changes in a minor mode just so it could be restored by desktop.el.