Re: [External] : Turning on savehist-mode by default

[Yuri Khan]

On Sun, 19 Nov 2023 at 15:26, Eli Zaretskii <eliz@gnu.org> wrote:

> > > Please don't forget there is also `desktop.el'
> > > that is a superset of `savehist.el'
> >
> > Is it though? I’m using ‘desktop-save-mode’, not observing
> > preservation of histories, and not seeing any user option in the
> > Desktop group that would shout to me “enable this to save all
> > histories”. I see ‘file-name-history’ in ‘desktop-globals-to-save’ but
> > I wouldn’t like to whitelist all the histories I care about.
>
> Why not?

Why would I? Histories are user data. User data is precious. Losing
user data on a restart is a bug. (Slightly exaggerating.)

I can see three reasons for *not* saving histories: (1) risk of
information disclosure if sensitive data such as passwords is stored
in histories; (2) reduced startup performance if too much history gets
accumulated; and (3) cross-process interference if the application is
typically running in multiple instances. (1) is solved by a blacklist
(opt-out for a few specific histories), (2) by pruning saved histories
to some configurable maximum depth, and (3) by saying Emacs is not
typically used like that[citation needed].

(I remember seeing an implementation of input histories that also
allowed pinning important entries so they would never be pruned, and
explicitly deleting specific entries, right from the UI that displayed
history entries.)

> I do precisely that, FWIW.  It's a one-time configuration,
> so not a lot of effort.

It’s only a one-time configuration if your workflow is constant. If I
start using a feature I had not been using previously, its histories
will initially not be saved, and I’ll have to interrupt my work and
amend my configuration. So it’s a recurring cost.