bug#62260: 30.0.50; [PATCH] Restrict auto-save file mode

[Eli Zaretskii]

> From: Manuel Giraud <manuel@ledu-giraud.fr>
> Cc: 62260@debbugs.gnu.org
> Date: Sun, 19 Mar 2023 12:43:02 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > More generally: what problems are you trying to solve here?  If this
> > code causes some problems, please describe them, and let's see whether
> > and how we should fix them.
> 
> You're right.  I should have start from here.  So it all start with a
> recurring message I get from TRAMP whenever I access a root file (via
> sudo method) for the first time.  It asks:
> 
>   "Autosave file on local temporary directory, do you want to continue?"
> 
> I answer "yes" but it seems that it can potentially leak root data
> through auto-save files.  Looking at the code that asks this question
> (tramp.el:6528), I see that I can set
> 'tramp-allow-unsafe-temporary-files' to t and I won't see the question
> again... but the leakage is still possible.  So I guess what I want is
> an option to stop auto-save entirely in those cases.
> 
> >From there, I've looked at how auto-save work and I ask myself: "maybe
> instead of such an option, I could limit others rights on auto-save
> files".  And that's how I came up with this patch.

So this is limited to Tramp and how it handles auto-saving?  Adding
Michael, in case he has ideas for how to solve this issue.