bug#27822: [PATCH] do not auto-remove external packages (fixes #27822)

[Stefan Monnier]

[ Please don't crosspost between bugs and emacs-devel.  ]

> package-autoremove however will still attempt to remove them. My feeling
> is that any package which is not directly in 'package-user-dir shouldn't
> be autoremoved.

AFAIK packages installed via dpkg can't be removed (lack of access
rights), so attempting to remove them is not that big of a deal, is it?
Or does it signal an error, prevent local packages from being
auto-removed, or something (I mean, beside the philosophical argument,
does it result in an actual harmful behavior in practice)?

> The following patch checks whether a package has been _directly_ installed
> into `package-user-dir' before marking it eligible for auto-removal.

Looks good to me,


        Stefan