bug#74604: 30.0.92; FR: M-x package-upgrade - offer an option to show a diff on upgrade

[Daniel Mendler via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Ship Mints <shipmints@gmail.com> writes:

> To help determine the value/risk of a
> package install or update, I'd think it better to show this in advance.
> Daniel's diff suggestion is similar but more technical.

I think your idea of adding an option to show the change log is good. It
would be nice to have a `package-upgrade-review' option which could be
set to `nil', `news' or to `diff'.

But I want to emphasize that your suggestion misses the security aspect.
Security is the main reason why I made the proposal. The goal is to make
it easier and more convenient for users (yes, users who are "technical"
and familiar with Elisp) to assess the safety of package upgrades and
possibly report any irregularities to the package archive maintainers.
While packages are commonly reviewed at the time of their inclusion in
package archives, this is often not the case later on.

My proposal does not address or affect the first time installation of a
package. At this time it doesn't make sense to show a "diff" and the
user must first check the package closely anyway.

Daniel