bug#62750: 29.0.50; Commands 'package-update' and 'package-update-all' should be called '*-upgrade'

[Dmitry Gutov <dmitry@gutov.dev>]

On 24/04/2023 20:28, Adam Porter wrote:
> On 4/24/23 07:02, Eli Zaretskii wrote:
> 
>> Me, I have only one potential issue: since "update" just means "delete
>> the installed version, then install another version", it could be
>> easily made to downgrade, not just to upgrade.  So if we ever would
>> like to allow downgrading, the new names will get in the way.  But if
>> this is not an issue we should be bothered about, it's fine by me.
> 
> IMHO, a command to downgrade ought to be a separate command with a 
> different name--not only to reduce confusion, but because downgrading 
> packages is an operation that is more likely to require manual user 
> intervention, such as recompiling other packages that depend on the 
> downgraded package (e.g. if struct or macro definitions change, or 
> symbols disappear).

That might also be the case when upgrading a package that some others 
depend on (newer version could also have macros deleted or renamed).

Either way, though, we could make it a separate command.

Or even augment the current one: (package-upgrade 'name 
"some-older-version") has a similar feel to (forward-char -1), not 
exactly unfamiliar to us.

Would "update" be a more proper term to cover both upgrading and 
downgrading? I'm not sure about that. Aside from "downgrade", I would 
probably say "revert" or "install an older version". E.g. when using 
apt-get, the relevant subcommand would be "install".

> It's easy enough to cause that problem when upgrading, and much more 
> likely when downgrading, to the extent that it's arguable that a command 
> to downgrade shouldn't exist, because users who want to downgrade a 
> package should be prepared to deal with the potential fallout.

Or that. We don't keep older versions around in ELPA anyway, so for now 
the question is moot.