Re: feature/package+vc 04c4c578c7 3/4: Allow for packages to be installed directly from VCS

[Philip Kaludercic <philipk@posteo.net>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Philip Kaludercic <philipk@posteo.net>
>> Cc: emacs-devel@gnu.org
>> Date: Sat, 15 Oct 2022 15:52:28 +0000
>> 
>> Philip Kaludercic <philipk@posteo.net> writes:
>> 
>> > - The ability to update a package using `package-upgrade'[0]
>> 
>> [...]
>> 
>> > [0] This feature is currently broken because it tries to use `vc-pull'
>> >     which refuses to work if any changes have been made.  This is an
>> >     issue as package-vc-fetch tries to modify the list of ignored files
>> >     in a repository (think of .gitignore).  It will either be necessary
>> >     to change how vc-pull works or try to do something with
>> >     vc-log-incoming + vc-merge.
>> 
>> Does anyone know if it is possible to do this?
>
> Where is the code which fails vc-pull if there are changes in the
> working tree?  is it specific to some backend, perhaps?  The doc
> string says:
>
>   On a non-distributed version control system, update the current
>   fileset to the tip revisions.  For each unchanged and unlocked
>   file, this simply replaces the work file with the latest revision
>   on its branch.  If the file contains changes, any changes in the
>   tip revision are merged into the working file.
>
> Note that last sentence.  So this ought to work, and if it doesn't,
> it's a bug, I guess?

I have re-tested it and I was mistaken, the issue was with Git.  Sadly I
cannot reproduce it right now, but I will try to re-trigger it.

> From the shell prompt, "git pull" will fail if the changes are in the
> same file as one of those whose changes are brought in by the pull,
> but either using --rebase or maybe the stash/pull/unstash dance should
> take care of that, I guess?

Right, I believe it was something along these lines but this is
something that is difficult to automate.

> Or am I missing something?