Re: RCS, again: another removed functionality: undo last-checkin

[Dmitry Gutov]

On 09/22/2015 10:05 PM, Eli Zaretskii wrote:

> > And if we're going to warn about doing rollback either way, the second
> > warning is more likely to fly under the user's radar ("why are you
> > asking me this again? yes already!"), which is kinda bad.
>
> I meant a single warning, not 2 of them.

That sounds non-trivial: how is generic code to know that the Git 
backend intends to fall back to 'git revert'? Would warnings be 
backend-specific?

And having just one warning means it has to convey both the sense of 
danger *and* the choice of Git command to be used.

Thinking about the issue more, 'git reset' is not that dangerous. 
*Especially* if the changes have been pushed to the remote. So even if 
you 'git reset HEAD^', but the commit has been pushed already, you can 
undo the operation simply by doing 'git pull', among other ways.

But 'git reset' without '--hard' sets you up to easily create 
conflicting commits, so it does invite confusion.

So I think vc-rollback should error out (by default; that could be 
customizable) when the user tries to back out of an already-published 
commit (and the backend knows how to detect that), and suggest using 
vc-revert. Which will be a separate command. If those names seem too 
similar to someone, I welcome better suggestions.