Re: Removing rollback from VC mode - request for comment

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> Actually, I think most VCS can support it one way or another.
> It's not hard to simulate using what in git terms is a reverse cherry pick.

IIUC "reverse cherry pick" adds a new commit, so it's a different
operation, which does not require any special support (it's a normal
cherry pick, basically).

> But modifying history in place is very difficult to do with a good outcome.

The "clean" way to look at this feature is:
- create a new branch BAR off of the target revision.
- delete the current branch FOO.
- rename BAR to FOO.
- adjust the current checkout, if needed, in accordance with the new FOO.
AFAIK, most current VCS offer those operations.

> It'll take a while, though.  Michael Albinus and I are finding a lot
> of bit-rot.  He just told me that six of the eight working-revision
> backend functions don't work right. Much repair is required before
> adding new features.

That's OK, but:
- please make sure you get back promptly to replacing the removed features.
- the more important the feature, the shorter the delay before you
  replace it.



        Stefan