Re: 4 minor suggestions for files.el

[Richard Stallman]

    > I think that the correct way for check-in and update to interact with
    > M-x undo is to transpose the old undo list somehow to the buffer as it
    > has been updated.

    That's what undo-in-region does.

undo-in-region does a special case of this.  It does not handle the
generality that would be needed for this, and I think that would require
new methods.

    > Likewise, if I edit the buffer and then do a CVS update, I should
    > then be able to undo the edit I made, but not the changes made by
    > the CVS update.

    Why not ?

When you do a CVS update, you don't know what changes are getting
merged in.  You often don't see them; they are in parts of the file
where you have not been working.

If a single undo operation would undo all of them, you would lose
them and not know what you are losing.  That is risky and not the
right interface.

In order for undo in Emacs to operate in a predictable and reliable
way, it should undo the changes that you made with your editing.  If
you want to undo the changes that came from CVS, that should be a
separate command, designed to coordinate with CVS.  What I have in
mind is a command to take out the changes that were made between a
certain pair of versions.