[MERGE] Branch format 6

[Erik Bågfors]

>
> > Strict history
> > ==============
> > When a branch has a strict history policy, you can only append to it;
> > you cannot change the previous history.  This keeps revnos stable and
> > maintains a consistent view of history.  Strict history can be enabled
> > by setting "strict_history=True" in .bzr/branch/branch.conf
>
> This is https://bugs.launchpad.net/bzr/+bug/73752 by the way, and
> deserves a mention in NEWS, including the command line necessary to
> create such a branch.  I'm happy to see it come in, I think it will be
> helpful in cases like that bug.
>
> I'm not sure 'strict history' really conveys the meaning of this though.
> In that bug john suggests 'preserve_mainline' -- how is that for you?
> Or maybe 'disallow_mainline_changes'.  I would like to convey the facts
> that

First of all, Yes, I love this feature.  However, reading the bug
doesn't make me 100% happy.  I think a command to "Merge this branch
into the other branch but do it locally" is needed. I talked about
"merge --reverse" before as an idea about this.

Basically, If I want to push to a branch that has this property, I have to run

bzr push --> Generates an error message telling me to bind
bzr bind
bzr update
bzr commit
bzr unbind

This is because I don't want to leave my branch bound.

With a merge --reverse thing (yes, the name can change :) ).
bzr push --> Generates an error message telling me to merge --reverse
bzr merge --reverse
bzr commit
bzr push

Ok, it's only one command less but for someone that doesn't work with
checkouts (bound branches), it makes more sense.

Regards,
Erik