Order of merges and the appearance of the revision history

[Erik Bågfors]

I really don't understand what you mean by this.  I ran your script
and checked the two branches b2a and b2b.  Are you expecting them to
be able to pull from eachother?

If you look at "bzr missing " between them, you'll see that they each
have solved a merge, and therefore have one revision missing in one,
and one added in the other.

What happens is that each time you merge, the following happens
1) You run bzr merge
2) You solve any conflicts
3) You verify that the code works
4) You do any changes that needs to be done to make it work (please
note that there is nothing that says that just because you don't get
any conflicts, it works)
5) You commit the "verification/merge"

So, this is done in two different branches, by potentially two
different people.  Because of this, you have different history and as
such cannot use pull

If you want to get into "pull" mode, you can just merge one from a to
b, commit, then pull from b to a. Now you can pull back and fourth as
much as you like.

/Erik

On 4/23/07, Joseph Wakeling <joseph.wakeling at webdrake.net> wrote:
> Something that's started to bother me is that revision history in bzr is
> dependent not just on what patches are in the system but also on what
> order merges and pulls happened.
>
> I've attached a simple little shell script to show what I mean.  It
> creates two divergent branches (1 and 2) and then clones each into a and
> b copies.
>
> 1a merges from 2a, and 2a then pulls from 1a.
>
> 2b merges from 1b, and 1b then pulls from 2b.
>
> Now, if we look at either an a branch or a b branch with bzr viz, the
> revision history is topologically identical, but it's displayed
> differently depending on the order of the merge.
>
> Worse, bzr pull won't let me pull from a b branch to an a branch,
> despite the fact that the _code_ is identical and so, topologically
> speaking, is the revision history.
>
> I wonder if anyone could give some insight into why this is and what
> purpose it serves (if any).
>
>     -- Joe
>
>