Combining history of two branches

[Matt Mackall]

On Tue, May 05, 2009 at 04:28:43PM -0400, Greg Ward wrote:
> On Tue, May 5, 2009 at 8:08 AM, Tom Widmer <tom.widmer at googlemail.com> wrote:
> > I have two unrelated (in HG terms) repositories:
> > X (77MB) has 500 revisions, 4 named branches (all branched after r10)
> > Y (466 MB) has 20000 revisions, completely linear history (no branches
> > or merges)
> >
> > The tip of Y has an *identical* working tree to X at 10.
> >
> > I want to create a new repository Z. Z will replace X1..10 with the much
> > more exciting history of Y1..20000, thus allowing log and annotate to
> > provide the full, rich history, rather than the truncated version from
> > X. How do I create Z? In effect, I have to replay X11..500 on top of Y.
> 
> Have you tried simply pulling from X into Y?  You'll need "pull -f"
> because they are unrelated repositories, but that's definitely the
> place to start.
 
> > Will MQ allow me to do this (noting that the repositories are
> > unrelated)? Can it cope with the 4 named branches that need to be
> > replayed, or I need to split things up into multiple repositories first?
> > How?

MQ assumes linear history on the 'new' side, so no, this won't work.

> I do not think that MQ (or rebase for that matter) are relevant.  MQ
> and rebase are fundamentally history editing tools.  You're not
> editing history, you're merging two repositories.  You can do that
> with pull, or with export/import, or with bundle/unbundle.

Actually, rebase might work. If you pull -f the two histories into a
combined repo, you can rebase the new history onto the old.

The transplant may also be useful here, as might convert (you can
trick it into grafting history by seeding its shamap).

-- 
Mathematics is the supreme nostalgia of our time.