Subject: Re: Prepend the history of one git tree to another

From: Andreas Ericsson <[email-masked]>
Date: Mon, 20 Feb 2006 11:14:28 +0100

Thomas Glanzmann wrote:
> Hello,
> I have two trees: blastwave and blastwave.old. blastwave.old is the
> BitKeeper -> CVS -> GIT Tree of the project and blastwave is the newer
> one that I started when I stoped using bitkeeper. What I want is to 
> append the history of blastwave to blastwave.old. The problem is that I
> need to create new commit objects for every commit I want to append to
> the old history. Is there a script which does that for me? Or do I have
> to write this script myself?
> 

Something like this might do the trick, depending on how linear your 
ancestry graph is:

$ cd blastwave
$ first=$(git rev-list HEAD | tail -n 1)
$ git format-patch -k --stdout $first..HEAD > ../blw.mbox
$ cd ../blastwave.old
$ git am -k -3 ../blw.mbox

YMMV though, so set an anchor tag at the HEAD of blastwave.old so you 
can return to it if things go awry. If the history is very non-linear I 
think you'll have to do the same for each and every branch, although 
you'd have to use "git merge-base" to figure out how long to go.

-- 
Andreas Ericsson                   [email-masked]
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231