merging git repositories history for full history of linux

merging git repositories history for full history of linux

[Yoann Padioleau]

Hi, 

I would like to merge the 3 git repositories of the history
of linux, the one by Dave Jones from linux 0.01 to linux 2.4.0, 
the one by tglx from 2.4.0 to 2.6.12 and the one from 2.6.12
by torvalds until the last version of Linux.

Right now there are 3 repos and I would like only one. I made
some scripts to create a fresh repo, and incorporate each
commit from the 3 repositories mentionned above
(getting the changelog, setting the date), but it takes lots of time
because for instance I can not use the git log -p commitid because
the patch can not be applied as is. So I usually do a checkout
for each commitid and do a manual diff to generate a patch
and apply it to my fresh repo.

Is there a magic command that makes this possible efficiently ?

Re: merging git repositories history for full history of linux

[Junio C Hamano]

Yoann Padioleau <padator@wanadoo.fr> writes:

> I would like to merge the 3 git repositories of the history
> of linux, the one by Dave Jones from linux 0.01 to linux 2.4.0, 
> the one by tglx from 2.4.0 to 2.6.12 and the one from 2.6.12
> by torvalds until the last version of Linux.

I think you can install two grafts (one that says the root in tglx history
has one parent that is tip of Dave Jones history, another that says that
the 2.6.12-rc2 commit which is the root in Linus history has one parent
that is near the tip of tglx history), and if you want the result to use
locally then you are done.  Otherwise you can run filter-branch on the
result, but the future commits from Linus tree will all be different.

Re: merging git repositories history for full history of linux

[Yoann Padioleau]

Junio C Hamano <gitster@pobox.com> writes:

> Yoann Padioleau <padator@wanadoo.fr> writes:
>
>> I would like to merge the 3 git repositories of the history
>> of linux, the one by Dave Jones from linux 0.01 to linux 2.4.0, 
>> the one by tglx from 2.4.0 to 2.6.12 and the one from 2.6.12
>> by torvalds until the last version of Linux.
>
> I think you can install two grafts (one that says the root in tglx history
> has one parent that is tip of Dave Jones history, another that says that
> the 2.6.12-rc2 commit which is the root in Linus history has one parent
> that is near the tip of tglx history), and if you want the result to use
> locally then you are done.  Otherwise you can run filter-branch on the
> result, but the future commits from Linus tree will all be different.

Thanks, I'll try that. 

Also the Dave jones commits have the wrong date. All the 1040 commits
are set to December 2007. I can get all the dates for the different
versions of Linux but is there an easy way then to change the date for
those 1040 commitid ? and also author ? The reasons for this is I want
to use 'git annotate' on the full history of Linux to do some statistics
about the evolution of Linux so I need the good date for each commit.

Also, why the diff produce by git log -p can not be applied as 
is on another git repositories ? I tried to do a script that just
duplicate a git repository by getting the patch for each commit
with 'git log -p' and applies them in turn to a fresh repo with
git applypatch but it fails, git returns some error such as 
"b/Makefile already exist".