Re: Getting correct tree layout when importing svn repo into git

From: Michael J Gruber <git@drmicha.warpmail.net>
Date: Sep 17, 2008, 11:14 UTC
Message-ID: <48D0E6A3.4040703@drmicha.warpmail.net>
In-Reply-To: <cfd18e0f0809170338v168c2991ma3964392e44e0194@mail.gmail.com>

Michael Kerrisk venit, vidit, dixit 17.09.2008 12:38:

Show 65 quoted lines

> Hello Michael,
> 
> On Wed, Sep 17, 2008 at 1:25 AM, Michael J Gruber
> <git@drmicha.warpmail.net> wrote:
>> Michael Kerrisk venit, vidit, dixit 17.09.2008 00:05:
>>> Hello,
>>>
>>> I'm currently trying to import an svn repository, along with its tags,
>>> into git, and everything seems okay except that after the import I
>>> expect to have the following structure to my checked out repository:
>>>
>>>     [root-dir]
>>>         .git
>>>         <checked-out-files>
>>>
>>> But instead I end up with
>>>
>>>     [root-dir]
>>>         .git
>>>         man-pages               <-- name of my svn project
>>>             <checked-out-files>
>>>
>>> I've tried out a few different command-line flag settings but so far I
>>> haven't managed to get the desired layout.  I guess that I'm missing
>>> something trivial, but I haven't worked out what it is so far.
>>>
>>> The commands I'm using to do the import are:
>>>
>>> $ git svn init file:///home/mtk/man-pages-rep/ -t tags -T trunk -b branches
>>> $ git svn fetch
>>>
>>> The svn tags are getting imported okay, since:
>>>
>>> git branch -a | head
>>>   tags/man-pages-2.00
>>>   tags/man-pages-2.01
>>>   ...
>>>   tags/man-pages-3.08
>>>   tags/man-pages-3.09
>>>   trunk
>>>
>>> The following commands show the layout of my svn repo, which is pretty
>>> much standard:
>>>
>>> $ svn list file:///home/mtk/man-pages-rep
>>> branches/
>>> tags/
>>> trunk/
>>> $ svn list file:///home/mtk/man-pages-rep/trunk
>>> man-pages/
>> That's the part that says that your layout is non-standard. What do your
>>  branches and tags look like? Do they have that superfluous "man-pages"
>> part as well?
> 
> $ svn list file:///home/mtk/man-pages-rep/tags
> man-pages-2.00
> man-pages-2.01
> man-pages-2.02
> man-pages-2.03
> ...
> $ svn list file:///home/mtk/man-pages-rep/tags/man-pages-2.00
> man-pages
> $ svn list file:///home/mtk/man-pages-rep/tags/man-pages-2.01
> man-pages
> [and so on]

Bingo!

> $ svn list file:///home/mtk/man-pages-rep/branches
> $
> (i.e., no branches, since this has been a linear svn repo.)

git-svn converts svn tags into git branches (because they can change). So you will get a git repo with lots of branches which are subsets (HEAD commit is in master/trunk) of master/trunk.

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>>> $ svn list file:///home/mtk/man-pages-rep/trunk/man-pages
>>> Changes
>>> Changes.old
>>> Makefile
>>> README
>>> man-pages-3.09.Announce
>>> ...
>>> man7/
>>> man8/
>>> scripts/
>>> $ svn list file:///home/mtk/man-pages-rep/tags
>>> man-pages-2.00/
>>> man-pages-2.01/
>>> ...
>>> man-pages-3.08/
>>> man-pages-3.09/
>>>
>>> What 'git svn init' command do I need to get the layout that I want
>>> for my imported git repo?
>> It depends on the structure of your branches and tags. My guess would be
>> that you have something like tags/man-pages-2.00/man-pages/ etc., in
>> which case you would need a special configuration if you want to get rid
>> of the "man-pages" part. Tells us your structure, we'll tell you the
>> config ;)
> 
> Do you now have enough info above?

Yes, thanks. If you use git-svn init -s (which is equivalent to -T trunk -t tags -b branches) you get an "exact" clone of your svn repo in reasonable time, as you already noticed.

In order to get rid of the "man-pages" path component you can either:

- remove it after the fact using git filter-branch

or

- remove it during the conversion process

For the latter, do the following:

git svn init -s file:///home/mtk/man-pages-rep/

as usual. Then, before the first fetch, make sure your .git/config svn section looks as follows:

[svn-remote "svn"]
        url = file:///home/mtk/man-pages-rep/
        fetch = trunk/man-pages:refs/remotes/trunk
        branches = branches/*/man-pages:refs/remotes/*
        tags = tags/*/man-pages:refs/remotes/tags/*

That is, if you used "git svn init -s" you only have to add "/man-pages" three times on the left hand side of the refspecs. You can also do this using "git config", of course, if you watch out for the shell quoting.

Cheers, Michael